NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area,...
Transcript of NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area,...
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 1/340
NI 43-101 Technical Report
Prefeasibility StudyToroparu Gold ProjectUpper Puruni River Area, GuyanaEffective Date: May 8, 2013Report Date: May 24, 2013
Report Prepared for
Sandspring Resources Ltd.8000 South Chester Street, Suite 375
Centennial CO 80112
Report Prepared by
SRK Consulting (U.S.), Inc.
7175 West Jefferson Avenue, Suite 3000
Lakewood, CO 80235
SRK Project Number: 349800.020
Signed by QP(s):
Alex Fisher, B.Sc. Geological Engineering, P.E.
Allan Moran, B.Sc., Geol. Eng., RG, CPG
D. Erik Spiller, MMSA
Daniel Lloyd Evans, CFM, PE
Daniel Y. Yang, MEng., PEng.
Dawn H. Garcia, PG, CPG
Fernando Rodrigues, BS Mining, MBA, MAusIMM, MMSAQP
Frank Daviess, MAusIMM, R.M. SME
José Enrique Sánchez Marrou, M.Sc, P.EngKeith Mountjoy, MASc, PGeo
Peter Clarke, BSc Mining, MBA, PE
Thomas A Chapel, CPG, P.E.
Reviewed by:
Bret Swanson, BEng Mining, MAusIMM, MMSAQP
Grant Malensek, P.Eng./P.Geo
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 2/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page i
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table of Contents
1 Summary ....................................................................................................................... 1
1.1 Property Description and Ownership .................................................................................................. 1
1.2 Geology and Mineralization ................................................................................................................ 2
1.3 Mineral Processing and Metallurgical Testing .................................................................................... 4
1.4 Mineral Resource Estimate ................................................................................................................. 5
1.5 Mineral Reserve Estimate ................................................................................................................... 6
1.6 Mining .................................................................................................................................................. 7
1.7 Processing Recovery Methods ........................................................................................................... 9
1.8 Tailings Management Area ............................................................................................................... 10
1.9 Project On-Site Infrastructure ........................................................................................................... 10
1.10 Project Off-site Infrastructure ............................................................................................................ 11
1.11 Project Implementation ..................................................................................................................... 11
1.12 Environmental Studies and Permitting .............................................................................................. 11
1.13 Capital and Operating Costs ............................................................................................................. 14
1.14 Economic Analysis ............................................................................................................................ 16
1.15 Conclusions and Recommendations ................................................................................................ 18
2 Introduction ................................................................................................................ 29
2.1 Terms of Reference and Purpose of the Report ............................................................................... 29
2.2 Qualifications of Consultants ............................................................................................................ 29
2.3
Sources of Information ...................................................................................................................... 31
2.4 Units of Measure ............................................................................................................................... 31
2.5 Glossary and Abbreviated Terms ..................................................................................................... 31
2.5.1 Mineral Resources ................................................................................................................ 31
2.5.2 Mineral Reserves .................................................................................................................. 32
2.5.3 Definition of Terms ................................................................................................................ 32
2.5.4 Abbreviations ......................................................................................................................... 34
3 Reliance on Other Experts ........................................................................................ 38
4 Property Descript ion and Locat ion .......................................................................... 40
4.1 Property Description and Tenure ...................................................................................................... 40
4.2 Location ............................................................................................................................................. 46
5 Accessibi li ty, Climate, Local Resources, Infrast ructure and Physiography ........ 49
5.1 Topography, Elevation and Vegetation ............................................................................................. 49
5.2 Accessibility and Transportation to the Property .............................................................................. 49
5.3 Climate and Length of Operating Season ......................................................................................... 49
5.4 Infrastructure Availability and Sources.............................................................................................. 50
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 3/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page ii
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
5.4.1 Proximity to Population Center .............................................................................................. 50
5.4.2 Power .................................................................................................................................... 50
5.4.3 Water ..................................................................................................................................... 50
5.4.4 Mining Personnel ................................................................................................................... 50
5.4.5 Potential Tailings Storage Areas ........................................................................................... 50
5.4.6 Potential Waste Disposal Areas ............................................................................................ 50
5.4.7 Potential Processing Plant Sites ........................................................................................... 50
5.5 Physiography .................................................................................................................................... 50
6 History ......................................................................................................................... 51
6.1 Alluvial and Saprolite Exploration and Mining - 1997 to 2006 .......................................................... 51
6.2 Bedrock Exploration - 2006 to 2009.................................................................................................. 52
6.3 Sandspring Resources Ltd; Exploration from 2010 to Present ......................................................... 54
6.3.1 2010 Programs ...................................................................................................................... 54
6.3.2 2011 Programs ...................................................................................................................... 56
6.3.3 2012 Programs ...................................................................................................................... 58
6.4 Historic Production ............................................................................................................................ 60
6.5 Previous Metallurgical Testing .......................................................................................................... 60
7 Geological Setting and Mineralization ..................................................................... 62
7.1 Regional Geology – Guiana Shield ................................................................................................... 62
7.2 Regional Geology – Western Guyana .............................................................................................. 63
7.3 Property Geology .............................................................................................................................. 64
7.3.1 Weathering ............................................................................................................................ 65
7.3.2 Lithology ................................................................................................................................ 65
7.3.3 Structure ................................................................................................................................ 66
7.3.4 Alteration ............................................................................................................................... 66
7.4 Mineralization .................................................................................................................................... 67
8 Deposit Type .............................................................................................................. 74
8.1 Geological Model .............................................................................................................................. 76
9 Exploration ................................................................................................................. 77
9.1 Exploration – 2011 and 2012 ............................................................................................................ 77
9.2 Relevant Exploration Work – Post-PEA Drilling ................................................................................ 79
9.2.1 Surveys and Investigations ................................................................................................... 80
9.2.2 Procedures and Parameters ................................................................................................. 80
9.2.3 Sampling Methods and Sample Quality ................................................................................ 80
9.2.4 Significant Results and Interpretation ................................................................................... 81
10 Dri ll ing ......................................................................................................................... 92
10.1 Collar Surveys ................................................................................................................................... 92
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 4/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page iii
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
10.2 Downhole Surveys ............................................................................................................................ 93
10.3 Drill Core Logging ............................................................................................................................. 93
10.4 Interpretation ..................................................................................................................................... 93
10.5 Results .............................................................................................................................................. 94
11 Sample Preparation, Analysis and Security ............................................................ 98
11.1 Sampling Methods ............................................................................................................................ 98
11.2 Security Measures ............................................................................................................................ 98
11.3 Sample Preparation .......................................................................................................................... 98
11.4 Sample Analysis ................................................................................................................................ 98
11.5 QA/QC Procedures ........................................................................................................................... 99
11.5.1 QA/QC Results ...................................................................................................................... 99
11.5.2 QA/QC Actions ...................................................................................................................... 99
11.6 Opinion on Adequacy ...................................................................................................................... 100
12 Data Verification ....................................................................................................... 105
12.1 Procedures ...................................................................................................................................... 105
12.2 Limitations ....................................................................................................................................... 106
12.3 Opinion on Data Adequacy ............................................................................................................. 106
13 Mineral Processing and Metallurgical Testing ...................................................... 107
13.1 Summary ......................................................................................................................................... 107
13.2 Metallurgical Testing ....................................................................................................................... 107
13.3 Mineralogy ....................................................................................................................................... 108
13.3.1 Sulfide and Gangue Minerals .............................................................................................. 108
13.3.2 Gold Deportment ................................................................................................................. 108
13.4 Comminution Tests (ACO/LCO) ..................................................................................................... 109
13.4.1 Grindability .......................................................................................................................... 109
13.4.2 Abrasion Index .................................................................................................................... 109
13.4.3 HPGR Testing ..................................................................................................................... 109
13.5 Gravity Separation (ACO/LCO) ....................................................................................................... 110
13.5.1 Gravity Separation (ACO) ................................................................................................... 111
13.5.2 Gravity Separation (LCO) .................................................................................................... 111
13.6 Flotation Testwork (ACO/LCO) ....................................................................................................... 111
13.6.1 Phase 1 ............................................................................................................................... 111
13.6.2 Phase 2 ............................................................................................................................... 111
13.6.3 Phase 2 Extension .............................................................................................................. 112
13.6.4 Gold Ore with Average Copper (ACO) ................................................................................ 113
13.6.5 Gold Ore with Low Copper (LCO) ....................................................................................... 114
13.7 Cyanide Leaching (ACO/LCO) ........................................................................................................ 115
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 5/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page iv
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
13.7.1 Phase 1 ............................................................................................................................... 115
13.7.2 Phase 2 ............................................................................................................................... 116
13.7.3 Phase 2 Extension .............................................................................................................. 116
13.7.4 Locked Cycle Test Cleaner Tailing Cyanidation (ACO) ...................................................... 117
13.7.5 Gravity Concentrate Intensive Cyanidation (ACO) ............................................................. 117
13.7.6 Gravity Concentrate Intensive Cyanidation (LCO) .............................................................. 118
13.7.7 Gravity Tailing Bulk Cyanidation ......................................................................................... 118
13.7.8 Rougher Concentrate Cyanidation (LCO) ........................................................................... 118
13.7.9 Comparison of Cyanide Leaching of Gravity Tailing and Flotation Products for ACO andLCO ..................................................................................................................................... 119
13.8 Saprolite Test Work Program 2012-2013 ....................................................................................... 122
13.8.1 Gravity Separation Testwork ............................................................................................... 122
13.8.2 Flotation Testwork ............................................................................................................... 122
13.8.3 Cyanidation Testwork .......................................................................................................... 123
14 Mineral Resource Estimate ..................................................................................... 127
14.1 Drillhole Database ........................................................................................................................... 127
14.2 Targeted In-fill Drilling ..................................................................................................................... 127
14.3 Geologic Model ............................................................................................................................... 129
14.3.1 External Domain Envelope .................................................................................................. 130
14.3.2 Anisotropy Model ................................................................................................................. 131
14.3.3 Internal Domain Envelopes ................................................................................................. 131
14.4 Domain Analysis & Grade Capping ................................................................................................ 131
14.5 Compositing .................................................................................................................................... 133
14.6 Bulk Density .................................................................................................................................... 133
14.7 Block Model ..................................................................................................................................... 135
14.8 Search Orientation/ Anisotropy Model ............................................................................................ 135
14.9 Grade Assignment .......................................................................................................................... 136
14.10 Mineral Resource Classification/Confidence Assignment .............................................................. 137
14.11 Resource Statement ....................................................................................................................... 138
14.12 Model Validation & Mineral Resource Sensitivity ........................................................................... 140
14.12.1
Visual Comparison .......................................................................................................... 140
14.12.2 Comparative Statistics .................................................................................................... 141
14.12.3 Swath Analysis ................................................................................................................ 142
15 Mineral Reserve Estimate ........................................................................................ 167
15.1 Conversion Assumptions, Parameters and Methods ...................................................................... 167
15.2 Reserve Estimate ............................................................................................................................ 168
16 Mining Methods ........................................................................................................ 171
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 6/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page v
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
16.1 Proposed Mining Method ................................................................................................................ 172
16.2 Geotechnical Mine Design Parameters .......................................................................................... 172
16.3 Pit Optimization ............................................................................................................................... 173
16.3.1 Mineral Resource Models.................................................................................................... 173
16.3.2 Topographic Data ................................................................................................................ 173
16.3.3 Optimization Constraints ..................................................................................................... 173
16.3.4 Optimization Parameters ..................................................................................................... 174
16.3.5 Optimization Process .......................................................................................................... 175
16.3.6 Optimization Results ........................................................................................................... 176
16.3.7 South-East Deposit ............................................................................................................. 177
16.4 Design Criteria ................................................................................................................................ 177
16.5 Pit Phase and Ultimate Pit Designs ................................................................................................ 179
16.6 Mine Production Schedule .............................................................................................................. 179
16.6.1 Mine Production .................................................................................................................. 179
16.7 Waste and Low Grade Stockpile Design ........................................................................................ 182
16.8 Mining Equipment Requirements .................................................................................................... 186
16.8.1 Summary ............................................................................................................................. 186
16.8.2 General Parameters and Fleet Selection ............................................................................ 186
16.8.3 Drilling .................................................................................................................................. 188
16.8.4 Blasting ................................................................................................................................ 189
16.8.5 Loading ................................................................................................................................ 190
16.8.6 Hauling ................................................................................................................................ 192
16.8.7 Auxiliary Equipment ............................................................................................................. 194
16.9 Mine Dewatering ............................................................................................................................. 195
16.9.1 Water Data Sources ............................................................................................................ 195
16.9.2 Water from Precipitation ...................................................................................................... 195
16.9.3 Groundwater Inflow ............................................................................................................. 195
16.9.4 Dewatering System ............................................................................................................. 195
17 Recovery Methods ................................................................................................... 208
17.1 Summary ......................................................................................................................................... 208
17.2 Overview ......................................................................................................................................... 208
17.3 Design Basis ................................................................................................................................... 208
17.3.1 Preproduction-Phase ........................................................................................................... 208
17.3.2 Phase 1: 15,000 t/d ACO and Saprolite .............................................................................. 209
17.3.3 Phase 2: 15,000 t/d LCO with 7,500 t/d ACO ..................................................................... 209
17.4 Mass and Water Balance ................................................................................................................ 210
17.5 Process Design Criteria .................................................................................................................. 210
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 7/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page vi
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
17.5.1 Primary/Secondary Crushing and Stockpile ........................................................................ 210
17.5.2 Grinding ............................................................................................................................... 211
17.5.3 Gravity Circuit and Intense Cyanide Leaching .................................................................... 212
17.5.4 Rougher Flotation Circuit..................................................................................................... 212
17.5.5 Regrind Circuit ..................................................................................................................... 212
17.5.6 Cleaner Flotation Circuit ...................................................................................................... 212
17.5.7 Concentrate Dewatering Circuit .......................................................................................... 213
17.5.8 CIP Circuit ........................................................................................................................... 213
17.5.9 Desorption ........................................................................................................................... 214
17.5.10 Electrowinning and Gold Room ...................................................................................... 215
17.5.11 Carbon Regeneration ...................................................................................................... 215
17.5.12 CIP Tails Detoxification and Tails Dewatering ................................................................ 215
17.5.13 Reagents ......................................................................................................................... 216
18 Project Infrastructure............................................................................................... 218
18.1 On-Site Infrastructure ...................................................................................................................... 218
18.1.1 Geotechnical ....................................................................................................................... 218
18.1.2 Site Water Management ...................................................................................................... 219
18.1.3 Service Roads and Bridges ................................................................................................. 220
18.1.4 Mine Operations Support Facilities ..................................................................................... 220
18.1.5 Process Support Facilities ................................................................................................... 221
18.1.6 Man Camp ........................................................................................................................... 222
18.1.7 Additional Support Facilities ................................................................................................ 222
18.1.8 Power Supply and Distribution ............................................................................................ 223
18.1.9 Water Supply ....................................................................................................................... 223
18.1.10 Waste Water Treatment and Solid Waste Disposal ........................................................ 224
18.2 Tailings Management Area ............................................................................................................. 224
18.3 Off-Site Infrastructure and Logistic Requirements .......................................................................... 225
18.3.1 Off-Site Infrastructure .......................................................................................................... 225
19 Market Studies and Contracts ................................................................................ 228
19.1 Summary of Information .................................................................................................................. 228
19.2 Market Studies ................................................................................................................................ 228
19.2.1 Gold in Dore’ ....................................................................................................................... 228
19.2.2 Gold & Copper in Concentrate ............................................................................................ 228
19.3 Commodity Price Projections .......................................................................................................... 228
19.4 Contracts and Status....................................................................................................................... 229
19.4.1 Metal Treatment, Refining, and Transportation .................................................................. 229
19.4.2 Supplier & Service Contracts .............................................................................................. 229
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 8/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page vii
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
19.5 Indicative Terms .............................................................................................................................. 229
19.5.1 Doré Net Smelter Return ..................................................................................................... 229
19.5.2 Copper Concentrate Net Smelter Return ............................................................................ 229
19.5.3 Diesel and Fuel Oil Prices ................................................................................................... 230
19.6 Royalties & Taxes ........................................................................................................................... 230
20 Environmental Studies, Permit ting and Social or Community Impact ................ 231
20.1 Environmental Study Results .......................................................................................................... 232
20.1.1 Results of Baseline Studies................................................................................................. 233
20.1.2 Results of Geochemical Studies of Tailings, Waste Rock and Low Grade Ore ................. 237
20.2 Environmental Issues ...................................................................................................................... 242
20.3 Operating and Post Closure Requirements and Plans ................................................................... 242
20.4 Post-performance or Reclamations Bonds ..................................................................................... 243
20.5 Social and Community .................................................................................................................... 243
20.6 Mine Closure ................................................................................................................................... 245
20.7 Reclamation Measures during Operations and Project Closure ..................................................... 246
20.7.1 Tailings Management Area ................................................................................................. 246
20.7.2 Open Pits ............................................................................................................................. 247
20.7.3 Waste Rock Storage Areas ................................................................................................. 247
20.7.4 Plant Site and Facilities ....................................................................................................... 247
20.8 Closure Monitoring .......................................................................................................................... 247
20.9 Reclamation and Closure Cost Estimate ........................................................................................ 248
21 Capital and Operating Costs [All ] ........................................................................... 251
21.1 Summary ......................................................................................................................................... 251
21.2 Capital Cost Estimate...................................................................................................................... 252
21.2.1 Mining Capital Cost ............................................................................................................. 252
21.2.2 Process and On-Site Infrastructure Capital Cost ................................................................ 254
21.2.3 Off-Site Infrastructure Capital Cost ..................................................................................... 256
21.2.4 Owner’s Cost ....................................................................................................................... 258
21.2.5 Sustaining Capital Costs ..................................................................................................... 259
21.3 Operating Cost Estimates ............................................................................................................... 263
21.3.1 Summary ............................................................................................................................. 263
21.3.2 Mining Operating Costs ....................................................................................................... 264
21.3.3 Process Operating Costs .................................................................................................... 269
21.3.4 Off-Site Infrastructure Operating Cost ................................................................................. 276
21.3.5 General & Administrative Costs .......................................................................................... 276
22 Economic Analysis .................................................................................................. 278
22.1 Method of Evaluation ...................................................................................................................... 278
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 9/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page viii
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
22.2 Input Parameters............................................................................................................................. 279
22.3 Cashflow Forecasts and Annual Production Forecasts .................................................................. 283
22.4 Sensitivity Analysis.......................................................................................................................... 285
23 Adjacent Proper ties ................................................................................................. 290
24 Other Relevant Data and Information ..................................................................... 291
25 Interpretation and Conclusions .............................................................................. 292
25.1 Geology and Resources ................................................................................................................. 292
25.2 Mining and Reserves ...................................................................................................................... 292
25.3 Metallurgy, Processing and Recoveries ......................................................................................... 293
25.4 Infrastructure ................................................................................................................................... 294
25.5 Project Implementation ................................................................................................................... 294
25.6 Environmental Studies and Permitting ............................................................................................ 295
25.7
Economic Analysis .......................................................................................................................... 296
25.8 Risks and Uncertainties .................................................................................................................. 296
26 Recommendations ................................................................................................... 298
26.1 Recommended Work Programs and Costs .................................................................................... 298
26.1.1 Phase I ................................................................................................................................ 298
26.1.2 Phase II ............................................................................................................................... 303
26.1.3 Summary of Recommended Work Program Costs ............................................................. 305
27 References ................................................................................................................ 306
List of TablesTable 1.4.1 Resource Statement @ 0.30 g/t Au cut-off as of March 31, 2013 .................................................. 6
Table 1.5.1: March 31, 2013 Mineral Reserve Estimate ................................................................................... 7
Table 1.6.1: Planned Mine Production Schedule .............................................................................................. 9
Table 1.13.1: Summary of Capital Costs by Area ........................................................................................... 15
Table 1.13.2: Operating Cost Life of Mine, US$000s ...................................................................................... 16
Table 1.14.1: Project Evaluation Economic Results ......................................................................................... 18
Table 2.5.3.1: Definition of Terms ................................................................................................................... 32
Table 2.5.4.1: Abbreviations ............................................................................................................................ 34
Table 4.1.1: Land Tenure – Medium Scale Prospecting Permits .................................................................... 41
Table 4.1.2: Land Tenure – Mining Permits .................................................................................................... 44
Table 4.1.3: Land Tenure – Prospecting Licenses .......................................................................................... 44
Table 6.2.1: Toroparu 2008 Mineral Resources ............................................................................................... 53
Table 6.3.1.1: Toroparu 2010 Mineral Resources ........................................................................................... 55
Table 6.3.1.2: Toroparu 2010 Updated Mineral Resources ............................................................................ 55
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 10/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page ix
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 6.3.2.1: Toroparu 2011 Mineral Resources in a PEA ............................................................................ 58
Table 6.3.3.1: PEA Mineral Resources, Effective date of January 2012 ......................................................... 60
Table 8.1: Primary Geological and Mineralization Features of Several Gold and Gold –Copper Deposits ofthe Guiana Craton ............................................................................................................................... 75
Table 9.1.1: Saprolite Sampling in 2011 and 2012 .......................................................................................... 77
Table 9.1.2: 2012 RC Reconnaissance Drilling Program ................................................................................. 78
Table 10.1: Summary of the Core Drill Programs on the Toroparu Resource Zone ....................................... 92
Table 10.5.1: Example of Drillhole assays – Hole TPD-022 ............................................................................ 94
Table 12.1.1 SRK Spot Sample Verification Assays ...................................................................................... 106
Table 13.2.1: Test Work Programs and Reports ........................................................................................... 108
Table 13.4.1.1: Summary of JK Tech/SMC Data (2011) ............................................................................... 109
Table 13.4.1.2: Grindability Data ................................................................................................................... 109
Table 13.4.3.1: Summary of HPGR Test Findings ........................................................................................ 110
Table 13.5.1: Gravity Separation Results Summary for Phase 1, Phase 2, Phase 2 Extension .................. 110
Table 13.6.4.1: ACO Combined Gravity and Flotation and Recovery of Au and Ag ..................................... 113
Table 13.6.4.2: Locked Cycle Test Results ................................................................................................... 114
Table 13.6.4.3: ACO Combined Results from Gravity Separation and LCT Tests ....................................... 114
Table 13.6.5.1: Combined Gravity and Flotation gold Recovery for the LCO Composites ........................... 115
Table 13.7.4.1: ACO Gravity, Cleaner Flotation, and Cleaner Tail Leach Summary .................................... 117
Table 13.7.7.1: LCO Combined Results from Gravity Separation and Gravity Tailing Cyanidation Tests ... 118
Table 13.7.8.1: LCO Combined Results from Gravity Separation, Rougher Flotation and RougherConcentrate Leaching........................................................................................................................ 119
Table 13.7.9.1: Overall Gold Recovery for ACO Composite, Gravity and Gravity Tailing Cyanide Leaching119
Table 13.7.9.2: Overall Gold Recovery for ACO Composite, Gravity and Gravity Tailing Rougher Flotation120
Table 13.7.9.3: Overall Gold Recovery for ACO Composite, Gravity, Gravity Tailing Cleaner Flotation andCleaner Tail cyanide Leaching .......................................................................................................... 120
Table 13.7.9.4: Overall Gold Recovery for LCO Composites, Gravity and Gravity Tailing Cyanide Leaching120
Table 13.7.9.5: Overall Gold Recovery for LCO Composites, Gravity and Gravity Tailing Rougher Flotationand Rougher Concentrate Cyanide Leaching ................................................................................... 120
Table 13.7.9.6: Copper Extraction and Cyanide Consumption for Gravity Tails Leaching of ACO .............. 121
Table 13.7.9.7: Copper Extraction and Cyanide Consumption for Cleaner Tails Leaching of ACO ............. 121
Table 13.7.9.8: Copper Extraction and Cyanide Consumption for Gravity Tails Leaching of LCO ............... 121
Table 13.7.9.9: Copper Extraction and Cyanide Consumption for Rougher Concentrate Leaching of LCO 122
Table 14.2.1: Final Ranking of Proposed In-fill Drillholes Based on Expected Oz Au and Pit Shell ............. 129
Table 14.4.1 Assay Summary Statistics by Domain ....................................................................................... 132
Table 14.4.2: Assay Capping Thresholds ...................................................................................................... 132
Table 14.4.3 Capped Assay Summary Statistics by Domain ......................................................................... 133
Table 14.5.1: Composite Summary Statistics by Domain ............................................................................. 133
Table 14.6.1: Bulk Density by Major Rock types ............................................................................................ 134
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 11/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page x
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 14.6.2: Bulk Density Data by Rock Code ............................................................................................ 134
Table 14.6.3: Summary of Bulk Density Data ............................................................................................... 135
Table 14.7.1: Toroparu Model Limits .............................................................................................................. 135
Table 14.9.1: Kriging Parameters .................................................................................................................. 136
Table 14.9.2 Search Neighborhood Strategy ................................................................................................. 137
Table 14.9.3 Confidence Classification Scheme ............................................................................................ 137
Table 14.11.1: Resource Reporting Cut-offs ................................................................................................. 138
Table 14.11.2: Resource Statement @ 0.30 g/t Au cut-off as of March 31, 2013 ........................................ 139
Table 14.11.3: Mineral Resource Estimate M&I Sensitivity Analysis – All Zones ......................................... 140
Table 14.11.4: Mineral Resource Estimate Inferred Sensitivity Analysis – All Zones ................................... 140
Table 14.12.2.1: Fresh Rock Composite/Model Statistics ............................................................................. 141
Table 14.12.2.2: Saprolite Composite/Model Statistics ................................................................................. 141
Table 14.12.2.3: Fresh Rock Inventory – Alternative Estimators Au ............................................................. 142
Table 14.12.2.4: Fresh Rock Inventory – Alternative Estimators Cu ............................................................ 142
Table 15.1.1: In-pit Cut-off Grade Calculation Results .................................................................................. 168
Table 15.2.1: Mineral Reserve Estimate as of March 31, 2013 .................................................................... 169
Table 16.2.1: Recommended Pit Slope Configurations ................................................................................ 173
Table 16.3.1.1: Block Model Block Sizes ...................................................................................................... 173
Table 16.3.4.1: Processing Parameters ......................................................................................................... 175
Table 16.3.4.2: Optimization Parameters (Base Case) ................................................................................. 175
Table 16.3.6.1: Whittle™ Results for Toroparu .............................................................................................. 176
Table 16.3.7.1: Whittle™ Results for South East Deposit .............................................................................. 177
Table 16.4.1 shows the final pit design parameters. ...................................................................................... 177
Table 16.4.1: Final Design Parameters ......................................................................................................... 177
Table 16.4.2: Toroparu Pit Final Geotech Pit Design Parameters Used in Updated PEA ............................ 178
Table 16.4.3: Toroparu and South-East Pits Geotech Pit Design Parameters .............................................. 178
Table 16.6.1.1: Planned Mine Production Schedule ..................................................................................... 180
Table 16.6.1.2: Production Mill Schedule (Mill Feed) .................................................................................... 181
Table 16.7.1: Toroparu Waste Dump Parameters ........................................................................................ 183
Table 16.7.2: Ore Stockpile Inventories ........................................................................................................ 185
Table 16.8.6.1: Toroparu Haulage Truck Speeds (km/hr) ............................................................................. 193
Table 17.5.1.1: Primary Jaw Crusher ............................................................................................................ 210
Table 17.5.1.2: Secondary Crusher ............................................................................................................... 211
Table 17.5.2.1: HPGR Phase 1 ..................................................................................................................... 211
Table 17.5.2.2 Ball Mill, Phase 1 .................................................................................................................... 211
Table 17.5.2.3: HPGR Phase 2 ..................................................................................................................... 212
Table 17.5.2.4 Ball Mill, Phase 2 .................................................................................................................... 212
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 12/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page xi
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 17.5.4.1: Rougher Flotation Circuit ...................................................................................................... 212
Table 17.5.6.1: 1st Cleaner Flotation Circuit ................................................................................................. 213
Table 17.5.6.2: 1st Cleaner Scavenger Flotation Circuit ............................................................................... 213
Table 17.5.6.3: 2nd Cleaner Flotation Circuit ................................................................................................ 213
Table 17.5.8.1: CIP - Phase 1 ....................................................................................................................... 214
Table 17.5.8.2: CIP - Phase 2 ....................................................................................................................... 214
Table 17.5.9.1: Desorption Operation ........................................................................................................... 214
Table 17.5.9.2: Acid Wash ............................................................................................................................ 214
Table 17.5.9.3: Elution ................................................................................................................................... 214
Table 17.5.10.1: Electrowinning .................................................................................................................... 215
Table 17.5.10.2: Smelting .............................................................................................................................. 215
Table 17.5.11.1: Kiln Carbon Dewatering Screen ......................................................................................... 215
Table 17.5.11.2: Barren Carbon Dewatering Screen .................................................................................... 215
Table 20.1: Environmental Permits ............................................................................................................... 232
Table 20.1.1.1: Monitor Well Locations and Groundwater Elevation Data .................................................... 235
Table 20.1.1.2: International Status of Species ............................................................................................. 237
Table 20.5.1: Summary of Socio-cultural Impacts and Mitigation Strategies ................................................ 244
Table 21.1.1: Summary of Capital Costs by Area ......................................................................................... 251
Table 21.2.1.1: Initial Mining Equipment Capital Cost Estimate (US$000s) ................................................. 253
Table 21.2.2.1: Initial Capital Cost Estimate – Process and On-site Summary ............................................ 255
Table 21.2.3.1: Off-site Infrastructure Capital Cost Estimate (US$ millions) ................................................ 258
Table 21.2.4.1: Major Components of Owner’s Costs ($US million) ............................................................. 258
Table 21.2.5.1: LoM Mining Equipment Sustaining Capital Cost Estimate (US$000s) ................................. 260
Table 21.2.5.2: TMA Facilities Sustaining Capital Cost Estimate ................................................................. 262
Table 21.2.5.3: Onsite Infrastructure Sustaining Capital Cost Estimate ....................................................... 262
Table 21.3.1.1: Operating Cost Life –of Mine, US$ x 1,000 .......................................................................... 263
Table 21.3.1.2: Annual Operating Cost, US$ x 1,000 .................................................................................... 263
Table 21.3.2.2: Mine Hourly Labour Requirements ....................................................................................... 269
Table 21.3.3.1: Plant Operating Costs (LoM) ................................................................................................ 269
Table 21.3.3.2: Plant Power Requirements ................................................................................................... 270
Table 21.3.3.3: Reagent Consumption Rates and Cost – Preproduction ..................................................... 271
Table 21.3.3.4: Reagent Consumption Rates and Cost – Phase 1 .............................................................. 272
Table 21.3.3.5: Reagent Consumption Rates and Cost – Phase 2 .............................................................. 273
Table 21.3.3.6: Consumables Cost Estimate – Pre-production .................................................................... 274
Table 21.3.3.7: Consumables Cost Estimate – Phase 1 ............................................................................... 275
Table 21.3.3.8: Consumables Cost Estimate – Phase 2 ............................................................................... 275
Table 22.2.1: Key Criteria, Principal Assumptions and Input Parameters Used in the Base Case .............. 280
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 13/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page xii
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 22.2.2: Project Stages ......................................................................................................................... 281
Table 22.2.3 Production Parameters .............................................................................................................. 282
Table 22.3.1: Project Evaluation Economic Results ....................................................................................... 284
Table 22.3.2: Summary of LoM Production and Cashflow ............................................................................. 285
Table 22.3.3 Project LoM Annual Production and Revenues......................................................................... 285
Table 22.4.1: Sensitivity to Capital Costs ....................................................................................................... 286
Table 22.4.2: Sensitivity to Operating Costs .................................................................................................. 286
Table 22.4.3: Sensitivity to Metal Prices ......................................................................................................... 286
Table 26.1.1.1: Condemnation Drilling Program ........................................................................................... 299
Table 26.1.3.1: Cost Summary for Recommended Work for FS Completion ............................................... 305
List of FiguresFigure 1.1.1: Upper Puruni Property and Toroparu Deposit Location Map ..................................................... 23
Figure 1.6.1: Toroparu Mine Site ..................................................................................................................... 24
Figure 1.6.2: Mine Plan Progress Maps - Year 14 End, Ultimate Pit .............................................................. 25
Figure 1.7.1: Overall Simplified Process Flow Diagram .................................................................................. 26
Figure 1.9.1: Toroparu Mine Overall Site Including Tailings Management Area ............................................. 27
Figure 1.14.1: NPV Sensitivity ......................................................................................................................... 28
Figure 4.2.1: Upper Puruni Property Claim Map ............................................................................................. 47
Figure 4.2.2: Detail of Toroparu Deposit ......................................................................................................... 48
Figure 7.1.1: Geological Sketch of the Guyana ............................................................................................... 69
Figure 7.2.1: Upper Puruni District: Regional Geological Sketch ................................................................... 70
Figure 7.3.2.1: Geological Sketch Map of the Toroparu Deposit Area ............................................................ 71
Figure 7.3.2.2: Geological Sketch of Drill Section 2+50 W Center Part of the Main East Zone (Toroparudeposit) ................................................................................................................................................ 72
Figure 7.4.1: Drillhole Plan Map with Gold Grade Distribution in Resource Areas .......................................... 73
Figure 9.1.1: Saprolite Auger Sampling - Toroparu .......................................................................................... 82
Figure 9.2.4.1: Toroparu – 2013 Drillhole Collar Locations and traces – All Holes (486), Current MineralizedShape .................................................................................................................................................. 83
Figure 9.2.4.2: Toroparu – Drillhole Collar Locations – PEA Drilling through Aug. 2011 (342 holes).............. 84
Figure 9.2.4.3: Toroparu – Drillhole Collar Locations – Post PEA and Pre Targeted In-Fill (166 holes) ......... 85
Figure 9.2.4.4: Toroparu – Drillhole Collar Locations – Targeted In-Fill (Aug-Dec 2012) ................................ 86
Figure 9.2.4.5: Cross-Section showing Block Classification and Areas of Targeted Inferred Mineralization . 87
Figure 9.2.4.6: Cross-Section showing Block Au Grade and Areas of Targeted Inferred Mineralization ....... 88
Figure 9.2.4.7: Cross-Section showing Targeted Inferred Blocks and In-Fill Drill Data .................................. 89
Figure 9.2.4.8: Cross-Section Showing Current Block Classification and Areas of Targeted InferredMineralization that have been Converted to Measured and Indicated ................................................ 90
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 14/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page xiii
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Figure 9.2.4.9: Cross-Section showing Block Grade for Current Resource model ......................................... 91
Figure 10.1: Toroparu – Plan Map of Drillholes and Traces, Showing Mineralized Envelope ........................ 96
Figure 10.3.1: Example of Un-cut Core Photograph for Drillhole TPD-103 .................................................... 97
Figure 11.5.1.1: Check Assay Scatter Plot of Actlab’s versus Acme Lab’s Au Assays ................................. 101
Figure 11.5.1.2: Check Assay Scatter Plot of Actlab’s versus Acme Lab’s Cu Assays ................................. 102
Figure 11.5.1.3: Check Assay Scatter Plot of Actlab’s versus Acme Lab’s Au Pulp Duplicate Assays ......... 103
Figure 11.5.1.4: Scatter Plot of Actlab’s versus Acme Lab’s Au Coarse Duplicate Assays ........................... 104
Figure 13.6.2.1: Effect of Sample P80 on Rougher Tailings Grade of Au and Cu ......................................... 124
Figure 13.8.3.1: Au Cyanide Leach Kinetics for Saprolite Fines ................................................................... 125
Figure 13.8.3.2: Au Cyanide Leach Kinetics for Coarse Saprolite ................................................................ 126
Figure 14.3.1: Toroparu Plan ......................................................................................................................... 143
Figure 14.3.1.1: Toroparu Plan “Fresh Rock” (grey) & “Saprolite” (orange) Domains .................................. 144
Figure 14.3.1.2: Toroparu Plan “Fresh Rock” (grey) & “Saprolite” (orange) Domains .................................. 145
Figure 14.3.2.1: Toroparu Perspectives “Fresh Rock” (grey) & “Anisotropy “ (red) ...................................... 146
Figure 14.3.3.1: Toroparu Domains ............................................................................................................... 147
Figure 14.3.3.2: Toroparu Model, Elevation -90 & Elevation -240, Mineralized/non Mineralized (green/grey)148
Figure 14.3.3.3: Toroparu Model Cross Sections, Mineralized/non Mineralized (green/grey) .................... 149
Figure 14.4.1: Lognormal Probability Plot, Au (g/t) Assays ........................................................................... 150
Figure 14.4.2: Lognormal Probability Plot, Cu (%) Assays ........................................................................... 151
Figure 14.6.1: Histogram of Bulk Density Data - Toroparu ........................................................................... 152
Figure 14.8.1: Variogram, Au (g/t) Modeled Anisotropic & Isotropic Variogram ........................................... 153
Figure 14.8.2: Variogram, Au (g/t) Modeled Anisotropic Variogram ............................................................. 154
Figure 14.8.3: Variogram, Cu (%) Modeled Anisotropic & Isotropic Variogram ............................................ 155
Figure 14.8.4: Variogram, Cu (%) Modeled Anisotropic Variogram .............................................................. 156
Figure 14.8.5: Anisotropy Points ................................................................................................................... 157
Figure 14.9.1: Resource Model Plans -160 Elevation -250 Elevation ........................................................... 158
Figure 14.9.2: Resource Model Representative Cross Sections................................................................... 159
Figure 14.9.3: Resource Model Perspective ................................................................................................. 160
Figure 14.10.1: Resource Model Confidence Classification -225, -200, -100 Plan Views ............................ 161
Figure 14.11.1: Optimized Resource Pits ...................................................................................................... 162
Figure 14.11.2: Cut-off/Price ......................................................................................................................... 163
Figure 14.12.3.1: Vertical Swath Diagram ...................................................................................................... 164
Figure 14.12.3.2: North-South Swath Diagram ............................................................................................. 165
Figure 14.12.3.3: East-West Swath Diagram ................................................................................................ 166
Figure 15.1.1: Cut-off Grade Calculation Graph (by different Gold selling price).......................................... 170
Figure 16.3.6.1: Toroparu Pit Optimization Results (Cashflow) .................................................................... 197
Figure 16.3.7.1: South-East Pit Optimization Results (Cashflow) ................................................................. 198
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 15/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page xiv
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Figure 16.4.1: Toroparu Pit Geotechnical Sectors ........................................................................................ 199
Figure 16.5.1: Toroparu Pit Phase Design .................................................................................................... 200
Figure 16.5.2: South-East Pit Phase Design ................................................................................................. 201
Figure 16.5.3: Toroparu Final Pit Design – Measured and Indicated Blocks ................................................ 202
Figure 16.5.4: South-East Final Pit Design - Measured and Indicated Blocks .............................................. 203
Figure 16.5.5: Mine Plan Progress Maps - Year 5 End ................................................................................. 204
Figure 16.5.6: Mine Plan Progress Maps - Year 10 End ............................................................................... 205
Figure 16.6.11: Planned Mine Production Schedule (Material Movement) ................................................... 206
Figure 16.7.1: Pit and Waste Dump Locations .............................................................................................. 207
Figure 18.2.1: Tailings Management Area ..................................................................................................... 227
Figure 20.1.1.1: Location of Surface Water Samples .................................................................................... 249
Figure 20.1.1.2: Location of Well Sites .......................................................................................................... 250
Figure 22.1.1: Cumulative Cash Flow ............................................................................................................ 287
Figure 22.4.1: IRR Sensitivity ........................................................................................................................ 288
Figure 22.4.2: NPV Sensitivity to Discount Rate ............................................................................................ 289
Appendices Appendix A: Certificates of Authors
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 16/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 1
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
1 SummaryThis report is as a National Instrument 43-101 (NI 43-101) Technical Report on the Prefeasibility
Study of the Toroparu Gold Project (Toroparu Project or Project) prepared for Sandspring Resources
Ltd. (Sandspring) by SRK Consulting (U.S.), Inc. (SRK), Tetra Tech (Tt), Klohn Crippen Berger(KCB), Knight Piésold (KP), and FMG Engineering (FMG), (collectively the Consultants). Sandspring
is a Canadian based company continued under the laws of Ontario and trades on the TSX Venture
Exchange (TSX-V) under the symbol “SSP”. The quality of information, conclusions, and estimates
contained herein is consistent with the level of effort involved in the Consultant’s services, based on:
i) information available at the time of preparation, ii) data supplied by outside sources, and iii) the
assumptions, conditions, and qualifications set forth in this report. This report is intended for use by
Sandspring subject to the terms and conditions of its contract with SRK and relevant securities
legislation. The contract permits Sandspring to file this report as a Technical Report with Canadian
securities regulatory authorities pursuant to NI 43-101, Standards of Disclosure for Mineral Projects.
Except for the purposes legislated under provincial securities law, any other uses of this report by
any third party is at that party’s sole risk. The responsibility for this disclosure remains withSandspring. The user of this document should ensure that this is the most recent Technical Report
for the property as it is not valid if a new Technical Report has been issued.
1.1 Property Descr ipt ion and Ownership
The Toroparu Deposit is located within Sandspring’s 98,214 hectare mineral exploration concession
area in the Upper Puruni River Area, Region 7 of northwestern Guyana, South America (referred to
as the “Upper Puruni Property” or the “Property”).
The airstrip at the Property is located at 06° 27’ North Latitude and 60° 03’ West Longitude, a
position approximately 220 km by air west southwest of Georgetown, the capital city of Guyana. The
2,500 ft airstrip at the Property camp is accessible by charter aircraft from Ogle airfield in
Georgetown. The 220 km trip takes approximately one hour.
Access to the Upper Puruni Property and the Toroparu Project by road includes 128 km via paved
highway from Georgetown to Bartica, a ferry crossing of the Essequibo River at Bartica to Itaballi,
200 km of gravel road to the Upper Puruni Property south gate, and 30 km within the property to the
Toroparu Project. Overland travel time is approximately 12 to 16 hours in the dry season from
August to May.
Heavy equipment and cargo is transportable by small, ocean going vessels and barges on the
Essequibo River to Itaballi. There it is loaded on to trucks for the 7-10 hour, 225 km overland journey
to the Toroparu Project crossing the Puruni River by ferry at the town of Puruni Landing, 60 km from
Itaballi (Figure 1.1.1).
The Property is comprised of seven Small Scale claims, 167 contiguous Medium Scale Prospecting
Permits and 13 Mining Permits that together cover an area of 184,693.8 acres or 74,742.9 hectares,
and five contiguous Prospecting Licenses covering an area of 57,997 acres or 23,471 hectares. ETK
Inc. (“ETK”), a private company in Guyana, and a wholly owned subsidiary of Sandspring, owns the
rights to the Upper Puruni Property. Sandspring acquired its interest in ETK, and thus its interest in
the Upper Puruni Property, on November 24, 2009.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 17/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 2
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
1.2 Geology and Mineralization
The Toroparu Gold Project is located in northwestern Guyana within the Guiana Shield. The Guiana
Shield encompasses Venezuela, Guyana, Surinam, French Guyana and parts of northern Brazil.
This portion of the Guiana Shield is composed of alternating volcano-sedimentary belts and large
granitoid batholiths of Paleo-Proterozoic age. These supracrustal rocks form the northern part of theGuiana Shield, which is the northern segment of the Amazonian Craton of South America, and a
dismembered portion of the West African Craton. The West African Craton and parts of the Guiana
Shield are well known for hosting gold deposits.
The concession package of Sandspring Resources (1000 km²) is located in the Upper Puruni area,
in between the Cuyuni and Mazaruni rivers, in the north-west part of Guyana. The regional geology
is not well documented due to dense tropical vegetation and thick lateritic/saprolitic weathering
profiles, causing a general lack of bedrock exposure. Sandspring has generated a litho-structural
sketch of the Upper Puruni area, using all available regional data (Project and public data): airborne
magnetics and radiometrics, topographic data, satellite imagery, existing geological maps, and
regional geochemical data.The northeastern half of the Upper Puruni concession is underlain by thick volcano-sedimentary
sequences consisting of alternating mafic, intermediate and to a lesser extent, felsic volcanic flows
and pyroclastics, with intercalated sedimentary successions, generally metapelites and greywackes.
These formations form the Puruni volcano-sedimentary (VS) belt which extends in a northwesterly
direction in between two large plutonic areas, the Aurora batholith located to the northeast of the
concession, and the Putareng batholith underlying most of the southwestern part of the property.
Regional metamorphic grade is greenschist facies and can reach the amphibolite facies in the
vicinity of the granitoid intrusions.
The Putareng batholith corresponds to a calc-alkaline composite intrusive complex, ranging in
composition from granite and tonalite to diorite. Exploration revealed the existence of small, more orless elongated, intra-belt plutons, generally of tonalitic to quartz-dioritic composition. The Toroparu
gold-copper deposit developed along the contact zone of one of these small intrusive bodies.
The Upper Puruni area is marked by sets of NW to WNW and NNW to N-S lineaments. The NW
oriented features seem to constitute typical belt parallel shearing structures, following lithological
contact zones and dominating the regional trend of the belt.
The knowledge of the local geology is mainly based on limited geological mapping of Saprolite in
road and river cuts (alluvial workings), the current Toroparu open pit (entirely in Saprolite) and the
core drilling in the Toroparu deposit area. The dominant lithologies of the Toroparu deposit are
metamorphosed (greenschist facies), often fine grained, acid to mafic volcanics (pyroclastics) and
sediments. The Toroparu gold-copper deposit occurs along the northwestern boundary of a tonaliticto quartz dioritic intrusion, close to the southeastern edge of the pluton.
On a deposit scale, the western part of the Toroparu mineralization system, including the West Zone,
and Main West Zones and the SE satellite deposit are predominantly hosted by intrusive: ne. In the
eastern part of the deposit area (Main East Zone), the mineralization forms an elongated cloud along
a contact zone of a greenschist metamorphic volcanic sequence, draped over a deeper seated
tonalitic intrusive. The different zones of mineralization are interpreted to be separated by WNW and
NNW oriented fault sets.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 18/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 3
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Core logging defines irregular zones of silicification and sericitization/chloritization, with associated
epidote. Carbonate is ubiquitous in most lithologies as small disseminated grains in the
groundmass, and is abundant and associated to quartz in veinlets. Quartz-carbonate veinlets are
common in the gold-copper and gold-only mineralized zones. The veinlets (mm to cm widths)
represent a fine fracturing network that defines the mineralization system
The deposit forms a west-northwestern oriented mineralized corridor, where the gold and copper
mineralization appears to be controlled by a moderately developed, probably dilational type of brittle
fracture/veinlet stockwork.
The mineralization system corresponds to a 2.7 km long and 200 to 400 m wide, WNW oriented
body, consisting of a low grade gold mineralized envelope surrounding several more or less east-
west oriented lenses of higher grade. Mineralization extends to depths of over 400 m.
Exploration and definition core drilling revealed that the larger part of the deposit is comprised of
several more or less east-west oriented lenses:
The Main Eastern lens (Main Zone), containing the larger part of the resource and displaying
in its core zone the highest average Au and Cu grades;
The Main Western lens, marked by lower average gold grades and very low grades of Cu;
and
The SE lens, carrying mainly gold mineralization, forms a near-by satellite body, 1.2 km SE
of the Main Zone.
In the center of the Main East Zone there is clearly a relation between the intensity of the fracturing
and the grade of gold and copper mineralization. The same comment can be made for the SE Zone
mineralization, but involves mainly higher grade gold as copper is nearly absent in this satellite
deposit. Field observations in the historic mining pit, logging of core holes drilled parallel to higher
grade zones (>1.5 g/t), and results of the borehole scanning survey reveal a predominant east-west
fracture set. Drilling is at angle holes with azimuth bearing orthogonal to the east-west fracture/vein
sets.
A significant resource definition drilling program was completed by Sandspring from the end of 2006
to the end of 2012 on the Toroparu deposit, which provides the basis for understanding the Project
geology. Drill core logging allowed for detail understanding of the lithology, structure, and the gold–
copper mineralization in bedrock. Up to the end of 2010 all exploration was focused on the Toroparu
deposit and immediate surrounding areas. Several resource estimates for Toroparu were completed
and presented in NI 43-101 technical reports (P&E, 2009 and 2010).
At the end of the 1st quarter of 2011 an exploration campaign was launched with the main objective
to test the gold potential of the company’s 1,000 km² Upper Puruni Concession. This program
consisted of systematic regional and semi-regional geochemistry sampling, geological mapping,
ground geophysics and reconnaissance exploration drilling. The results of that work are a total of 10
gold anomalies detected, which form a cluster around the Toroparu deposit. The Toroparu gold-
copper deposit was advanced to a scoping study stage with and updated Preliminary Economic
Assessment (PEA) NI 43-101 Technical Report (P&E, 2012) in early March of 2012.
After March of 2012, Sandspring concentrated all efforts on advancing the Toroparu deposit to
prefeasibility study, and the primary focus was deposit definition and in-fill drilling. Sandspring
conducted additional drilling from September 2011 through December 2012, which is included in the
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 19/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 4
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
current updated resource estimate as presented in Section 14 of this report. That additional drilling
was composed of the following:
Post PEA drilling from August 2011 to September 2012, a combination of in-fill and step-out
holes to further define the extents of mineralization: 166 holes for 44,096 m; through hole
TPD-426; and A program of targeted infill drilling to convert Inferred classification mineral resources to
Measured or indicated classification conducted from September through December 2012,
resulted in 48 holes for 12,163 m in both the Main Zone and the Southeast Zone.
Post PEA drilling accounts for an additional 214 drillholes for 56,259 m, or an increase of 38% in
total meters of drilling that are used to update the resources in this report.
The Toroparu gold-copper deposit is sufficiently drill-defined to support feasibility level study.
1.3 Mineral Processing and Metallurgical Testing
Ores tested from the Toroparu deposit are separated into three distinct categories, saprolitic Au ore,
hard rock ores containing Au and recoverable Cu, and hard rock ores containing Au with minor
amounts of Cu. Au recoveries expected from these ores are 98%, 88%, and 95%, respectively. Cu
recovery of the Au-Cu ores is expected to be 91% in a marketable concentrate.
Sandspring initiated several metallurgical testwork programs beginning in 2009 to obtain information
regarding the physical properties of the various ore grade mineralization in the deposit and their
response to comminution, gravity concentration, rougher and cleaner flotation, and cyanide leaching.
Metallurgical testwork and financial analysis tradeoffs were performed to show that processing the
deposit with both flotation and cyanide leaching, depending on Cu content, would provide economic
benefit due to the recovery of a marketable Cu concentrate.
Testwork has shown that both generalized ore designations, Gold Ore with Average Copper (ACO)also described elsewhere in the report as “Au/Cu Ore”, and Gold Ore with Low Copper (LCO), also
described elsewhere in the report as ”Au Ore”, benefit from gravity concentration prior to further
processing. Gravity gold recoveries of 38% were demonstrated for both ACO and LCO ores.
Flotation recoveries achieved from ACO ore were 91% Cu and 42% Au, in addition to gravity gold
recoveries. Testwork shows that both Cu and Au recoveries from LCO ore were acceptable, but the
relative loss in Au recovery versus a cyanide leach was not offset by Cu flotation recovery.
Cyanide leach testwork was conducted to determine the amenability of the ACO and LCO ores. It
was determined that ACO flotation cleaner tailings and LCO gravity tailings leach recoveries were
8% and 58%, respectively, in addition to gravity and flotation recoveries.
Cyanidation testwork was conducted to determine the amenability of the ACO and LCO ores to
cyanide leaching following gravity concentration and flotation. It was determined that ACO flotation
cleaner tailings and LCO gravity tailings leach recoveries were 8% and 58%, respectively, in addition
to gravity and flotation recoveries.
Overall Au recoveries from ACO and LCO ores were determined to be 88% and 95%, respectively.
These recoveries include gravity concentration, flotation, and cyanide leaching.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 20/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 5
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
In addition to the primary hard rock ACO/LCO ores, saprolitic cover ore was also tested for
amenability to gravity concentration, flotation, and cyanide leaching. Testwork showed that gravity
concentration and flotation do not achieve desired recoveries compared to whole ore cyanidation.
Recovery achieved for 72 hour whole ore cyanide leaching was approximately 98% for both RoM
saprolite fines, and coarse saprolite ground to P80 129 µm.
The testwork on ACO Composite samples has shown that the overall gold recovery from gravity
separation and gravity tailings leaching is higher than the case of gravity separation, cleaner flotation
and cleaner tailing leaching. However, due to the lower proportion of copper reporting to the cleaner
tailing leaching stage, the cyanide consumption is lower for this process than in the direct gravity
tailing leaching. This indicates that flotation of gravity tailings plus leaching of the flotation cleaner
tailings would be a better option than leaching of gravity tailings for this type of material.
Similar to the ACO Composite sample testwork, overall gold recovery from direct cyanide leaching of
LCO composites gravity tailings is higher than recovery from cyanide leaching of the rougher
concentrate. Moreover, the cyanide consumption is also lower for the direct cyanide leaching of the
gravity tailings, indicating this method would be more favorable for LCO ore types.
1.4 Mineral Resource Estimate
SRK estimated the Mineral Resources for the Toroparu deposit during January 2013; the estimation
was carried out in compliance with NI 43-101 regulations and CIM standards. The estimate utilized
all drilling available through December 27, 2012. The estimate was prepared by Frank Daviess,
Associate Principal Resource Geologist, SRK Consulting (U.S.), Inc., of Lakewood, Colorado in
accordance with National Instrument 43-101 (NI 43-101). The resources are “in-pit resources”; the
resource model was investigated with a Whittle™ pit optimization to ensure a reasonable stripping
ratio was applied and a reasonable assumption of potential economic extraction could be made.
Table 1.4.1 summarizes the resource for the Main and SE Zones at a 0.30 g/t Au cut-off within the
global optimal pit shells.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 21/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 6
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 1.4.1 Resource Statement @ 0.30 g/t Au cut-off as of March 31, 2013
Resource Classi ficat ion Tonnes Au Au oz Cu Cu(All rock types) (000’s) (g/t) (000’s) % (Mlb)
Main ZoneMeasured 41,542 0.98 1,307 0.109 100
Indicated 185,957 0.87 5,203 0.082 334Measured & Indicated 227,500 0.89 6,510 0.087 434Inferred 127,756 0.74 3,045 0.042 118South East ZoneMeasured 2,905 0.97 91 0.037 2Indicated 9,836 0.93 294 0.035 8Measured & Indicated 12,741 0.94 384 0.036 10Inferred 1,768 0.78 45 0.041 2 Al l ZonesMeasured 44,447 0.98 1,398 0.104 102Indicated 195,793 0.87 5,497 0.079 342Measured & Indicated 240,240 0.89 6,894 0.084 444Inferred 129,525 0.74 3,090 0.042 120
Source: SRK, 2013
1. Mineral resources are inclusive of mineral reserves;2. All resources in the revised mineral resource statement are In-Pit resources reported within an optimized pit shellabove an economic cut-off grade of 0.30 g/t Au. The economic cut-off grade was determined using a gold price ofUS$1,350/oz Au, an average metallurgical recovery of 95.9% for gold, Processing + G&A costs of US$11.49/t, andincludes US$112/oz Au for freight, smelting, refining and royalties. Copper metallurgical recovery used was 91%.Pit slopes used in the pit optimization were 45 degrees, and the mining costs used were US$2.06/t for fresh rock.
3. Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is nocertainty that all or any part of the Mineral Resources estimated will be converted into Mineral Reserves;
4. Mineral Resources are reported in accordance with Canadian Securities Administrators (CSA) National Instrument43-101 (NI 43-101) and have been estimated in conformity with generally accepted Canadian Institute of Mining,Metallurgy and Petroleum (CIM) "Estimation of Mineral Resource and Mineral Reserves Best Practices" guidelines;
5. The grades for Au and Cu were estimated separately, and presented as associated average metal grades at the Aucut-off;
6. Mineral resource tonnage and contained metal have been rounded to reflect the accuracy of the estimate, andnumbers may not add due to rounding;
7. The quantity and grade of reported Inferred resources in this estimation are uncertain in nature and there has beeninsufficient exploration to define these Inferred resources as an Indicated or Measured mineral resource and it is
uncertain if further exploration will result in upgrading them to an Indicated or Measured mineral resource category;and
8. The mineral resource estimate for the Project was calculated by Frank Daviess, MAusIMM, R.M. SME, AssociateResource Geologist of SRK Consulting, Inc. in accordance with the Canadian Securities Administrators NationalInstrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) and generally accepted CanadianInstitute of Mining, Metallurgical and Petroleum “Estimation of Mineral Resource and Mineral Reserves BestPractices” guidelines (“CIM Guidelines”).
1.5 Mineral Reserve Estimate
The estimates of mineral reserves are effective as of March 31, 2013 and are presented in Table
1.5.1. The prefeasibility (PFS) models an open pit mine with a Proven and Probable mineral reserve
containing 4.1 Moz of gold and 211 Mlb of copper, which in contained gold terms represents 60% ofthe 6.9 Moz (in resource-pit shell) Measured and Indicated mineral resource estimate, as disclosed
herein.
Measured and Indicated resources were used for conversion to Proven and Probable reserves within
the optimized PFS pit designs. The mineral reserve (in-pit) cut-off grades (CoGs) used were 0.35 g/t-
Au for saprolite and 0.38 g/t-Au for fresh rock, which correspond to a gold price of US$970/oz Au for
saprolite, and US$1,070/oz Au for fresh rock, respectively.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 22/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 7
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The reserves are contained within the Toroparu pit (Toroparu Pit) and South-East pit (South-East Pit)
and are associated with 468.9 Mt of waste and a life of mine stripping ratio of 3.69:1.
Reserves are valid at the time of estimation and include CoG assumptions made before the final
economic model is published. SRK confirmed the overall Project economics are favorable at the
approximate four-year moving average gold price of $1400/oz Au.
Table 1.5.1: March 31, 2013 Mineral Reserve Estimate
MaterialReserveClassification
Tonnes(000's)
Gold(g/t)
Gold(koz)
Copper(%)
Copper(Mlb)
AuEq(g/t)
AuEq**(koz)
Saprolite Au OreProven 1,621 0.95 50 0.09 *** 0.95 50Probable 3,400 0.90 98 0.10 *** 0.90 98Proven + Probable 5,022 0.91 148 0.10 *** 0.91 148
Fresh Au OreProven 13,976 0.93 419 0.05 *** 0.93 419Probable 56,333 0.88 1,587 0.05 *** 0.88 1,587Proven + Probable 70,309 0.89 2,006 0.05 *** 0.89 2,006
Fresh Au/Cu Ore
Proven 14,183 1.27 581 0.20 64 1.62 740
Probable 37,597 1.14 1,373 0.18 147 1.44 1,740
Proven + Probable 51,780 1.17 1,953 0.18 211 1.49 2,480
All Ore TypesProven 29,780 1.10 1,049 0.13 64 1.26 1,209Probable 97,331 0.98 3,058 0.10 147 1.09 3,425Proven + Probable 127,111 1.00 4,107 0.11 211 1.13 4,634
Source: SRK, 20131. Mineral reserves are based on a gold cut-off-grade (CoG) price of US$1,070/oz. for fresh rock and US$970/oz. for
saprolite. Cash flow Base Case used a gold price of US$1,400/oz. and copper price of US$3.25/lb.;2. Open pit reserves assume complete mine recovery;3. Open pit reserves are diluted (further to dilution inherent in the resource model and assumes selective mining unit of 5 m
x 5 m x 5 m);a. Contained In-situ gold ounces do not include metallurgical recoveries of 96% for gold in saprolite (Oxide), 85% for
gold in Au/Cu fresh rock, 91% for copper in Au/Cu fresh rock, and 96% for gold in Au fresh rock;b. ** AuEq= Gold Equivalent ounce calculated using US$1,403/oz. Au (US$1,394/oz. after refining), US$3.47/lb. Cu
(US$3.17/lb. after NSR deductions), 85.46% gold recovery, 91% copper recovery, Formula 1% Cu = 1.714 g/t-Au);c. *** No copper will be recovered from this ore type (and thus the Gold Equivalent Grade = Gold Grade);
4. Waste tonnes within pit is 468.9 Mt at a strip ratio of 3.69:1 (waste to ore);
5. An open pit CoG of 0.35 g/t-Au saprolite and 0.38 g/t-Au fresh rock was applied to open pit resources constrained by thefinal pit design;
6. Mineral reserve tonnage and contained metal have been rounded to reflect the accuracy of the estimate, and numbersmay not add due to rounding;
7. “(000)” = thousands, “g/t” = gram per metric tonne, “koz” = thousand troy ounces. Ore tonnes are rounded to the nearestone thousand tonnes, gold to nearest 1000 oz Au, gold grade to nearest 0.01 g/t Au, copper rounded to nearest millionpounds.
8. The mineral reserve estimate for the Project was calculated by Fernando P. Rodrigues, BSc, MBA MMSAQP #01405QPof SRK Consulting, Inc. in accordance with the Canadian Securities Administrators National Instrument 43-101 –Standards of Disclosure for Mineral Projects (“NI 43-101”) and generally accepted Canadian Institute of Mining,Metallurgical and Petroleum “Estimation of Mineral Resource and Mineral Reserves Best Practices” guidelines (“CIMGuidelines”); and
9. Reserves Effective Date: March 31, 2013.
1.6 MiningMore accurate resource and geologic models produced over the course of 2011/2012 during the
prefeasibility definition drilling campaigns identified two geographically distinct populations of gold
bearing saprolite and fresh rock ores, distinguishable by their copper sulfide contents, ore with
recoverable copper being defined as “Au/Cu Ore”, also described elsewhere in the report as ACO
(Average Copper Ore) and without recoverable copper content as “Au Ore”, also described
elsewhere in the report as LCO (Low Copper Ore). The mine plan and production schedule defined
in the PFS were optimized for higher metallurgical recovery by processing these ores separately in
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 23/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 24/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 9
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Mining will consist of a conventional open pit operation including drilling and blasting, loading and
hauling. It is planned for a normal hydraulic excavator and haul truck mining fleet to be utilized along
with supporting auxiliary mining equipment (motor graders, water trucks, etc.). For mine planning
purposes and expected fleet numbers, 5 to 22 m3 (bucket size) excavators and 50 to 133 t off-
highway diesel haul trucks have been used.
Drilling and blasting are planned to be performed on 10 m benches in both pits. This matches a
multiple of the block size in the geological block model. Due to the expected selective mining that will
be required for ore mining, loading and hauling are planned to be performed using a half-bench
height for ore, and full bench heights for waste handling.
The Toroparu pit is planned to be developed first, with the process facility to be constructed adjacent
to this pit. This will minimize the ore haulage requirements during the early years of the Project. The
final pit and dump designs are presented in Figure 1.6.2.
The Project plans to use proven technology, with no requirement for untried or untested technology.
Table 1.6.1 summarizes the planned mining production schedule.
Table 1.6.1: Planned Mine Product ion Schedule
Year Saprolite ACOFreshRock
LCOFreshRock
Waste Saprolite ACOFreshRock
LCOFreshRock
ACOFreshRock
LCOFreshRock
Unit kt kt kt kt Au Grade
(g/t) Au Grade
(g/t) Au Grade
(g/t)Cu Grade
(%)Cu Grade
(%)
-3 0 0 0 0 0 0 0 0 0
-2 1,545 20 0 698 1.09 1.15 1.47 0.20% 0.07%
-1 1,466 4,044 353 7,137 0.85 1.09 0.75 0.24% 0.07%
1 402 10,324 2,898 26,375 0.82 1.12 0.81 0.20% 0.06%
2 335 4,981 2,684 31,999 0.69 1.20 0.79 0.21% 0.06%
3 237 4,872 3,056 32,132 0.83 1.26 0.78 0.20% 0.06%
4 478 1,935 5,568 31,371 1.01 1.05 0.89 0.14% 0.05%
5 203 5,628 3,131 31,907 0.80 1.12 0.85 0.18% 0.06%
6 80 2,258 3,560 41,855 0.58 0.95 0.92 0.16% 0.05%
7 7 4,576 3,611 44,385 0.54 1.23 0.92 0.18% 0.05%
8 234 4,985 14,476 37,200 0.81 1.26 0.84 0.14% 0.05%
9 6 324 1,269 45,490 0.65 0.94 0.94 0.17% 0.04%
10 0 1,754 9,957 33,335 0.00 1.19 0.84 0.15% 0.04%
11 29 1,986 10,710 37,428 0.63 1.59 0.99 0.15% 0.05%
12 0 61 2,194 48,125 0.00 1.38 1.01 0.17% 0.02%
13 0 2,319 2,180 17,301 0.00 1.07 0.92 0.19% 0.04%
14 0 1,713 4,661 2,139 0.00 1.28 0.97 0.15% 0.04%
Total 5,022 51,780 70,309 468,875
Source: SRK ACO terminology: Material where the copper content is above 0.09%. -- Material subject to Flotation – a.k.a Au/Cu OreLCO terminology: Material where the copper content is below 0.09%.- Material subject to Cyanide Leaching – a.k.a Au Ore
1.7 Processing Recovery Methods
The Toroparu processing facility will be developed in three phases over the life of mine (LoM). This is
to accommodate for variation in ore types over the production schedule.
The first period is characterized as the preproduction phase. This phase is estimated to consist of
two years, during which the facility will process 3,250 t/d of saprolite through a carbon-in-pulp (CIP)
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 25/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 10
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
leach circuit using a refurbished ball mill already in the possession of Sandspring. The CIP circuit
and downstream process equipment will be designed to expand to the full production rate for
processing a combination of flotation tailings and saprolite during Phase 1.
Phase 1 consists of processing 15,000 t/d of Gold Ore with Average Copper (ACO) via flotation of
gravity tailings with cyanide leaching of the cleaner scavenger flotation tailings via a CIP circuitalongside saprolite. It is estimated that this will occur for the first five years of the mine life. Based on
performed metallurgical testwork recovery by flotation is expected to result in a marketable Cu
concentrate with grade of approximately 21% Cu.
Phase 2 consists of processing 15,000 t/d of Gold Ore with Low Copper (LCO) via CIP leaching and
7,500 t/d of ACO via flotation with CIP leaching of the cleaner scavenger tailing. This phase
continues over the remaining LoM.
A simplified process flow diagram is provided in Figure 1.7.1.
1.8 Tailings Management Area
The Tailings Management Area (TMA) will be located on the northeast side of the Toroparu property,
approximately 8 km from the mine area. This facility will be staged and operated in three
independent cells that will operate separately at different stages of the service life of the facility as
follows:
Cell 1 will operate up to the first quarter of Year 5 of full production;
Cell 2 will operate from the second quarter of Year 7 to second quarter of Year 9; and
Cell 3 will operate from the third quarter of Year 11 to end of the mine life at Year 16.
Detoxed tailings will be discharged into the TMA cells from the crests of the tailings dams, and
supernatant water volumes reclaimed to the plant by a floating pump barge positioned on the decant
ponds of the cells. Excess water volumes will be discharged through spillways into three collectionsponds located adjacent to the cells for monitoring and control before release to the environment.
The design is based on the near surface ground conditions being sufficiently impermeable to prevent
ground contamination without a geosynthetic liner. Fill and compaction of in-situ saprolite was
included in cost estimates. The TMA has a storage capacity of up to 143 Mt.
1.9 Project On-Site Infrastructure
The overall site location, orientation and layout of the on-site infrastructure was based on the criteria
of providing sufficient space for the process and mine facilities, while placing them in close proximity
to the mine pit locations and TMA facility (Figure 1.9.1). Key site infrastructure is located at a safe
elevation above the 100-year storm event boundary limit.
The on-site infrastructure includes the on-site service roads and river crossings; water supply and
treatment; power supply and distribution; mine support facilities; process support facilities; entry
station; and the man camp facilities. Site access roads, which interconnect the various site service
areas are segregated to the maximum extent possible from the mine haul roads.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 26/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 27/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 12
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
vegetation is primarily secondary growth, mixed forest that shows indications of human disturbance.
The mining concession is in a disturbed area consisting mainly of swamp, Morabukea forest, and
mixed forests.
The area is drained by the Puruni River and several tributaries, including the Wynamu River.
Relatively little historical water quality data is available. Surface water quality samples were collectedat two locations in the Puruni River and one location in the Wynamu River during the baseline
sampling in 2007, 2008 and 2010. The majority of the surface water quality results were below the
IFC effluent requirements. Five groundwater monitoring wells have been installed at the site and
samples were collected in 2007, 2008 and 2010. The groundwater levels were lower in the dry
season, which indicates that the water table is recharged by precipitation. Groundwater quality
results indicated slight exceedances of some constituents (iron, pH) and relatively high exceedances
of total suspended solids.
No archaeological resources of interest have been identified at the site.
The fauna documented during the biological survey were fairly common species in Guyana. One
mammal (Jaguar) is listed as globally threatened species by CITES (Convention on InternationalTrade in Endangered Species of Wild Fauna and Flora), which is an international trade agreement
regarding wild animals and plants. Up to 160 bird species were noted during any one survey, and
migratory birds have been recorded. There were 52 individual fish species recorded. There were 32
herpetofauna species recorded and 24 Arthropod orders recorded. No locally rare, threatened or
endangered species were recorded, however a number of species were identified as having status
under CITES.
Mining Wastes
Tailings and waste rock will be produced by the mining operations, plus there will be a Low Grade
Ore (LGO) stockpile. Metallurgical testing was done on three main ore types (saprolite, ACO and
LCO). The metallurgical tailings generated from each of the ore types, the dominant bedrock
lithologies in the waste rock and the LGO were tested for their Acid Rock Drainage/Metal Leaching
(ARD/ML) potential during geochemical characterization studies conducted by KCB (2013). The
geochemical testing was based on Canadian and industry guidance documents for the prediction of
ARD/ML. In the absence of specific Guyanese water quality guidelines, the water quality guidelines
applicable to British Columbia and Canada were applied as a screening tool to assess laboratory
leachate results.
Lithologies identified as potential waste rock included acid intrusive; fragmental mafic volcanic;
granodiorite; mixed facies; saprolite; and undifferentiated intermediate volcanics. The waste rock,
metallurgical tailings and LGO samples were analyzed for mineralogical analysis, solid-phase
elemental analysis and Acid-base Accounting. In addition, the waste rock samples were analyzed forShake Flask Extraction (SFE) and Net Acid Generation (NAG) tests. The metallurgical tailings
samples were also subjected to supernatant aging tests.
The majority of waste rock lithologies and LGO samples contained very low sulfide-sulfur
concentrations, which indicates negligible ARD risk. The waste rock lithologies and LGO were
classified as not-Potentially Acid Generating (N-PAG), with the exception of the saprolite samples.
The saprolite samples were predominantly Acid Generating (AG) and PAG, with a low amount of
available Neutralization Potential (NP). The saprolite waste is approximately 15% of the total waste.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 28/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 13
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
A standard operating procedure will be developed to encapsulate the saprolite waste within the fresh
rock waste rock facility.
All metallurgical tailings samples contained low to negligible sulfide-sulfur concentrations and were
classified as N-PAG. It was also noted that the saprolite metallurgical tailings contained little to no
reactive carbonate minerals, which indicates that the NP present in the saprolite metallurgical tailingsis related to the lime added during the metallurgical processing.
The leachate extraction tests results indicated that waste rock and LGO may develop alkaline
drainage with elevated concentrations of aluminum, selenium, chromium and, to a lesser extent,
elevated concentrations of copper and phosphorus based on freshwater aquatic life guidance. The
supernatant aging test results for the metallurgical tailings indicated that alkaline drainage with
elevated concentrations of aluminum, selenium, chromium, arsenic, cobalt, copper, iron,
molybdenum, WAD cyanide and sulfate may develop. Iron and WAD cyanide concentrations in the
LCO tailings supernatant were also elevated. Although the metallurgical tailings leachate extraction
test results indicated elevated concentrations that may be soluble and mobile under laboratory test
conditions, the results do not imply that they will be elevated to levels above these guidelines undersite-specific field conditions, rather they identify elements that are prone to leaching. The tailings
management area (TMA), will receive a combination of precipitation, water treatment plant brine, and
supernatant from the tailings slurry. The TMA water quality will be influenced by contributions from all
these sources. Natural attenuation of these elements will occur primarily through dilution from high
precipitation, which is reported to average about 2.6 m annually at the Toroparu Project site.
Additional geochemical testing would be required to assess future site-specific field conditions;
however the current status of the geochemistry program is in line with a PFS project.
Environmental Impact Analysis
Potential environmental impacts were evaluated as part of the ESIA preparation. The most
significant associated impacts and associated planned mitigation strategies are as follows:
• Soil erosion and sedimentation from disturbed areas will be minimized or avoided by
implementation of BMPs to be described in an Erosion and Sediment Control Plan;
• Emissions of fugitive dust and combustion products will be mitigated by scheduling land-
clearing activities to less windy days, limiting vehicle speeds and employing dust
suppression techniques;
• Accidental spills of fuels, oils and grease will be minimized as described in a spill Prevention
and Contingency Plan; and
• Impacts to wildlife will be mitigated by minimizing the disturbance areas and by maintaining
wildlife corridors through cleared areas.
An Environmental Management Plan and a monitoring program have been developed to mitigate
and monitor changes to the both the physical and socio-cultural environments.
Social or Community Impact
There are no formal or established communities or settlements in the immediate vicinity of the mine
site. Since there are no communities in the area of direct influence of the Project, the social baseline
was developed based on a broader area of indirect influence, such as the communities which could
serve as entry points to the mine site and vulnerable communities that could supply employees.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 29/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 30/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 15
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The total estimated initial cost to design and build the Toroparu Project identified in this report is
US$464 million. A summary overview of the estimate by area is presented in Table 1.13.1.
Table 1.13.1: Summary of Capital Costs by Area
PFS Capital Cost Estimates
(US$ Millions) Scope
Initial
Capital(Pre-Prod)
Expansion and
SustainingCapital
LoM
Capital
Fresh Rock Pre-Stripping SRK $24 $0 $24Mine Site Preparation / Roads SRK $2 $0 $2Mining Equipment SRK $69 $168 $237Milling Circuit Tt $75 $0 $75Leaching Circuit Tt $36 $0 $36Flotation Circuit Tt $24 $0 $24Process Plant Infrastructure Tt $6 $0 $6Plant Expansion Tt $0 $50 $50Tailings Storage Facility Tt/KCB $16 $63 $80On-Site Infrastructure Tt $11 $11 $22Power Generation Tt $27 $0 $27Water Management Tt $9 $0 $9
Camp and Ancillary Buildings Tt $25 $0 $25Port and Logistics FMG $9 $0 $9 Access Road Upgrades FMG $33 $0 $33Construction Indirects (incl. EPCM) Tt $79 $0 $79Owner's Costs (Incl. Closure) Sandspring $20 $15 $35
Sub-Total Project Capital Costs $464 $307 $771Mining Contingencies (Site Prep + Equip) SRK $4 $8 $12Process and Infrastructure Contingencies Tt/KCB/FMG $32 $0 $32Owner’s Costs Contingencies Sandspring $2 $4 $6
Total Contingencies All $37 $13 $50
Total Capital Requirement All $501 $319 $821
Contribution from Saprolite Au OreMargin
All ($37) $0 ($37)
Total Project Costs w/ Contingencies All $464 $319 $784
The aggregate capital estimate is considered to be within a +30% / -25% weighted average accuracy
of actual costs. Base pricing will be in Q1 2013 United States dollars, with no allowances for inflation
or escalation beyond that time.
The contingency cost is based on the total direct and/or indirect costs and are included to account for
unanticipated costs within the scope of the estimate. The contingency percentage allowances vary
and are individually assessed based on the accuracy of the quantity measurement, type and scope
of work, and price information for the capital cost estimate.
Operating Costs
The PFS estimate is based on independent reputable vendor quotations and where not available,
first principal calculations completed by the Consultants. Each Consultant used their standard
estimating system to calculate its respective operating costs for the Project.
Operating costs have been prepared in Q4 2012 US dollars and exclude:
Contingency;
Escalation;
Taxes (VAT); and
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 31/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 16
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Import Duties.
Imported equipment, materials, and operating supplies are not subject to Taxes (VAT), import or
other duties as per the Mineral Development Agreement.
The operating cost estimates have been assembled by area and component, based upon estimated
staffing levels, consumables and expenditures according to the mine and process design. Life-of
mine (LoM) operating costs are shown in Table 1.13.2 (rounded to nearest US$1,000).
Table 1.13.2: Operating Cost Li fe of Mine, US$000s
Area Labor (US$000s) Expenses (US$000s) US$/t-Mined US$/t-Mi ll
Mine 159,656 946,003 1.86 8.70
Processing 22,238 1,313,509 n/a 10.51
G&A 92,515 81,306 n/a 1.37
Total Operating 274,408 2,340,818 n/a 20.57
1.14 Economic Analysis A discounted cash flow model was created to evaluate the Toroparu Project assuming the Project is
100% equity financed. All revenues and costs are expressed in US dollars.
Mining cost estimates were provided by SRK and process costs were provided by Tt. Offsite
infrastructure costs were provided by FMG, and Owner’s cost by Sandspring. Additional costs such
as refining, royalties and administrative costs provided by SSP were subtracted from the revenue to
calculate an estimated cash operating margin.
The Prefeasibility makes use of Proven and Probable reserves only.
An income tax rate of 30% is used based on the rate defined in the Mineral Agreement that governs
the Project. The resulting cash flow in each year of the Project life is discounted back to January ofYear -3 to determine the estimated discounted cash flow at a 5%, 8% and 10% discount rate. Using
this same data, the estimated internal rate of return and the undiscounted cash flow were also
determined.
The major input parameters to the model include gold and copper prices, sustaining capital,
operating costs, mining rates, and estimated taxes and royalties. Additionally, several minor
assumptions throughout the model such as working capital, environmental accruals and depreciation
rates affect the estimated Project economics to a lesser degree.
SRK and Sandspring prepared a detailed financial model (the Financial Model) estimating cash flows
by year for the forecast mine life.
The model was also based on the following Project basic schedule:
Construction period: 3 years, two of which are also the saprolite preproduction years; and
Production period: 16 years.
Start-up – For the purpose of the model, the plant is estimated to commence the processing of
saprolite ore on January 1st of Year -2 and will continue for two years (Years -2 and -1). Fresh rock
starts to be processed on January 1st of Year 1.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 32/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 17
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Working capital – Working capital was included in the model. This estimate was considered as 20%
of all operating costs for each period.
Escalation – The components of the economic model were based on the following:
Base capital pricing for the Project is in Q1 2013 United States dollars, with no allowances
for inflation or escalation beyond that time;
Equipment quotes from vendors were obtained in Q4 2012; and
Operating costs were prepared in Q4 2012 terms.
All financial results are based in Q4 2012 and Q1 2013 dollars and no escalation has been assumed
for the metal prices or cost inputs.
Closure Costs – Estimated closure costs for the dismantling of the plant and infrastructure, and for
long-term water treatment, were estimated at US$16 million, including contingencies. For the
purposes of the financial model, these costs were incurred over a period of one year, following the
processing of the last ore through the mill. No credit was provided in the model for the potential
salvage value of equipment.Table 1.14.1 presents further details of the economic results. Payback from plant start of operations
(January of Year 1) is 2.6 years. Figure 1.14.1 shows the after-tax sensitivities to capital costs,
operating costs and metal prices at the 5% discount rate.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 33/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 18
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 1.14.1: Project Evaluation Economic Results
Descript ion Value (US$) Units
Market PricesGold $1,400 /Au-ozCopper $3.25 /Cu-lb
Estimate of Cash Flow (all values in $000s)Gross Income $/Au-ozPayable Gold (Doré+Concentrate) $5,190,263 $1,400.00Payable Copper $593,609 $160.00Gross Income $5,783,872
$/Au-ozTreatment Charges ($39,353) ($10.61)Refining Charges ($18,937) ($5.11)Predicted Penalties ($2,253) ($0.61)Freight Insurance Cost ($71,641) ($19.32)Gross Revenue $5,651,687
$/Au-ozGuyana Au Royalty ($413,937) ($111.65)Guyana Cu Royalty ($7,162) ($1.93)
One Time Royalty to Surface Owner ($20,000) ($5.39)Net Revenue $5,210,588Operating Costs $/Au-ozMining Cost ($1,105,659) ($298.24)Processing Cost ($1,335,747) ($360.30)Site G&A Cost ($173,821) ($46.89)Total Operating ($2,615,227)$/t-ore ($20.57)Cash Cost ($/Au-oz) ($700)Operating Margin (EBITDA) $2,595,362Initial Capital ($501,192)Total Capital ($820,651)Income Tax ($506,310)Cash Flow Available for Debt Service $1,268,400
Pre-Tax IRR 27.19%Pre-Tax Present Value 0% $1,774,710Pre-Tax Present Value 5% $991,516Pre-Tax Present Value 8% $702,064
After -Tax IRR 23.14% After -Tax Present Value 5% $690,869 After -Tax Present Value 8% $476,171 After -Tax Present Value 10% $367,345
1.15 Conclusions and Recommendations
Mineral Resources
The mineral resource within the material encompassed by the PFS design pit has been sufficiently
sampled and delineated to achieve a confidence classification (Measured and Indicated) which is
adequate for mine planning purposes at the feasibility study level.
Mineral Reserves and Mining Methods
Through the process of pit optimization, fleet estimation, mine design, production scheduling and
economic modeling, the Toroparu open pit operations have been sized and estimated appropriately
at prefeasibility level. SRK has estimated a mining cost of US$1.86/t mined for in-situ and re-handled
material over the LoM. Combined with a ramp-up to 52 Mt/y, the benefit of high production rates,
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 34/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 19
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
grade bin schedule and support from two pit operations, SRK is of the opinion the costs estimated
are reasonable at the present time (2013).
Open pit initial mine capital is estimated at US$74.7 million (site preparation and equipment including
contingency) with an addition US$176.5 million in sustaining capital (including contingency), which
includes purchase of new equipment.
Additional mining studies required at a feasibility level of design for the Project include:
Incorporate additional geotechnical design data into the SE Pit design;
Feasibility level pit designs including dewatering structures;
Improved estimates of groundwater in-flow from local structures into the pit;
Assessment of a condemnation drilling program to confirm the locations of the low grade ore
stockpile, primary crusher and waste dumps;
Development of a feasibility level mine production schedule including monthly periods to
start, and completing the LoM schedule in quarterly periods to determine continuous ore
exposure; and
Assessment of an expanded articulated dump truck (ADT) fleet to mine part of the saprolite
waste and ore throughout most of the LoM mine production schedule.
Metallurgy Process and Recovery
The testwork of ACO Composite samples has shown that the overall gold recovery from gravity
separation and gravity tailings leaching is higher than the case of gravity separation, cleaner flotation
and cleaner tailing leaching. However, due to the lower proportion of cyanide soluble copper
reporting to the cleaner tailing leaching stage, the cyanide consumption is lower in the flotation
process than direct gravity tailing leaching. The lower reagent costs and the benefit of the copper as
a by-product credit indicates that flotation plus leaching of the flotation cleaner tailings would be a
better option for this type of material.
Similar to the ACO Composite, overall gold recovery from direct cyanide leaching of LCO composites
gravity tailings is higher than the cyanide leaching of the rougher concentrate. Moreover, the cyanide
consumption is also lower for the direct cyanide leaching of the gravity tailings than leaching of
concentrate, indicating leaching of gravity tailings is more favorable for LCO ore types when
compared to flotation of LCO ore.
Testwork on the ACO and LCO composites has also shown that a significant amount of copper is
loaded onto the carbon following cyanide leaching. To limit the amount of copper loading on the
carbon, the initial cyanide concentration may need to be increased. The higher cyanide
concentration will likely increase the extraction of copper and we recommend further optimization
testing to further define the design parameters. It is also recommended that a Gravity RecoverableGold (GRG) test be conducted to further define the effect of grind size on the recovery of gold.
Flotation testwork conducted during this program focused on evaluating the effect of grind size on
recovery, and additional study will be required to finalize a flotation circuit flowsheet. The results from
the locked cycle test of the ACO Master Composite indicated that there is a build-up of non-sulfide
gangue in the cleaning circuit. It is recommended that further flotation testwork be conducted to
better understand the effect of cleaner circuit flowsheet and use of gangue depressant, CMC, and
other reagents and flotation flowsheets to potentially improve the process.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 35/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 20
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
We recommend additional variability testing with regard to gravity separation, copper flotation and
cyanide leaching on the LCO composite. The testing should identify the gold response in variation to
head grade.
A pilot scale HPGR test, in which 2 tons of material is tested, is recommended to properly size the
HPGR unit, as the relevant testwork to date only provides preliminary sizing information on a scopinglevel. This should be performed in conjunction with variability comminution testing to provide better
selection of ball mills.
Due to the number of thickeners present in the proposed flowsheet, additional thickening tests are
recommended to properly size the thickeners. These tests should evaluate the following:
ACO rougher flotation tailings;
A mixture of the CIP tailings comprised of saprolite and ACO cleaner flotation tailings;
LCO whole ore material; and
A mixture of the CIP tailings comprised of LCO material and ACO cleaner flotation tailings.
In the event that variability gravity/float/and leach testing of the ACO or LCO material indicates analternative process flowsheet, then thickening tests should be expanded to reflect such a change.
This is especially relevant if an LCO cleaner flotation process is considered to better define the
impact of finer particles due to the regrind circuit which will impact settling behavior.
If sufficient sample is produced, thickening and filtration testing of the copper concentrate should be
performed as selection and sizing of concentrate dewatering equipment is currently assumed due to
the absence of any related testwork.
Lastly, additional cyanide destruction (CND) testing should be performed to confirm earlier findings.
In addition, should any of the variability testing of the ACO or LCO material yield a flowsheet
significantly different than what is currently proposed then CND testing should be expanded to
included such changes.
On-Site Infrastructure
Considering that the Project is at prefeasibility level, the following work to progress the Project to the
next level is recommended.
Perform condemnation drilling at the proposed plant site and man camp site;
Perform a geotechnical site investigation that includes test pits, drillholes and seismic
refraction surveys to support foundation design and engineering;
Perform a feasibility study design on the on-site infrastructure;
Confirm water supply source, quality and quantity requirements; and
Confirm wastewater treatment, discharge point, quality and quantity requirements.Tailings Management Area
The geotechnical conditions of the tailings site have been assumed from the geology information
previously described and from the results of the investigation program carried out by KCB (2012) at
the location of the tailings site defined in the PEA. A specific site investigation program for the
tailings site should therefore be carried out for the new location defined in this study during feasibility
engineering of the Project.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 36/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 21
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Off-Site Infrastructure
Considering the location of the Toroparu Mine, off-site infrastructure will play a key role in the
operation and success of the Project. The presence of an existing roadway from the Mazaruni River
to the mine is advantageous, and upgrades to the roadway will ensure safe, reliable transport of
cargo to and from the mine. Overall operation and maintenance of the roadway is currentlyadministered by the GoG via a contract with ETK and local contractors. After upgrade of the roadway
by Sandspring-ETK as contemplated in this technical report, the GoG will bear the full operating
costs associated with the Toroparu Mine Road.
Construction of the port facility at Pine Tree Landing will create a secure shipping point for mine
equipment, bulk mine supplies and concentrate, and will serve as a base camp for mine supply chain
transport vehicles.
Detailed engineering design will be required to prepare construction documents and to finalize
construction cost estimates for the port facility and roadway upgrades.
Environment, Permits, Licenses and Authorizations
The Project area has been historically impacted by mining activities, logging, and hunting. With only
a few exceptions, species classified as rare, threatened or endangered have not been observed in
the Project area. No indigenous hunting activity or cultural resources were identified within the
proposed mining area. The water quality baseline sampling has not included specific sampling
events to establish a baseline characterization trend with seasonal variability. SRK recommends that
quarterly sampling be re-established to coincide with the variation in the wet and dry seasons. SRK
recommends that the sampling methodology and water construction and development procedures be
further reviewed due to some abnormalities in the water sampling results. It is recommended that
monitoring at the weather station be continued on a monthly basis.
Results of the geochemical testing of the waste rock by KCB showed that the waste rock lithologiesand LGO samples contained very low sulfide-sulfur concentrations, indicating low risk of PAG,
except for the saprolite. The saprolite and transition zone samples contained very low NP, whereas
the waste rock and LGO had NP related to reactive carbonate minerals. The saprolite samples were
classified primarily as acid-generating and PAG, whereas the other waste rock and LGO samples
were classified as non-PAG.
The tailings samples contained low to negligible sulfide-sulfur concentrations and were classified as
non-PAG. The majority of the NP of the tailings was associated with the reactive carbonate minerals
and/or lime added during the metallurgical testing. The saprolite tailings contained little to no reactive
carbonate minerals, and thus the NP present in the saprolite tailings was related to the lime added
during the metallurgical process.
Leachate testing indicated that the waste rock may develop alkaline drainage with the possibility of
elevated concentrations of aluminum, selenium, chromium and, to a lesser extent, copper and
phosphorus. The tailings could develop alkaline drainage with the possibility of elevated
concentrations of aluminum, selenium, chromium, arsenic, cobalt, copper, iron, molybdenum, WAD
cyanide and sulfate. The geochemistry program should be advanced to a more detailed program that
will include predictions of water quality associated with the mining wastes run-off and discharges.
Water quality management strategies are needed for the tailings pond. Further static and kinetic
testing is recommended.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 37/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 22
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Additional geochemical studies that are recommended by KCB include humidity cell testing and/or
field lysimeters or leach barrels to evaluate alkaline metal leaching rates, and follow-up predictive
water quality modeling for waste rock run-off and seepage, and TMA pond discharge water quality.
For the metallurgical tailings, KCB recommended that laboratory kinetic tests be initiated to assess
the TMA pond and porewater quality. An ESIA was prepared and submitted to the Guyana EPA,
which subsequently issued an environmental permit for mining and processing. A variety of
compliance items are required as part of the environmental permit. The application for and receipt of
the Mining License will be required prior to commencing full-scale operations
Although additional studies are recommended to further develop mining waste management
strategies, there are no known environmental issues that could materially impact Sandspring’s ability
to extract the mineral resources or reserves at the site. Preliminary mitigation strategies have been
developed to reduce environmental impacts to meet regulatory requirements and the specifications
of the environmental permit.
Community Relations and Social Responsib ility
There are no formal or established communities in the immediate vicinity of the site. The Project isnot expected to generate many direct socio-economic impacts. A Social Management Plan has been
proposed to mitigate the socio-cultural impacts identified in the ESIA. It is recommended that
consultation with the community be continued. The Social Management Plan proposed in the ESIA
should be prepared and implemented as required under the environmental permit.
Economic Analysis
A discounted cash flow model was created to evaluate the Toroparu Project assuming the Project is
100% equity financed. All revenues and costs are expressed in US dollars.
An income tax rate of 30% has assumed. The resulting cash flow in each year of the Project life was
discounted back to January of Year -3 to determine the estimated discounted cash flow. Using thissame data, the estimated internal rate of return and the undiscounted cash flow were also
determined.
Using a gold price of US$1,400/oz and a copper price of US$3.25/lb, results of the base case
analysis indicate that the Toroparu Project has a potential after-tax internal rate of return of 23% and
a present value of approximately US$690 million, based on a 5% discount rate.
The base case payback period is estimated at 2.6 years, including sustaining capital, from the start
of the production period (from the start of Year 1).
These positive results indicate that the Project should be advanced to a Feasibility Study.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 38/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 39/340
TOROPARU GOLD PROJECT
TOROPARU MINE SITE
04/26/13 ISSUED FOR PRE-FEASIBILITY DEN PC PC
114-311317-DWG-C-101
04/2013
DEN
A
ASSHOWN
LEGEND
EXISTING MAJOR CONTOUR
EXISTING MINOR CONTOUR
PROPOSED MAJOR CONTOU
PROPOSED MINOR CONTOU
EXISTING ROAD
EXISTING RIVER
EXISTING FLOODPLAIN BOU
PROPOSED FLOODPLAIN BO
PROPOSED ROADS
PROPOSED CHANNEL
PROPOSED LEVEE
HAUL ROAD
PROPOSED PAD
PROPOSED POND
METER
125 125 250
1:1
0
DRAWING DESCRIPTION:
PROJECT NAME:
DRAWING NO:
AUTHORIZED BY:
DESIGNED BY: REVIEWED BY:PREPARED BY:
SCALE:
SEALPERMIT STAMPSUB CONSULTANT(S) : CLIENT:
NO. DESCRIPTIONDATE
REVISIONS/ISSUE DRAFTING
PREPAREDREVIEW DESIGN AUTHORIZE
ENGINEERING
NO. DESCRIPTION
REFERENCEDRAWINGS
DATE:
3D MODEL REF No:
NOTE:
MINE PLAN 18 ULTIMATE PIT BOUNDARY, SRK AP
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 40/340
Toroparu Gold Project,
Guyana
Figure 1.6.2
Mine Plan Progress MapsYear 14 End, Ultimate PitSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 41/340
JAW
CRUSHER
SECONDARY
CONE
CRUSHER
DUMP
TRUCK
P
TCIP TANK
NO.1
TAILING MANAGEMENT AREA
ACID WASH
TANK
ELECTROWINING CELLSKILN
TO CARBON FINES
RECOVERY
PROCESS
WATER TO
DISTRIBUTION
DETOXIFICATION
FRONT END
LOADER
SAPROLITE
SCREEN
FLOTATION
STOCKPILE
LEACH
STOCKPILE
HPGR
SCREEN
ELUTION
COLUMNS
SCREEN
GRAVITY
CONCENTR
BALL MILL
HPGROVER SIZE
BALL MILL
AUTHORIZED BY:
DESIGNED BY:SEALPERMIT STAMPSUB CONSULTANT(S) :
NO. DESCRIPTIONDATE
REVISIONS/ISSUE DRAFTING
PREPARE D RE VIE W DE SIGN AU TH ORIZ E
ENGINEERING
NO. DESCRIPTION
REFERENCE DRAWINGS
A 03/26/13 ISSUED FOR INTERNAL REVIEW R.P. R.P.
B 04/02/13 ISSUED FOR CLIENT REVIEW R.P. R.G.
0 05/07/13 ISSUED FOR PRE-FEASIBILITY STUDY R.G. P.C.
SCREENSCREEN
SCREEN
PUMP BOX
TANK
PUMP BOX
CONVEYOR
SCREEN
CONVEYOR
CONVEYOR
CIP TANK
NO.2
CIP TANK
NO.3
CIP TANK
NO.4
CIP TANK
NO.5
TRAIN A & B
CONVEYOR CONVEYOR
HYDROCYCLONESHYDROCYCLONES
CONVEYOR
CONVEYOR
HOPPER
CONVEYOR
REBA
REFINERY
TAILINGS
THICKENERS
1 & 2
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 42/340
TOROPARU GOLD PROJECT
TOROPARU MINE OVERAL
04/26/13 ISSUED FOR PRE-FEASIBILITY DEN PC PC
114-311317-DWG-C-100
04/2013
DEN
A
ASSHOWN
LEGEND
EXISTING MAJOR CONTOUR
EXISTING MINOR CONTOUR
PROPOSED MAJOR CONTOU
PROPOSED MINOR CONTOU
EXISTING ROAD
EXISTING RIVER
EXISTING FLOODPLAIN BOU
PROPOSED FLOODPLAIN BO
PROPOSED ROADS
PROPOSED CHANNEL
PROPOSED LEVEE
HAUL ROAD
PROPOSED PAD
PROPOSED POND
METER
300 300 600
1:3
0
DRAWING DESCRIPTION:
PROJECT NAME:
DRAWING NO:
AUTHORIZED BY:
DESIGNED BY: REVIEWED BY:PREPARED BY:
SCALE:
SEALPERMIT STAMPSUB CONSULTANT(S) : CLIENT:
NO. DESCRIPTIONDATE
REVISIONS/ISSUE DRAFTING
PREPAREDREVIEW DESIGN AUTHORIZE
ENGINEERING
NO. DESCRIPTION
REFERENCEDRAWINGS
DATE:
3D MODEL REF No:
NOTE:
1. MINE PLAN 18 ULTIMATE PIT BOUNDARY, SRK APRIL 15, 201
2. TMA FACILITY BOUNDARY, KCB MARCH 18, 2013.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 43/340
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
80% 90% 100% 110% 120%
NPV 5% Sensivity ($000s)
Capital Costs
Operating Costs
Revenue
Toroparu Gold Project,
Guyana
Figure 1.14.1
NPV Sensit ivitySource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 44/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 29
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_043_MLM.docx May 24, 2013
2 Introduction
2.1 Terms of Reference and Purpose of the Report
This report is as a National Instrument 43-101 (NI 43-101) Technical Report on the PrefeasibilityStudy of the Toroparu Gold Project (Toroparu or Project) prepared for Sandspring Resources Ltd.
(Sandspring) by SRK Consulting (U.S.), Inc. (SRK), Tetra Tech (Tt), Klohn Crippen Berger (KCB),
Knight Piésold (KP), and FMG, Inc. (FMG), (collectively the Consultants). The quality of information,
conclusions, and estimates contained herein is consistent with the level of effort involved in SRK’s
services, based on: i) information available at the time of preparation, ii) data supplied by outside
sources, and iii) the assumptions, conditions, and qualifications set forth in this report. This report is
intended for use by Sandspring subject to the terms and conditions of its contract with SRK and
relevant securities legislation. The contract permits Sandspring to file this report as a Technical
Report with Canadian securities regulatory authorities pursuant to NI 43-101, Standards of
Disclosure for Mineral Projects. Except for the purposes legislated under provincial securities law,
any other uses of this report by any third party is at that party’s sole risk. The responsibility for thisdisclosure remains with Sandspring. The user of this document should ensure that this is the most
recent Technical Report for the property as it is not valid if a new Technical Report has been issued.
This report provides mineral resource and mineral reserve estimates, and a classification of
resources and reserves in accordance with the Canadian Institute of Mining, Metallurgy and
Petroleum Standards on Mineral Resources and Reserves: Definitions and Guidelines, November
27, 2010 (CIM).
2.2 Qualifications of Consultants
The Consultants preparing this technical report are specialists in the fields of geology, exploration,
mineral resource and mineral reserve estimation and classification, underground mining,
geotechnical, environmental, permitting, metallurgical testing, mineral processing, processing design,
capital and operating cost estimation, and mineral economics.
None of the Consultants or any associates employed in the preparation of this report has any
beneficial interest in Sandspring. The Consultants are not insiders, associates, or affiliates of
Sandspring. The results of this Technical Report are not dependent upon any prior agreements
concerning the conclusions to be reached, nor are there any undisclosed understandings concerning
any future business dealings between Sandspring and the Consultants. The Consultants are being
paid a fee for their work in accordance with normal professional consulting practice.
The following individuals, by virtue of their education, experience and professional association, are
considered Qualified Persons (QP) as defined in the NI 43-101 standard, for this report, and are
members in good standing of appropriate professional institutions. The QP’s are responsible for
specific sections as follows:
Alex Fisher, B.Sc. Geological Engineering, P.E. is the QP responsible for the off-site
infrastructure (road and port) Sections 18.3, 21.2.3, 21.3.4, and portions of Sections 1, 25
and 26 summarized therefrom, of this Technical Report. Mr. Fisher conducted an
investigation of the road and port sites on December 2 through 6, 2011;
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 45/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 46/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 31
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_043_MLM.docx May 24, 2013
2.3 Sources of Information
This report is based, in part, on internal company technical reports and maps, published government
reports, company letters and memoranda, and public information as listed in the "References"
section of this report. Several sections from reports authored by other consultants have been directly
quoted in this report, and are so indicated in the appropriate sections. SRK has not conducteddetailed land status evaluations, and has relied upon previous qualified reports, public documents
and statements by Sandspring regarding property status and legal title to the Project.
2.4 Units of Measure
Unless otherwise stated all units used in this report are metric. Gold and silver assay values are
reported in grams per tonne (g/t) unless ounces per ton (oz/ton) are specifically stated. Base metal
assay values are given in percent (%) or in parts per million (ppm). The US$ is used throughout this
report unless otherwise noted.
2.5 Glossary and Abbreviated Terms
2.5.1 Mineral Resources
The mineral resources and mineral reserves have been classified according to the “CIM Standards
on Mineral Resources and Reserves: Definitions and Guidelines” dated November 27, 2010 (CIM).
Accordingly, the Resources have been classified as Measured, Indicated or Inferred, the Reserves
have been classified as Proven, and Probable based on the Measured and Indicated Resources as
defined below.
A Mineral Resource is a concentration or occurrence of natural, solid, inorganic or fossilized organic
material in or on the Earth’s crust in such form and quantity and of such a grade or quality that it has
reasonable prospects for economic extraction. The location, quantity, grade, geologicalcharacteristics and continuity of a Mineral Resource are known, estimated or interpreted from
specific geological evidence and knowledge.
An ‘Inferred Mineral Resource’ is that part of a Mineral Resource for which quantity and grade or
quality can be estimated on the basis of geological evidence and limited sampling and reasonably
assumed, but not verified, geological and grade continuity. The estimate is based on limited
information and sampling gathered through appropriate techniques from locations such as outcrops,
trenches, pits, workings and drillholes.
An ‘Indicated Mineral Resource’ is that part of a Mineral Resource for which quantity, grade or
quality, densities, shape and physical characteristics can be estimated with a level of confidence
sufficient to allow the appropriate application of technical and economic parameters, to support mineplanning and evaluation of the economic viability of the deposit. The estimate is based on detailed
and reliable exploration and testing information gathered through appropriate techniques from
locations such as outcrops, trenches, pits, workings and drillholes that are spaced closely enough for
geological and grade continuity to be reasonably assumed.
A ‘Measured Mineral Resource’ is that part of a Mineral Resource for which quantity, grade or
quality, densities, shape, physical characteristics are so well established that they can be estimated
with confidence sufficient to allow the appropriate application of technical and economic parameters,
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 47/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 32
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_043_MLM.docx May 24, 2013
to support production planning and evaluation of the economic viability of the deposit. The estimate
is based on detailed and reliable exploration, sampling and testing information gathered through
appropriate techniques from locations such as outcrops, trenches, pits, workings and drillholes that
are spaced closely enough to confirm both geological and grade continuity.
2.5.2 Mineral Reserves
A Mineral Reserve is the economically mineable part of a Measured or Indicated Mineral Resource
demonstrated by at least a preliminary feasibility study. This study must include adequate
information on mining, processing, metallurgical, economic and other relevant factors that
demonstrate, at the time of reporting, that economic extraction can be justified. A Mineral Reserve
includes diluting materials and allowances for losses that may occur when the material is mined.
A ‘Probable Mineral Reserve’ is the economically mineable part of an Indicated, and in some
circumstances a Measured Mineral Resource demonstrated by at least a preliminary feasibility study.
This study must include adequate information on mining, processing, metallurgical, economic, and
other relevant factors that demonstrate, at the time of reporting, that economic extraction can be
justified.
A ‘Proven Mineral Reserve’ is the economically mineable part of a Measured Mineral Resource
demonstrated by at least a preliminary feasibility study. This study must include adequate
information on mining, processing, metallurgical, economic, and other relevant factors that
demonstrate, at the time of reporting, that economic extraction is justified.
2.5.3 Definit ion of Terms
The following general mining terms may be used in this report.
Table 2.5.3.1: Definiti on of Terms
Term Definition Assay The chemical analysis of mineral samples to determine the metal content.
Capital Expenditure All other expenditures not classified as operating costs.
Composite Combining more than one sample result to give an average result over a largerdistance.
Concentrate A metal-rich product resulting from a mineral enrichment process such as gravityconcentration or flotation, in which most of the desired mineral has been separatedfrom the waste material in the ore.
Crushing Initial process of reducing ore particle size to render it more amenable for furtherprocessing.
Cut-off Grade The grade of mineralized rock, which determines as to whether or not it is economicto recover its gold content by further concentration.
Dilution Waste, which is unavoidably mined with ore.
Dip Angle of inclination of a geological feature/rock from the horizontal.
Fault The surface of a fracture along which movement has occurred.Footwall The underlying side of an orebody or stope.
Gangue Non-valuable components of the ore.
Grade The measure of concentration of gold within mineralized rock.
Hangingwall The overlying side of an orebody or slope.
Haulage A horizontal underground excavation which is used to transport mined ore.
Hydrocyclone A process whereby material is graded according to size by exploiting centrifugalforces of particulate materials.
Igneous Primary crystalline rock formed by the solidification of magma.
Kriging An interpolation method of assigning values from samples to blocks that minimizesthe estimation error.
Level Horizontal tunnel the primary purpose is the transportation of personnel and
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 48/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 33
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Term Definitionmaterials.
Lithological Geological description pertaining to different rock types.LoM Plans Life-of-Mine plans.LRP Long Range Plan.Material Properties Mine properties.
Milling A general term used to describe the process in which the ore is crushed and groundand subjected to physical or chemical treatment to extract the valuable metals to aconcentrate or finished product.
Mineral/Mining Lease A lease area for which mineral rights are held.Mining Assets The Material Properties and Significant Exploration Properties.Ongoing Capital Capital estimates of a routine nature, which is necessary for sustaining operations.Pillar Rock left behind to help support the excavations in an underground mine.
QualifyingTransaction
A transaction where a CPC acquires significant assets, other than cash, by way ofpurchase, amalgamation, merger or arrangement with another company or by othermeans.
RoM Run-of-Mine.
Saprolite
A chemically weathered rock, mostly soft or friable and commonly retaining thestructure of the parent rock since it is not transported. Saprolites containpredominantly quartz and a high percentage of kaolinite with other clay minerals
which are formed by chemical decomposition of primary minerals, mainly feldspars.Sedimentary Pertaining to rocks formed by the accumulation of sediments, formed by the erosionof other rocks.
Shaft An opening cut downwards from the surface for transporting personnel, equipment,supplies, ore and waste.
Sill A thin, tabular, horizontal to sub-horizontal body of igneous rock formed by theinjection of magma into planar zones of weakness.
Smelting A high temperature pyrometallurgical operation conducted in a furnace, in which thevaluable metal is collected to a molten matte or doré phase and separated from thegangue components that accumulate in a less dense molten slag phase.
Stope Underground void created by mining.Stratigraphy The study of stratified rocks in terms of time and space.Strike Direction of line formed by the intersection of strata surfaces with the horizontal
plane, always perpendicular to the dip direction.
Stripping Ratio
The ratio of tonnes of waste rock divided by the tonnes of mineralization destined for
the processing plant.Sulfide A sulfur bearing mineral.Tailings Finely ground waste rock from which valuable minerals or metals have been
extracted.Thickening The process of concentrating solid particles in suspension.Total Expenditure All expenditures including those of an operating and capital nature.Variogram A statistical representation of the characteristics (usually grade).
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 49/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 50/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 35
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Abbreviation Defini ti on
ft square foot (feet)
ft cubic foot (feet)
g gram
g Au/t grams of gold per tonne
g/L gram per liter
g/t grams per tonne
Ga billion years
gal gallon
GGMC Guyana Geology and Mines Commission.
g-mol gram-mole
GoldHeart GoldHeart Investment Holdings Ltd.
gpm gallons per minute
gpt grams per tonne
ha hectare
HDPE Height Density Polyethylene
HFO Heavy Fuel Oil
hp horsepower
HTW horizontal true width
ICP induced couple plasma
ID2 inverse-distance squared
ID3 inverse-distance cubed
IFC International Finance Corporation
ILS Intermediate Leach Solution
Inorg-CaNP Inorganic Carbon Neutralization Potential
kA kiloampere
kg kilogram
km kilometer
km square kilometer
koz thousand troy ounce
kt thousand tonnes
kt/d thousand tonnes per daykt/y thousand tonnes per year
kV kilovolt
kW kilowatt
kWh kilowatt-hour
kWh/t kilowatt-hour per metric tonne
L liter
L/sec liters per second
L/sec/m liters per second per meter
lb pound
LCO Low Copper Ore
LGO Low Grade Ore
LHD Long-Haul Dump truck
LLDDP Linear Low Density Polyethylene PlasticLOC Low Copper Ore
LOI Loss On Ignition
LoM Life-of-Mine
m meter
M million
m.y. million years
m square meter
m cubic meter
Ma million years
masl meters above sea level
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 51/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 36
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Abbreviation Defini ti on
mg/L milligrams per liter
mL meter level
mm millimeter /millimeters
mm square millimeter
mm cubic millimeter
MME Mine & Mill Engineering
Moz million troy ounces
MPs Mining Permits
Mt million tonnes
MTW measured true width
MW million watts
N north
NAG Net Acid Generation
NE northeast
NGO non-governmental organization
NI National Instrument
NI 43-101 Canadian National Instrument 43-101
NP Neutralization Potential
N-PAG Not Potentially Acid Generating
NPR Net Potential Radio
NSR net smelter return
NTS National Topographic System
NW northwest
OSC Ontario Securities Commission
oz troy ounce
oz/t ounces per short tonne
P&E P&E Mining Consultants Inc.
PAG Potentially Acid Generating
PEA Preliminary Economic Assessment
PFS Prefeasibility Study
PL Prospecting LicensePLC Programmable Logic Controller
PLS Pregnant Leach Solution
PLs Prospecting Licences
PMF probable maximum flood
ppb parts per billion
ppm parts per million
PPMSs Medium Scale Prospecting Permits
QA/QC Quality Assurance/Quality Control
RC rotary circulation drilling
RoM Run-of-Mine
RQD Rock Quality Description
S south
Sandspring Sandspring Resources Ltd.SE southeast
sec second
SEC U.S. Securities & Exchange Commission
SEDAR System for Electronic Document Analysis and Retrieval
SG specific gravity
SPT standard penetration testing
st short ton (2,000 pounds)
SW southwest
t metric tonne (2,204.6 pounds)
t/d tonnes per day
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 52/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 53/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 38
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
3 Reliance on Other ExpertsThe Consultant’s opinion contained herein is based on information provided to the Consultants by
Sandspring throughout the course of the investigations. SRK has relied upon the work of other
consultants in the Project areas in support of this Technical Report. The sources of informationinclude data and reports supplied by Sandspring personnel as well as documents referenced in
Section 27.
The Consultants used their experience to determine if the information from previous reports was
suitable for inclusion in this Technical Report and adjusted information that required amending. This
report includes technical information, which required subsequent calculations to derive subtotals,
totals and weighted averages. Such calculations inherently involve a degree of rounding and
consequently introduce a margin of error. Where these occur, the Consultants do not consider them
to be material.
The authors wish to emphasize that they are Qualified Persons in respect of the areas in this report
identified in their certificates of Qualified Persons submitted with this technical report.
Although copies of the licenses, permits and work contracts were reviewed, an independent
verification of land title and tenure was not performed. The Consultants have not verified the legality
of any underlying agreement(s) that may exist concerning the licenses or other agreement(s)
between third parties. The authors have relied, and believe that they have a reasonable basis to rely,
upon Sandspring who has contributed portions of the tenure, legal, environmental, marketing and
taxation information stated in this report.
A draft copy of the report has been reviewed for factual errors by Sandspring. Any changes made as
a result of these reviews did not involve any alteration to the conclusions made. Hence, the
statements and opinions expressed in this document are given in good faith and in the belief that
such statements and opinions are not false and misleading at the date of this report.
All geological data were collected and compiled, and geological interpretations were performed by
the Sandspring exploration team under the management of L.W. Claessens, P. Geo, VP-Exploration,
and Pascal van Osta, P.Geo, Exploration Manager. In the appropriate sections covering the
geological data SRK has expressed its opinions on the methods of collection and data quality. SRK
considers the data to be adequate to support the resource estimation.
SRK is reliant upon Mr. Scott Issel, Chief Financial Officer of Sandspring as an expert in regard to
the projected gold and copper royalty rates, depreciation method and the Guyana corporate tax rate
used in the cashflow model presented in Section 22 of this Technical Report. SRK’s assessment of
the data provided for these aspects was that it is reasonable for use in the present PFS, on which
this report is based.
Mr. Greg Barnes, Executive Vice President, provided SRK and Tt with unit costs including projected
labor rates including payroll burdens by position for Guyana and expatriate personnel; travel costs,
mine camp unit operating costs, diesel fuel and heavy fuel oil costs, and domestic freight rates. SRK
utilized this unit cost information to develop the mining operating costs, Tt to develop the processing
operating costs, and Sandspring to develop the general and administration costs presented in
Section 21, and used in the cashflow model presented in Section 22 of this report. FMG provided
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 54/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 39
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
SRK with the estimated capital costs for port development, access roads upgrading, and bridge
construction referenced in Sections 21 and 22 of this report.
Mr. Barnes was also relied upon as an expert for the preliminary commercial terms, such as
estimated concentrate transport and insurance costs, and smelter payables, deductions, treatment
and refining costs. SRK has reviewed the projected commercial terms provided by Sandspring andthe gross gold revenue and copper credit estimates and have determined them to be reasonable and
acceptable for use in the present PFS, on which this report is based.
Sandspring has been present in Guyana for over 12 years and has obtained valuable knowledge of
the local and regional markets and thus has contributed to certain inputs.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 55/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 40
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
4 Property Description and Location
4.1 Property Descript ion and Tenure
The Property descriptions of land held by ETK have been updated based on information provided byMr. Rich A. Munson, CEO of Sandspring. The descriptions contained herein therefore supersede
those in any previous reports on the Property.
ETK, a private company in Guyana, has rights to small scale claims, Medium Scale Prospecting
Permits (PPMSs), Mining Permits (MPs), and Prospecting Licenses (PLs) within the Property. All of
ETK’s issued and outstanding stock is owned by GoldHeart. All of the issued and outstanding stock
of GoldHeart is owned by Sandspring.
Sandspring acquired its interest in GoldHeart and ETK pursuant to the terms of a share purchase
agreement dated May 11, 2009, as amended.
The Property is comprised of seven small scale claims, 167 contiguous PPMS’s and 13 MP’s that
together cover an area of 184,693.8 acres or 74,742.9 hectares, and five contiguous PL’s that cover
an area of 57,997 acres or 23,471 hectares. A list of the land tenure is given in Tables 4.1.1 through
4.1.3.
ETK has four positions of claim ownership in the Upper Puruni Area. The PL’s are wholly owned by
ETK. The seven small scale claims are located within the exterior boundaries of A-4/MP/011. Pam 1,
Pam 2, Pam 3, Joy 1, Joy 2, Joy 3 and Joy 4 located in or near the Puruni River within the exterior
boundaries of Mining Permit A-4/MP/011, described under MP’s below, and as reflected on the
records of the Guyana Geology and Mines Commission (GGMC) following verification surveys and
reviews conducted in October, November and December 2007.
The MP’s and PPMS’s identified in Table 4.1.1 and Table 4.1.2, respectively, by the prefix “A” refer
to permits which are owned by Mr. Alfro Alphonso (Alphonso), and are controlled by ETK under a
joint venture agreement (the Alphonso Joint Venture). The “Middle Ground” claims, directly north of
the Toroparu pit and south of the PL’s are held pursuant to a joint venture with Mr. Wallace Daniels
(Daniels) and are listed in Table 4.1.1 and Table 4.1.2, respectively, with the prefix “D”. The Godette
MP’s south of the PL’s and east of the Toroparu open pit are held under a joint venture agreement
with the Godette family and are listed on Table 4.1.1 and Table 4.1.2, respectively, with the prefix
“G”.
Ten parcels of land are subject to applications for the issuance of PPMS’s filed by Mr. Wallace
Daniels, a local Guyana resident. Ownership of PPMS’s covering these ten parcels of land is the
subject of a dispute between Mr. Daniels and a third party. Sandspring does not consider the
disputed parcels as having any current material value and the parcels do not form any part of the
resource estimate for the Toroparu Project and are not included in this Technical Report.
On November 9, 2011, the Company signed a mineral agreement (the Mineral Agreement) with the
Government of Guyana, which details all fiscal, property, import-export procedures, taxation
provisions and other related conditions for the continued exploration, mine development and
operation of the open pit mine at the Toroparu Project. The Mineral Agreement implements a two-
tiered gold royalty structure of 5% of gold sales at gold prices up to US$1,000/oz. and 8% of gold
sales at gold prices above US$1,000/oz., and a royalty of 1.5% on sales of copper and other
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 56/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 57/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 42
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
GS8 NumberPPMSNumber
Area(Acres)
LocationMap
NumberRenewal Date
A-184/001/0395/99 0265/2001 948 Ikuk River 44 March 11, 2014 A-184/002/0396/99 0266/2001 1137 Ikuk River 59 March 11, 2014 A-184/003/0397/99 0267/2001 987 Ikuk River 76 March 11, 2014 A-184/004/0398/99 0268/2001 1200 Ikuk River 78 March 11, 2014 A-184/005/0399/99 0269/2001 1200 Ikuk River 79 March 11, 2014
A-184/006/0400/99 0270/2001 1020 Ikuk River 98 March 11, 2014 A-184/007/0401/99 0271/2001 927 Ikuk River 97 March 11, 2014 A-184/008/0402/99 0272/2001 869 Ikuk River 77 March 12, 2014 A-184/009/99 0579/2002 804 Upper Puruni 149 August 15, 2013 A-184/010/99 0580/2002 804 Upper Puruni 148 August 15, 2013 A-184/011/99 0581/2002 780 Upper Puruni 147 August 15, 2013 A-184/012/99 0582/2002 1058 Upper Puruni 146 August 15, 2013 A-184/013/99 0583/2002 1170 Upper Puruni 150 August 15, 2013 A-185/001/99 0577/2002 795 Upper Puruni 5 August 15, 2013 A-185/002/99 0578/2002 1143 Upper Puruni 4 August 14, 2013 A-185/003/0411/99 0227/2001 795 Puruni River 3 March 07, 2014 A-185/004/0412/99 338/2001 1043 Puruni River 19 May 17, 2014 A-185/005/0413/99 0228/2001 1200 Puruni River 15 March 06, 2014 A-185/006/0414/99 0229/2001 1200 Puruni River 20 March 06, 2014 A-185/007/0415/99 0330/2001 1200 Upper Puruni 28 March 06, 2014 A-185/008/0416/99 0331/2001 1190 Upper Puruni 29 March 06, 2014 A-185/009/0417/99 0424/2001 1190 Upper Puruni 30 May 27, 2014 A-185/010/0418/99 0425/2001 1036 Upper Puruni 43 May 28, 2014 A-185/011/0419/99 0426/2001 1071 Upper Puruni 42 May 28, 2014 A-185/012/0420/99 0332/2001 1071 Upper Puruni 41 March 06, 2014 A-185/013/0421/99 0333/2001 1087 Upper Puruni 40 March 07, 2014 A-185/014/0422/99 0334/2001 1136 Upper Puruni 39 March 06, 2014 A-185/015/0423/99 0335/2001 1200 Ikuk River 38 March 06, 2014 A-185/016/0424/99 0336/2001 637 Ikuk River 58 March 06, 2014 A-185/017/0425/99 0337/2001 658 Ikuk River 57 March 06, 2014 A-185/018/0426/99 0338/2001 658 Upper Puruni 56 March 06, 2014 A-185/019/0427/99 0339/2001 607 Upper Puruni 55 March 06, 2014 A-185/020/0428/99 0340/2001 679 Upper Puruni 54 March 06, 2014 A-185/021/0429/99 0341/2001 637 Upper Puruni 53 March 06, 2014 A-185/022/0430/99 0342/2001 1125 Ikuk River 75 March 06, 2014 A-185/023/0431/99 0343/2001 1125 Ikuk River 74 March 07, 2014
A-185/024/0432/99 0344/2001 1125 Ikuk River 73 March 07, 2014 A-185/025/0433/99 0345/2001 1200 Ikuk River 72 March 08, 2014 A-185/026/0426/99 0346/2001 700 Putaring 71 March 08, 2014 A-185/027/99 0697/2002 675 Upper Puruni 70 October 16, 2013 A-185/028/0436/99 0347/2001 1150 Putaring 95 March 07, 2014 A-185/029/0437/99 0348/2001 1139 Putaring 94 March 07, 2014 A-185/030/0438/99 0349/2001 1035 Putaring 93 March 08, 2014 A-185/031/0439/99 0350/2001 1081 Putaring 92 March 08, 2014 A-185/032/0440/99 0351/2001 1200 Putaring 2 March 06, 2014 A-185/033-0441/99 0352/2001 1200 Putaring 1 March 06, 2014 A-185/034/0442/99 0353/2001 1104 Putaring 9 March 08, 2014 A-185/035/0443/99 0354/2001 1066 Puruni River 10 March 08, 2014 A-185/036/0444/99 0355/2001 1066 Puruni River 14 March 08, 2014 A-185/037/0445/99 0356/2001 1104 Tamakay 13 March 08, 2014 A-185/038/0446/99 0357/2001 1115 Puruni River 17 March 07, 2014 A-185/039/0447/99 0358/2001 1114 Tamakay 18 March 08, 2014
A-185/040/0448/99 0359/2001 1000 Tamakay 26 March 08, 2014 A-185/041/0449/99 0360/2001 1080 Tamakay 27 March 08, 2014 A-199/000/2000 620/2001 1016 Puruni River 64 September 19, 2013 A-199/001/2000 621/2001 1016 Puruni River 81 September 19, 2013 A-199/002/2000 622/2001 1200 Tamakay 82 September 19, 2013 A-199/003/2000 623/2001 1016 Puruni River 83 September 19, 2013 A-199/004/2000 624/2001 1016 Puruni River 85 September 19, 2013 A-199/005/2000 625/2001 1016 Puruni River 87 September 19, 2013 A-199/006/2000 626/2001 1016 Puruni River 115 September 19, 2013 A-199/007/2000 627/2001 1014 Puruni River 117 September 19, 2013 A-199/008/2000 628/2001 1085 Puruni River 118 September 19, 2013 A-199/009/2000 629/2001 1119 Puruni River 114 September 19, 2013 A-199/010/2000 630/2001 1125 Puruni River 103 September 19, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 58/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 43
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
GS8 NumberPPMSNumber
Area(Acres)
LocationMap
NumberRenewal Date
A-199/011/2000 631/2001 1102 Puruni River 102 September 19, 2013 A-199/012/2000 632/2001 1102 Puruni River 111 September 19, 2013 A-199/013/2000 633/2001 1076 Puruni River 112 September 19, 2013 A-199/014/2000 634/2001 1102 Puruni River 113 September 20, 2013 A-199/015/2000 643/2002 1148 Tamakay 119 October 15, 2013
A-199/016/2000 635/2001 725 Puruni River 138 September 20, 2013 A-199/017/2000 636/2001 910 Puruni River 137 September 20, 2013 A-199/018/2000 637/2001 1029 Puruni River 136 September 20, 2013 A-199/021/2000 639/2001 1011 Puruni River 32 September 20, 2013 A-199/022/2000 640/2001 995 Puruni River 33 September 20, 2013 A-199/023/2000 641/2001 965 Puruni River 34 September 20, 2013 A-199/024/2000 642/2001 958 Puruni River 48 September 20, 2013 A-199/025/2000 643/2001 1024 Puruni River 60 September 20, 2013 A-199/026/2000 644/2001 940 Puruni River 37 September 20, 2013 A-199/032/2000 649/2001 1024 Puruni River 61 September 20, 2013 A-199/033/2000 0644/2002 998 Tamakay 45 October 07, 2013 A-199/034/2000 0645/2002 998 Tamakay 47 October 07, 2013 A-199/035/2000 0646/2002 998 Tamakay 46 October 07, 2013 A-199/036/2000 0647/2002 1024 Tamakay 62 October 07, 2013 A-199/037/00 0648/2002 983 Upper Puruni 63 October 07, 2013 A-199/038/00 0649/2002 1140 Upper Puruni 49 October 08, 2013 A-199/039/00 0686/2002 912 Upper Puruni 50 October 08, 2013 A-199/040/00 0687/2002 1072 Upper Puruni 67 October 08, 2013 A-199/041/00 0688/2002 1180 Upper Puruni 89 October 08, 2013 A-199/042/00 0689/2002 963 Upper Puruni 116 October 08, 2013 A-199/043/00 0690/2002 1123 Upper Puruni 88 October 08, 2013 A-199/044/00 0691/2002 1098 Upper Puruni 86 October 08, 2013 A-199/045/00 0692/2002 1098 Upper Puruni 84 October 08, 2013 A-199/046/00 0693/2002 1123 Upper Puruni 66 October 08, 2013 A-199/047/00 0694/2002 1123 Upper Puruni 65 October 08, 2013 A-218/001/2001 0678/2002 585 Tamakay 163 October 15, 2013 A-218/002/2001 0594/2002 693 Tamakay 144 August 15, 2013 A-225/000/2001 0679/2002 1147 Tamakay 151 September 20, 2013 A-225/001/2001 0680/2002 747 Tamakay 152 September 25, 2013 A-225/002/2001 0681/2002 878 Tamakay 153 September 25, 2013 A-225/003/2001 0682/2002 484 Tamakay 154 September 26, 2013
A-225/004/2001 0683/2002 1150 Tamakay 155 September 25, 2013 A-225/005/2001 0684/2002 1140 Tamakay 156 September 25, 2013 A-225/006/2001 0475/2002 1140 Tamakay 157 July 07, 2013 A-302/001 0672/2003 1120 Puruni River 69 November 05, 2013 A-302/002 0671/2003 1120 Puruni River 140 November 05, 2013D-166/000/2004 946/04 1200 Ororiparu 167 December 07, 2013D-166/001/2004 947/04 1200 Ororiparu 170 December 07, 2013D-166/002/2004 948/04 1200 Ororiparu 171 December 07, 2013D-166/003/2004 949/04 1200 Ororiparu 172 December 07, 2013D-166/004/2004 950/04 1195 Ororiparu 168 December 07, 2013D-166/005/2004 951/04 1200 Ororiparu 169 December 07, 2013D-166/006/2004 952/04 1200 Ororiparu 173 December 07, 2013D-166/007/2004 953/04 929 Ororiparu 174 December 07, 2013D-166/008/2004 954/04 1196 Ororiparu 175 December 07, 2013D-166/010/2004 950/04 1195 Ororiparu 176 January 16, 2014D-166/011/2004 021/06 1052 Ororiparu 182 January 16, 2014
D-166/013/2004 022/06 444 Ororiparu 177 January 16, 2014D-166/015/2004 023/06 430 Ororiparu 178 January 16, 2014D-166/017/2004 024/06 445 Ororiparu 179 January 16, 2014D-166/018/2004 025/06 1052 Ororiparu 180 January 16, 2014D-166/019/2004 026/06 1052 Ororiparu 181 January 16, 2014D-181/000/2005 018/06 927 Puruni Head 165 January 16, 2014D-181/001/2005 019/06 1014 Puruni Head 166 January 16, 2014D-181/002/2005 020/06 1093 Puruni Head 164 January 16, 2014D-184/000/2005 251/06 761 Toroparu 21 May 01, 2014
Source: Sandspring, 2012
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 59/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 44
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 4.1.2: Land Tenure – Mining Permits
GS8 Number MP Number Area
(Acres)Locati on Map Number Renewal Date
A-4/MP/000// A-4/MP/010// 1145 Mazuruni 16 April 28, 2014 A-4/MP/001// A-4/MP/011// 603 Mazuruni 24 April 28, 2014 A-4/MP/002// A-4/MP/012// 858 Mazuruni 25 April 28, 2014 A-4/MP/003// A-4/MP/013// 1098 Mazuruni 23 April 28, 2014 A-4/MP/004// A-4/MP/014// 992 Mazuruni 6 April 28, 2014 A-4/MP/005// A-4/MP/015// 1145 Mazuruni 12 April 28, 2014 A-4/MP/006// A-4/MP/016// 893 Mazuruni 7 April 28, 2014 A-4/MP/007// A-4/MP/007// 1123 Mazuruni 8 April 28, 2014 A-4/MP/008// A-4/MP/008// 1117 Mazuruni 11 April 28, 2014 A-4/MP/009// A-4/MP/009// 1200 Mazuruni 22 April 28, 2014G-6/MP/000 09/2003 960 Toroparu 195 April 9, 2014G-6/MP/001 08/2003 1120 Toroparu 194 April 9, 2014G-6/MP/002 07/2003 996 Toroparu 193 April 9, 2014
Source: Sandspring, 2012
Table 4.1.3: Land Tenure – Prospect ing LicensesPL Number Area (acres) Renewal DatePL 01/2002 GS 14 E-10 11,960 September 18, 2013PL 02/2002 GS 14 E-09 11,960 September 18, 2013PL 03/2002 GS 14 E-11 11,986 September 18, 2013PL 04/2002 GS 14 E-12 10,155 September 18, 2013PL 05/2002 GS 14 E-13 11,936 September 18, 2013
Source: Sandspring, 2012
Mineral claims are subject to annual rentals by the dates as indicated in Tables 4.1.1 through 4.1.3.
Sandspring acknowledges that the rentals are paid in full for all claims as of the effective date of this
report. ETK has been, and will continue to remain, responsible for the payment of rentals. Paymentson the claims are made each year prior to the renewal date of each claim. The ten units designated
as A-4/MP/007, A-4/MP/008, A-4/MP/009, A-4/MP/010, A-4/MP/011, A-4/MP/012, A-4/MP/013, A-
4/MP/014, A-4/MP/015, and A-4/MP/016, refer to MP’s that were converted from PPMS’s.
The rental rates for each of the MPs are the sum of US$1.00 per acre per annum. The rent for each
of the thirteen MP’s is fully paid.
Mineral tenures in Guyana allow for four scales of operation. These include small scale claim
licenses of 460 m x 245 m or a river claim consisting of one mile of a navigable river. PPMS’s and
MP’s cover between 150 to 1,200 acres each and are restricted to ownership by Guyanese.
However, foreigners may enter into joint venture arrangements whereby the two parties jointly
develop the property. PL’s covering between 500 and 12,800 acres are granted to foreigncompanies. Large areas for geological surveys are granted as Permission for Geological and
Geophysical Surveys with the objective of applying for PL’s over favorable ground.
Rental rates for PL’s are US$0.50 per acre for the first year; US$0.60 per acre for the second year,
and US$1.00 per acre for the third year. An application fee of US$100 and a Work Performance
Bond, equivalent to 10% of the approved budget for the respective year, is also payable. The term
for PL’s is three years with two rights of renewal for one year each. After renewing the PL’s twice,
ETK was given permission to continue renewing on an annual basis. ETK has since requested a
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 60/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 61/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 46
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
To the best of the writers’ knowledge there are no historical environmental liabilities on the Property.
4.2 Location
The Property is located in the Upper Puruni River Area of northwestern Guyana. The geographic
location of mining operations on the Property, are located at 06° 27’ North Latitude and 60° 03’ WestLongitude, corresponding to UTM co-ordinates of 714450 N and 826200 E. The Property location is
shown on Figure 1.1.1 and the claims area is shown on Figure 4.2.1.
Figure 4.2.2 shows in detail the projected deposit and saprolite Pit outline in relation to the
interpreted IP data.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 62/340
Toroparu Gold Project,
Guyana
Figure 4.2.1
Upper Puruni Property Claim MapSource: Sandspring Resources, 2012
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 63/340
Toroparu Gold Project,
Guyana
Figure 4.2.2
Detail of Toro paru DepositSource: Sandspring Resources, 2010
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 64/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 65/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 50
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
5.4 Infrastructure Availability and Sources
5.4.1 Proximity to Population Center
With the exception of some small temporary mining camps along the access road to the Project site,
the closest village is at a distance of 230 km away. Georgetown is 385 km away by road.
5.4.2 Power
There is no nearby electricity grid. Permanent power will not be available at site prior to the
completion of construction. Construction will rely wholly on power from temporary thermal power
generators. Permanent power will be generated on site by thermal power generators.
5.4.3 Water
Water for drilling is readily available throughout the year from creeks and from rainfall run-off.
5.4.4 Mining Personnel
Laborers with a variety of experience in heavy equipment operation are available in Georgetown and
from villages situated along the nearby rivers.
5.4.5 Potential Tailings Storage Areas
KCB investigated several potential tailings facility sites, one of which was chosen for the PFS. The
selected site is located approximately 8 km to the northeast of the main Project site.
5.4.6 Potential Waste Disposal Areas
The PFS design identified appropriate areas for future waste rock disposal. The waste dumps will be
located in areas that that will not be impacted by potential future mining operations. Waste rock
produced from the Toroparu mining operations (both Toroparu and South-East pits) will be placed on
existing terrain in two designated areas. The East Dump will be located between the east of the final
Toroparu Pit and north of the South-East Pit, and the North Dump is to the north of the Toroparu Pit.
The South East Backfill Dump will be within the mined out South-East Pit area.
5.4.7 Potential Processing Plant Sites
Tt investigated several potential processing plant sites, one of which was chosen for the PFS. The
selected site is located nearby to the northeast of the planned Toroparu Pit.
5.5 Physiography
The topography is flat to gently undulating to hilly with an elevation range in the Project area of
approximately 90 to 105 masl in elevation for the mine and plant areas that is occasionally
interspersed with steep hills of meta-basic rock (up to 200 masl southwest of the mine area),
whereas the metasediments represent flatter topographies. The Toroparu Project pit is adjacent to a
very gentle valley and the area surrounding the pit has had small berms constructed to contain the
tailings from past mining operations.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 66/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 51
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
6 HistoryThe following is a summary of the activities history of the Toroparu area.
Late 1880's to 1950
Historic exploitation of alluvial gold and diamonds in the Toroparu area dates back to about 1887.
Conolly (1926) described alluvial diamond operations up to about 1914, to the northwest of the
Toroparu area. Grantham (1934) described gold and diamond workings in the Majuba Hill and
Wynamu areas. The Wynamu River lies adjacent to the Toroparu pit and is labeled as “Toroparu
River” on some older maps.
Pollard and Hamilton created a geological map of the area in 1950 on which the locations of gold
and diamond workings were noted (Pollard, 1950).
6.1 Alluvial and Saproli te Exploration and Mining - 1997 to 2006
During the period of 1997 to 2006 the exploration and mining on the Toroparu property wasconducted as alluvial placer mining operations that in part mined into saprolite in the current pit area.
Exploration during this time was focused on saprolite bearing gold mineralization.
1997
Alphonso commenced alluvial mining at Toroparu in 1997; mining old placer tailings and river
alluvium by washing material into a pit with high pressure water jets and pumping the slurry up to a
sluice box. By 1999, much of the alluvial material was exhausted and work proceeded deeper into
the underlying saprolite and laterally to the west into the saprolite of the hill slope so that the surficial
alluvial area was gradually developed into a 15 to 20 m deep pit (the Toroparu open pit). The
Alphonso operations continued until 2001.
1999
ETK began auger drill sampling to the east and west of the pit area and also evaluated the possibility
of re-working the tailings. Reports by Hopkinson (1999), Uzunlar (2000) and Shaeffer (2000, 2001,
and 2003) summarize the available assay data.
2000
The Guyana Geology and Mines Commission (GGMC) carried out regional mapping and
geochemical stream sampling (Heesterman, et al., 2001) that showed an anomalous gold and
copper area in the immediate Toroparu area.
ETK entered into an exploration joint venture with Alphonso and commenced rehabilitation and
upgrading a 240 km access road into the Property to facilitate the transport of mining equipment and
supplies to the mine site.
2001
Alphonso ceased mining operations in 2001 in the Toroparu open pit. A total of 15 “land dredges”
were employed at the peak of the Alphonso mining activity in the Toroparu open pit area. It has been
estimated that 60,000 oz of gold may have been produced historically over a 70-year period from the
Toroparu area by these alluvial washing methods.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 67/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 52
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
2001-2003
ETK carried out further auger drill sampling in 2001 and 2003 to the east and west of the open pit
area. This work reportedly identified an estimated 1.4 Mt of historic auriferous tailings located
southeast of the main pit area.
2003-2004
Heesterman carried out drainage geochemical sampling for ETK in the PL blocks, located north of
the Toroparu pit area and on lands granted to ETK in 2002. Further geochemical sampling was
performed around the pit area and results indicated that gold mineralization could extend at least
6 km to the northwest and 1 km to the southeast of the Toroparu open pit
2004
ETK commissioned a gravity circuit to test-mine the gold-bearing placer tailings and saprolite, and
also conducted exploration for additional gold sources defined in the GGMC regional geochemical
and prospecting survey of the Upper Puruni area.
From December 2004 to April 2007 ETK conducted intermittent, seasonal test-mining from saprolite,
in the Toroparu pit using a combination of hydraulic sluicing and a gravity circuit with screens, ball
mill, Falcon centrifugal concentrators and shaker tables.
2005
In 2005 and 2006, two phases of trench-channel sampling were completed by Meixner and Wesa to
investigate the gold mineralization in the saprolites of the pit area and to determine the suitability for
conducting further exploration. A zone of gold mineralization, over an area of about 180 m x 100 m,
was identified in the saprolitic rock of the pit area with average grades in the general range of 0.5 to
1.5 g Au/t. This zone was open in all directions.
6.2 Bedrock Exploration - 2006 to 2009
ETK initiated a bedrock exploration and drilling program in 2006 which has culminated in the initial
knowledge of the saprolite and bedrock mineralization at Toroparu. During this time, local alluvial
placer mining continued.
2006-2007
TerraQuest conducted a 5 km x 4.5 km high resolution Tri-sensor Magnetic and Radiometric
Airborne Survey around the Toroparu Pit area in October 2006 on behalf of ETK. The pit area was
found to lie within a magnetically low area just to the south of a large magnetic high area of unknown
provenance. The survey outlined a number of magnetic and radiometric anomalies in the areas
adjacent to the current Toroparu deposit
ETK initiated the Phase 1 drill program in December 2006 as recommended by Meixner and Wesa
(Meixner and Wesa, 2006). Phase 1 included the drilling of 13 NQ core drillholes (3,480 m) under
and around the Toroparu open pit; the program was completed by March 2007. Phase II drilling of an
additional 10 NQ core drillholes (3,748 m) was completed in August 2007. Phase I and II drilling
defined a mineralized block of 600 m x 300 m x 300 m around the Toroparu Pit area (Meixner, 2008).
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 68/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 53
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
2008
The ETK Phase III drill program, consisting of 6 NQ cored drillholes (2,590 m), was undertaken from
April to May of 2008. A total of 30 drillholes (TPD 001-030) comprising 10,218 m defined a zone of
mineralization of 650 m x 350 m x 425 m; that was open in all directions. Twenty seven holes totaling
9,492 m formed the basis for the initial mineral resource estimate published in P&E’s TechnicalReport No. 153, effective October 26, 2008, titled “Technical Report and Resource Estimate on the
Toroparu Gold-Copper Prospect, Upper Puruni River, Guyana” (P&E, 2009), as stated in Table
6.2.1.
Table 6.2.1: Toroparu 2008 Mineral Resources
Source: P&E, 2009
ETK carried out additional auger drill sampling to the northwest of the pit area over a 2 km x 3 km
area, using a mechanized auger. Nine north-easterly lines of auger samples, spaced 500 m apart,
were sampled to 5 m depths at approximately 50 m sample intervals. This survey tested the
saprolitic rocks beneath the alluvial cover for gold and copper in an area of historic placer gold
workings that lies to the northwest of the Toroparu open pit area.
An Airborne Geophysical Project was completed in the fourth quarter of 2008 by Allan Spector and
Associates Ltd., consisting of a fixed wing magnetometer and spectrometer survey, totaling
12,400 km of data along 100 m and 200 m spaced north-south oriented flight lines, and covering the
entire ETK Upper Puruni concession surface (+/- 1000 km²).
2009
The ETK Phase IV drilling program conducted between August and December 2009 comprised 21
core drillholes (10,102 m). Thirteen holes were drilled over the Toroparu open pit area with depthsupwards of 500 m and others were drilled as off-trend exploratory holes, as recommended by P&E
(P&E, 2009).
Approximately 2,500 geochemistry saprolite samples were collected using hand and power augers
during 2009, to depths from 1 to 15 m. The soil grids were oriented perpendicular to regional
structures, extending approximately 4.5 km to the WNW from the Toroparu resource area. Assay
results show several areas of gold enrichment along trend to the NW with the highest assay value
equal to 9.94 g Au/t.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 69/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 70/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 71/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 56
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
SRK has not reviewed the 2008 or 2010 resource estimates, as they are not current and should not
be relied upon. The historical resource estimates are provided here for an understanding of the
progression of resource estimation at the Toroparu Project. Current Mineral Resources are stated in
Section 14 of this report.
6.3.2 2011 Programs
Resource definition core drilling
This drill program was the main activity during 2011, particularly focused on the eastern main
mineralized zone of the Toroparu deposit. A total of 120 holes were drilled totaling 42,320 m. The
objective of this drill program was to increase the overall resources and the average grades of gold
and copper, as well as the conversion of resources from the Inferred to Measured and/or Indicated
categories. Priority was given to the eastern mineralized zone of the deposit (Main Zone), which has
a higher average gold/copper grade and contains around 65% to 70% of the known global
resources.
At the end of 2011, and over a period of six years (December 2006 to December 2011), a Projecttotal of 111,668 m of resource definition drilling was realized in 225 core holes.
Metallurgy – Gold Deportment Study
This study was carried out by SGS on a 400 kg composite sample of the Toroparu mineralization
and collected in 23 different core holes. Results were received in May 2011. The objective of this
investigation was to determine the occurrence of gold, including microscopic and submicroscopic
gold in the sample, and identify and evaluate any mineralogical factors that might affect potential
gold recoveries.
Step-out Exploration Core Drilling
A total of 78 core holes, totaling 24,834 m were drilled in adjacent zones north-west and south-eastof the Main Zone deposit area in order to explore for significant and economic extensions of the
resource or nearby satellite deposits.
Exploration Core Drilling
Small recon core drilling campaigns were carried out over areas with promising surface exploration
results; including the Ameeba and Manx areas, located respectively at several kilometers north-west
and north-east of the Toroparu deposit. A total of 28 holes for 8,405 m were completed.
Geochemical Exploration
A regional saprolite geochemistry sampling campaign was started in March 2011. The survey was
focused on areas with presumed geological potential for gold. Semi-regional and detailedgeochemical sampling was performed on areas where alluvial mining activities showed gold
potential. At the end of the year a total of 4,390 samples were collected.
Ground Geophysics
Combined Gradient Array IP and Magnetometer surveys were carried out over several gold
prospects, including Ameeba, Timmermans, Manx and NW of the Toroparu deposit, completing the
grids of the 2010 surveys. An additional 17 line-km of survey were completed.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 72/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 57
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
LIDAR Survey
During the course of the second quarter of 2011, a LIDAR survey was flown over an area of 250 km²
around the Toroparu deposit zone. This technology (Light Detection and Ranging) is an airborne
laser swath topographic mapping (ALSM) system. It is amongst the only methodologies which
provides accurate and high precision topography contour maps in tropical forest covered zones. Adetailed topographic contour map was produced from this data.
Road Project
After the acquisition of additional road construction equipment, Sandspring commenced, in June
2011, an improvement and rehabilitation project of the access road to the Toroparu site (total
distance 240 km).
Mineral Agreement
A Mineral Agreement was signed in November 2011 between the Government of the Republic of
Guyana and Sandspring. The Mineral Agreement defines s all fiscal, property, import-export
procedures, taxation provision and other related conditions for the continued exploration, minedevelopment and mining/processing operations at Toroparu. Furthermore, the Government of
Guyana has agreed to grant a large-scale mining license, which will allow the start of commercial
production, once economic feasibility is demonstrated.
Resource Update and NI 43-101 Technical Report No. 208
Drilling through an effective date of December 31, 2010 was incorporated by P&E Engineering into
an updated mineral resource estimate and an initial PEA NI 43-101 Technical report No. 208 dated
May 5, 2011 (P&E, 2011) (Table 6.3.2.1).
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 73/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 74/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 59
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
During the course of 2012 a total of 34,055 m, in 142 holes were completed for the Toroparu deposit
area. At the end of 2012, and over a period of six years (December 2006 through December 2012), a
Project total of 145,723 m of resource definition drilling was completed in 367 holes.
Exploration Drilling
Exploration drilling consisted for the larger part of Reverse Circulation (RC) holes, drill testing the
main gold anomalies, which were revealed in the area around the Toroparu deposit by the saprolite
geochemical program during the course of 2011. The total RC drill meterage amounted 15,633 m in
168 holes.
Geochemical Exploration
Regional and detailed saprolite hand-auger sampling and testing concerning regional gold potential
and local gold anomalous zones was conducted. A total of 3,480 samples were collected. Over the
course of 2011 and 2012 the geochemical surveys covered around 450 km² and a total of 7,850
geochemical samples were collected.
Airborne Geophysics Reprocessing
Re-analyses of the 2008 airborne geophysical survey data was carried out by a geophysical
consultant. The work consisted in a basic structural interpretation of the aeromagnetic and
radiometric data, and an attempt to characterize the geophysical signature of the Toroparu deposit.
This study contributed significantly to the development of a regional exploration model.
Road Rehabilitation Project
The road repair and maintenance work continued for the whole year. In 2012 a road work contract
was signed with the GGMC (Guyana Geology and Mining Commission), financing part of the total
road rehabilitation costs. Part of the work (+/-100 km) was subcontracted to MMC (Mekdeci
Machinery and Construction), a local construction company.
Preliminary Road Construction Study
After several field visits, FMG Engineering completed a Preliminary Design Study in March of 2012
on the access road reconstruction, from the Itabali port facility to the Toroparu site (230 km);
including a conceptual roadway reconstruction design plan, cost estimates and preliminary
solicitation of qualified contractors.
Environmental Permit
This permit was signed and granted to Sandspring Resources by the Environmental Protection
Agency in June 2012.
Hydro-electrical Project
A monitoring program to assess Kumurung river flow characteristics upstream and downstream and
rain fall measurements in the Project watershed started in September 2012 and is ongoing.
Updated Preliminary Economic Assessment
The culmination of all Sandspring work programs from inception of the land agreement in 2009
through October 2011 was the completion by P&E and Sandspring of an updated PEA (Scoping
Study) and a NI 43-101 Technical report No. 234 titled “Updated Resource Estimate and Preliminary
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 75/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 76/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 61
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
In 2003 ETK submitted a composite sample of saprolite, weighing 150 kg and with a calculated
grade of 2.80 g Au/t, to Hazen for testing (Hazen, 2003). Test work showed that with
minus 100 mesh grinding and gravity concentration, up to 80.1% of the gold could be recovered.
Recovery increased to 93.9% with froth flotation of the gravity tailings.
Beginning in 2004, ETK intermittently carried out test-mining of the saprolite from the pit, neverachieving recoveries of more than about 18%. Low recoveries were attributed to the predominance
of fine, micron-sized gold flakes in combination with high viscosity saprolite ore slurries, making
gravity capture of the gold very inefficient.
In October 2005, Meixner and Wesa (Meixner, 2006) sampled ore slurries (with average grades of
2.58 g Au/t) that were being mined by ETK. Tailings samples, taken during the same time interval as
the ore slurries were being processed returned 2.13 g Au/t, indicating significant gold loss in the
concentrator plant and gold accumulation in the tailings pond.
During the period from November 19, 2005 to February 28, 2006, accurate production records were
kept by ETK of saprolite ore processing through the pilot gravity separation plant (Shaffer, 2006). A
total of 59.625 kg (1,917 oz) of gold were recovered from 199,297 t of saprolite ore for a calculatedrecovered grade of 0.30 g Au/t. An average grade of 2.64 g Au/t was determined and analyzed at
Loring Laboratories in Georgetown. The recovery rate of the gravity circuit was calculated to be 11%.
In February 2006, R. Hyyppa, P.E., consulting mining engineer to ETK, conducted an analysis of the
gravity separation procedure (Hyyppa, 2006b) at Toroparu by testing the addition of a flotation circuit
to improve gold recoveries (Hyyppa, 2006a). Results showed that 99.5% of the gold in the
concentrate occurred in the -150 mesh fraction and that between 49% and 95% of the gold was
theoretically recoverable by flotation.
In 2009, Sandspring contracted SGS Lakefield Research Limited Metallurgical Testing, to carry out
initial metallurgical testwork on samples of saprolite ore, saprolite tailing mixture and hard rock from
the Toroparu deposit. Testing has indicated positive results for copper and gold in both the hard rock
and saprolite samples.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 77/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 62
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
7 Geological Setting and Mineralization All geological data were collected and compiled and geological interpretations were performed by the
Sandspring exploration team under the management of L.W. Claessens, P. Geo and VP-Exploration
and Pascal van Osta, P.Geo and Exploration Manager. This section of the report is the result ofthese efforts and is written by the exploration managers.
7.1 Regional Geology – Guiana Shield
The Guiana Shield underlies the eastern part of Venezuela, Guyana, Surinam, French Guyana and
parts of northern Brazil. It consists of three major geological subdivisions (see Figure 7.1.1). In
Venezuela the Imataca Complex basement rocks are composed of Archean age formations of high-
grade metamorphic rocks and dispersed granitoid plutons, all older than 3.0 Ga. The younger
granitic and volcano-sedimentary terrains are of Paleo-Proterozoic age, ranging from 2.2 to 2.0 Ga,
and are unconformably overlain (covered) in the western part of the shield by the anorogenic clastic
sedimentary sequences of the early Mid-Proterozoic Roraima Formation.
The Toroparu property is located in northwestern Guyana, which is mainly underlain by alternating
volcano-sedimentary belts and large granitoid batholiths of Paleo-Proterozoic age. These
supracrustal rocks form the northern part of the Guiana Shield, which represents the northern
segment of the Amazonian Craton in South America, and is a dismembered portion of the West
African Craton. The West African Craton is well known for its gold potential and numerous tentative
correlations have been made to compare these lower Proterozoic terrains.
Over the last several decades numerous economic gold deposits were discovered in the West
African Craton, in particular in the lower Proterozoic volcano-sedimentary sequences. Most of these
deposits are in production, examples are Obuassi, Ayanfuri, Ahafo, Tarkwa, Chirano and Boguso
gold deposits in Ghana; the Sadiola, Yatela, Tabakoto, Morila and Syama deposits in Mali; theSabodala deposit in Senegal; the Essakane, Taparko, Mana and Youga deposits in Burkina Faso
and the Tongon, Ity and Bonikro gold deposits in Côte d’Ivoire.
The larger part of the Guiana Shield is geologically underexplored. Geological mapping and regional
exploration is hampered by dense tropical vegetation and thick lateritic/saprolitic weathering profiles.
Nevertheless, apart from the significant gold discoveries at Las Christinas, El Callao and others in
the Kilometre 88 district of Venezuela, Omai in Guyana, and Gros Rosebel in Suriname, increasing
alluvial mining and exploration activities since the 1990’s has demonstrated the excellent gold
potential of the Guiana Craton portion of the Amazonian Craton. Sizeable gold deposits have been
defined in metamorphosed volcano-sedimentary sequences in the Guiana sub-region. In Guyana for
example, multi-million ounce gold deposits occur at Aurora, Toroparu, and Hicks/Smart, and less
than 1 Moz gold deposits are present at Tassawini, Eagle Mountain and Million Mountain.
In the northern and northwestern parts of Guyana, the supracrustal sequences constitute the
Barama-Mazaruni Supergroup and form three curved, northwest-southeast oriented sub-parallel
belts, which show a similar regional lithostratigraphy. Limited field information seems to indicate that
each of the belts is comprised at the base of mafic tholeiitic basalts and minor ultramafic rocks,
overlain by volcanic rocks of intermediate composition alternating with terrigeneous sediments.
These sequences are interpreted to have formed as successive back-arc closure and extensional
oceanic-arc systems between 2200 and 2100 Ma (G.Voicu et al., 2001). In Suriname and French
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 78/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 63
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Guyana, molasse type sediments form sequences of siltstones, greywackes and conglomerate,
unconformably overlying the volcano-sedimentary sequences. Geochronological data suggest ages
around 2125 Ma, which correlates well with the Tarkwanian, gold bearing, clastic sediments of West
Africa (Milesi, 1995). The extension of these terrigenuous facies to the west into Guyana has not
been mapped, but there are indications they exist.
Crustal shortening is reflected by polyphased deformation, which resulted in shearzone dominated
strain and tight folding, arranging the volcano-sedimentary sequences in more or less elongated
belts.
The above described supracrustal sequences are intruded by numerous, large and small calc-
alkaline felsic to intermediate granitoid intrusions, called the “granitoid complex”, with ages ranging
from 2140 to 2080 Ma (G.Voicu, et al., 2001). These plutons form large batholithic zones in between
the volcano-sedimentary belts, and as small plutons within the belts.
The lack of systematic geological mapping data and large scale remote sensing studies results in the
regional framework of the Paleo-Proterozoic terranes of the Guyana shield being poorly
documented. The region is marked by several large scale shear zones. The most prominent of thesestructural corridors stretches over several hundreds of kilometers in a west-northwesterly direction
across most of the Guyana Shield. In Guyana this feature is known as the Makapa-Kuribrong Shear
Zone (MKSZ; G.Voicu, et al., 2001). An interesting observation is that a majority of the known gold
mineralization systems are located in the vicinity of these regional tectonic features.
7.2 Regional Geology – Western Guyana
The concession package of Sandspring (1000 km²) is located in the Upper Puruni area, in between
the Cuyuni and Mazaruni rivers, in the north-west part of Guyana. The regional geology of this area
is described by Heesterman, et al., in a 2001 Guyana Geology and Mining Commission (GGMC)
report, as well as in several of Heesterman’s internal ETK reports dated 2003 and 2004, andupdated in 2005 (see references section). Voicu, et al. (1999), gives a concise description of the
regional geology of the Omai mine area, which reflects a broadly similar geology to that at Toroparu.
Figure 7.2.1 shows the most current geology sketch map of the Upper Puruni region.
Geological mapping is hampered by dense tropical vegetation and thick lateritic/saprolitic weathering
profiles, causing a general lack of bedrock exposure. As a consequence regional geology knowledge
is quite limited. In the context of these limitations Sandspring’s geology team made an attempt to
draw a comprehensive litho-structural sketch of the Upper Puruni area, using all available regional
data (Project and public data): airborne magnetics and radiometrics, topographic documents (DTM,
SRTM maps, JERS sat images), existing geological maps, and regional geochemical data. This work
tries to provide a contribution to the overall understanding of the regional litho-structural patterns.
Combining geophysical and geochemical features with topographic landscape textures along with
basic information from the official geological map, it was possible to distinguish several probable
volcano-sedimentary sequences and intrusive structures within a regional tectonic framework (Figure
7.2.1).
The northeastern half of the Upper Puruni concession is underlain by thick volcano-sedimentary
sequences consisting of alternating mafic, intermediate and to a lesser extent, felsic volcanic flows
and pyroclastics, with intercalated sedimentary successions, generally metapelites and greywackes.
These formations form the Puruni volcano-sedimentary (VS) belt which extends in a northwesterly
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 79/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 64
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
direction in between two large plutonic areas, the Aurora batholith located to the northeast of the
concession, and the Putareng batholith underlying most of the southwestern part of the property
(Figure 7.2.1). Regional metamorphic grade is greenschist facies and can reach the amphibolite
facies in the vicinity of the granitoid intrusions. Limited lithological information provided by scarce
outcrops and exploration drill logs suggest that the central part of the belt is predominantly occupied
by thick sequences of pyroclastics and sediments; whereas, the border zones are dominated by
mafic volcanics. Some strongly weathered rock in road cuts, and associated multi-element
geochemistry, suggest the presence of ultramafic facies, which seem to be related to the mafic
volcanic sequences.
The Putareng batholith corresponds to a calc-alkaline composite intrusive complex, ranging in
composition from granite and tonalite to diorite. In the literature it is suggested that these intrusives
developed synchronous to late in the orogenic cycle. Exploration revealed the existence of small,
more or less elongated, intra-belt plutons, generally of tonalitic to quartz-dioritic composition. The
Toroparu gold-copper deposit developed along the contact zone of one of these small intrusive
bodies (Figure 7.2.1). Reprocessed airborne magnetics data and satellite imagery interpretations
provide indications that these small plutons seem occur preferentially at “Mag low” structures along
the southern limb of the Puruni VS belt (Figure 7.2.1). Several significant gold deposits in Guyana
are related to such small intrusive bodies: Aurora, Omai and Toroparu. Petrographic,
geochronological and litho-geochemical studies are required to investigate in detail the age of the
different intrusive phases and their eventual l ink with gold (copper) mineralization.
Younger, mafic intrusions are widespread over the area and form generally irregular shaped bodies,
probably remainders of large sills and dikes, respectively. unconformably overlying or discordantly
cutting through the Paleo-Proterozoic formations. These mafic intrusives consist mainly of dolerites
or diabase and are related to the early Meso-Proterozoic Roraima basin formation.
Remote sensing imagery (SRTM and JERS) and airborne geophysical maps provide useful
information and allow preliminary interpretations of the regional tectonic framework of the Upper
Puruni area. However the general lack of bedrock outcrops and hence geological field observations
hinder further study of these structural interpretations.
The Upper Puruni area is marked by sets of NW to WNW and NNW to N-S lineaments (Figure
7.2.1). The NW oriented features seem to constitute typical belt parallel shearing structures,
following lithological contact zones and dominating the regional trend of the belt. The regional
structural pattern shows a sigmoidal flexure zone in the northwestern part of the concession, which
seem to be controlled by the set of NNW to NS lineaments. The flexure zone, if the fractures are
strike-slip shear zones, can be an area of right-hand rotational deformation. Unfortunately, there is
very little structural information available, which makes basic and reliable structural analyses difficult.
The Toroparu deposit occurs close to the crossing of the WNW trending Puruni lineament and the
NNW oriented Wynamu lineament.
7.3 Property Geology
A significant resource definition drilling program was completed from the end of 2006 to the end of
2012 on the Toroparu deposit, which provides the basis for understanding the Project geology. Drill
core logging allowed for detail understanding of the lithology, structure, and the gold–copper
mineralization in bedrock.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 80/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 65
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
7.3.1 Weathering
Toroparu is located in the immediate vicinity of the confluence of the Puruni and Wynamu rivers, is in
a topographically low area, and the upper part of the lateritic profile has been eroded. The bedrock
substratum is overlain by a thin, on average 1 to 2 m residual soil layer, followed by a 25 to 35 m
thick layer of saprolite. Sap-rock is the transitional zone between saprolite and fresh rock, and formsas a gradational contact a few meters thick.
Saprolite is the result of deep tropical weathering, resulting in the larger part of the original rock
mineralogy being replaced by clays. However, part of the original rock textures can be preserved
with clay pseudomorphs. Quartz veins and veinlet networks survive quite well in saprolite, and
contain occasional free gold grains. In general, sulfides are completed leached and removed in the
saprolitic weathering layer, leaving relict voids or oxidized spots. Sulfides can be partly preserved in
the sap-rock horizon.
7.3.2 Lithology
The Toroparu gold-copper deposit occurs along the northwestern boundary of a tonalitic to quartzdioritic intrusion, close to the south-eastern edge of the pluton (Figures 7.3.2.1 and 7.3.2.2).
Throughout most of the deposit zone, hydrothermal alteration is quite intense and hampers
macroscopic as well as microscopic descriptions in order to identify and distinguish the volcanic and
intrusive rock types. Moreover most of these magmatic lithologies display comparable intermediate
mineralogical compositions.
On a deposit scale, the western part of the Toroparu mineralization system and the SE satellite
deposit are predominantly hosted by intrusive rocks (Figure 7.3.2.1: West Zone, Main West Zone
and SE Zone). The abundant presence of xenoliths of volcanic rocks indicates that the zones
correspond to the roof of the intrusive. In the eastern part of the deposit area (Main East Zone), the
mineralization forms an elongated cloud along a contact zone of a greenschist metamorphic volcanicsequence, draped over a deeper seated tonalitic intrusive (Figures 7.3.2.1 and 7.3.2.2).
The different zones of mineralization are interpreted to be separated by WNW and NNW oriented
fault sets.
The intrusive lithologies are tonalite to quartz diorite in composition and display a medium grained
granular (hypidiomorphic), massive, but often porphyritic texture.
The tonalites intrude a sequence of greenschist metamorphic volcanics of intermediate to mafic
composition, consisting of fragmental pyroclastics (possibly volcanic breccia or debris flows with
predominantly felsic clasts) alternating with fine grained tuffaceous layers, grading locally into
coarser lapilli and local intermediate to mafic lava flows, often porphyritic. North of the deposit areathe pyroclastics grade into fine grained and laminated arenaceous and pelitic sediments.
At depth, in the vicinity of the above described intrusive contact, and associated with zones of higher
grade gold, several core holes intersected dacitic to quartz-andesitic composition rocks, displaying a
fine grained, massive but often fine to micro-porphyritic texture. These rocks, described as “probably
of sub-volcanic (hypabyssal) origin” in petrographic analyses, seem to form irregular bodies in the
meta-volcanics and intrusives. The volcanic and intrusive rocks are intruded by sets of discontinuous
sub-vertical mafic dikes of variable widths, from a few tens of cm to over 10 m. The dikes show a
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 81/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 66
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
relict original mafic intrusive mineralogy and texture overprinted by a greenschist metamorphism
mineral assemblage.
7.3.3 Structure
Detailed core logging shows that the volcano-sedimentary sequence and the intrusive rocks did notundergo a strong overall deformation.
The volcano-sedimentary sequence of alternating coarse and fine volcanoclastics, and lava flows
appear as massive non-foliated layers. Unit boundaries are generally not well expressed, which is
probably due to strong alteration, and that makes the observations and/or interpretations of eventual
fold systems difficult. The tonalites show an overall massive texture and appear as an undeformed
intrusive rock.
Foliation occurs locally and is probably associated to small local shear fractures. Foliation is
relatively frequent in the transition zone between the Main Eastern and Western zones and is related
to the NW-SE fault system separating the two main mineralized bodies.
On a deposit scale relatively dense fracture networks seem to occur by preference in elongated E-W
oriented and west plunging lenticular bodies, which, in particular in the Main Eastern and the SE
zones appear as higher grade mineralization features. Dense fracturing associated to higher grade
gold and copper mineralization seems to develop more or less along the intrusive contact and cross-
cuts as well the meta-pyroclastic sequences, the hypabbysal intrusives or subvolcanic facies, and
the tonalities/quartz diorites. Around these higher grade core features and towards the borders of the
deposit, fracturing intensity gradually decreases and gold and copper grades drop. A similar
structure, but less well expressed because of lower grades, has been detected in the Main West part
of the deposit.
Most of the Upper Puruni region is characterized by a pattern of conjugated sets of WNW to NW and
NNW to NS lineaments, which are probably shear fractures. The Toroparu deposit is located close toand between two major lineaments: the WNW-oriented Puruni lineament, to the south-west and the
NNW striking Wynamu linear structure. The Wynamu affects and off-sets the south-east part of the
deposit and is post-mineralization. Within such a regional structural pattern, the mineralized zones of
the Toroparu deposit can be interpreted as east-west oriented, west plunging, dilational zones within
a NW to WNW oriented, oblique sinistral strike-slip fault zone. It is clear that more structural
evidence is needed to fully support this interpretation of higher grade E-W lenses within the overall
WNW oriented deposit geometries.
7.3.4 Alteration
Over most of the deposit area the volcanic and intrusive facies are affected by a quite stronghydrothermal alteration. Core logging defines irregular zones of silicification and
sericitization/chloritization, with associated epidote. Carbonate is ubiquitous in most lithologies as
small disseminated grains in the groundmass, sometimes giving the finer grained facies a micro-
porphyritic aspect, and is abundant and associated to quartz in veinlets.
Microscopically the most common alteration assemblage, overprinting the original rock mineralogy, is
propylitic/phyllic in nature: albite – actinolite - (tremolite) – chlorite – sericite – carbonate – epidote –
± local quartz. Petrographic analyses describe a hydrothermal assemblage containing secondary
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 82/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 83/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 84/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 85/340
Toroparu Gold Project,
Guyana
Figure 7.2.1
Upper Puruni DistrictRegional Geological Sketch
Source: Sandspring Resources, 2013
(L.W. Claessens, 2012)
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 86/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 87/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 88/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 89/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 74
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
8 Deposit TypeThe existing exploration results suggest that the Toroparu deposit is a gold-copper-bearing
mineralized system hosted by a sequence of metamorphosed pyroclastics and minor volcanic flows
and sediments adjacent to an altered granodiorite pluton. The mineralization consists ofdisseminated sulfides in a veinlet and fine fracture/stockwork, which could be shear-zone related.
The genesis of the mineralized system and related alteration is not well understood and still based
mainly on macroscopic observations (core logging). Additional geological, petrographical,
mineralogical and chemical work is required to help define the deposit model and its geological
context.
The Las Cristinas and Las Brisas deposits, forming a large gold-copper mineralization system, are
located in the southeastern part of Venezuela (Channer, et al., 2005; Cristinas and Brisas Tech. Rep.
resp. 2007-2008; total reserves 27 Moz) and 150 km west of the Toroparu deposit in a similar volcano-
sedimentary belt. These deposits share the same economic constituents (gold, copper and silver) and
similar volcanoclastic host rocks. However, there are substantial differences with respect to thegeological context and the mineralization style. The Venezuelan deposits form stratiform and foliation
parallel to elongated mineralized lenses within sheared mafic pyroclastics and volcanics, and are
marked by the absence of intrusive stocks and quartz-(carbonate) vein stockwork. (Channer, et al.,
2005; Addison, et al., 2006, for Gold Reserve Inc.)
The Toroparu deposit shows a better resemblance to the Archean-aged Boddington deposit. Both
deposits are hosted by greenschist metamorphosed volcanics, sub-volcanics, and intrusives, and
show a similar mineralization style. The Boddington deposit in Australia is interpreted as a
structurally controlled, low-sulfidation, intrusion-related Au-Cu deposit formed by two overprinting
magmatic-hydrothermal events. The bulk of the mineralization and associated alteration are
genetically related to a K-rich post tectonic magmatic suite of intrusions (McCuaig, et. al., 2001).Table 8.1 shows the primary geological and mineralogical features of the Toroparu Au-Cu deposit in
relation to other similar deposit of the Guiana Craton.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 90/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx
Table 8.1: Primary Geological and Mineralization Features of Several Gold and Gold –Copper Deposits
Toroparu Aurora Omai Eagle Mt Gros R
Company Sandspring Res. Guyana Gold Fields IamGold Eagle Mt. Corp. IamGo
Country Guyana Guyana Guyana Guyana Surina
Commidit y gold-copper-(silver) gold gold gold gold
Host lithologies pyroclastics; lava flows tonalite-diorite Q-diorite ; granodiorite porphyry clastic Ass oci ated rocks intermed. -mafic sediments, mafic volc. andesite-basalt andesite : sediments felsic v
tonalite; Q-diorites felsic volc.; sediments volc.
Metamorphic grade lower greenschist lower greenschist lower greenschist lower greenschist middle
(of host rocks)
Structural setting oriented brittle fracture vein stockwork (intr) stockwork vein stockwork (intr) brittle-d
network in volc./intr. brittle-ductile brittle shearing shearing( volc-sed)
shearing (volc-sed)
Ore/gangue mi nerals chalcopyrite-bornite- pyrite pyrite, galena, chalco- pyrite, magnetite, pyrite,
pyrite-molybd.-chal- quartz-ankerite pyrite, pyrrhotite, molybdenite, chalco- pyrite-q
cite, quartz, carbonate sphalerite, molybd. pyrite, scheelite feldspa
quartz, biotite
Hydrothermal alter. sulfidation; carbonatiz.; silicification; sericitiz.; sulfidation; carbonatiz.; silicific.; sulfidation; potassi
silicific.; sericitiz.; albitisation; carbonatiz. silicific.; sericitiz.; sericitiz.; chloritiz;. carbon
chloritiz.; albitization sulfidation chloritiz.; albitization argillic Structural ti mingof mineralization
Late to post- tectonic syn- to late tectonic late to post tectonic late to post tectonic syn- to
Age o f m ineral izat ion unknown unknown 2002 Ma unknown unknow
Source: Voicu et al., 2001; modified by Sandspring Resources, 2013)
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 91/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 76
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
8.1 Geological Model
The existing exploration results suggest that the Toroparu Deposit is a gold-copper-bearing
mineralizing system hosted by a sequence of metamorphosed pyroclastics and minor volcanic flows
and sediments adjacent to an altered granodiorite pluton. The mineralization consists of
disseminated sulfides in a veinlet – fine fracture stock work, which could be shear-zone related.
During 2012, a re-logging exercise was performed of most of the existing holes within the resource
zones with the objective to standardize geological descriptions and develop a reliable geological
model of the Toroparu gold-copper deposit, including the definition of geological limits for the
resource modeling.
Geological cross-sections (Figure 7.3.2.2) were generated by Sandspring geologists and examined
with the drillhole database. It is difficult to identify clear litho-structural boundaries for the
mineralization system. The drilling delineates zones of Au-Cu veinlets and mineralized fractures
containing minor sulfides (pyrite and chalcopyrite primarily), defined as stockworks or possibly shear-
related WNW to West trending and near vertical structural zones, and located dominantly in
greenstone metamorphosed felsic to intermediate volcano-sedimentary rocks at or near the contact
with granitoid (diorite/granodiorite) intrusive rocks. The structurally controlled mineralization cuts
across all rock types, except for late mafic cross-cutting dikes (less that 10% by volume of the total
rock volume), and thus the mineralized structural zones define the modeled domains, not lithologies.
Lithology wireframes were not constructed as the gold copper mineralization is cross-cutting. The
geological model is therefore composed of oriented grade shells around the mineralization defined in
drilling and from limited trench sampling, and represent the structurally controlled zones of
veinlet/stockwork Au-Cu mineralization.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 92/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 77
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
9 ExplorationExploration carried out at the Toroparu from 2003 to 2012 is briefly described in Section 6.0 (History)
of this report. For detailed information about ETK/Sandspring exploration activities prior to 2011 the
reader is referred to previous NI 43-101 Technical Reports that are publically filed on SEDAR byP&E and Sandspring listed in the References Section 27 of this report (P&E, 2009, 2010 and 2011).
This Section 9 is devoted to discussion of the exploration programs of Sandspring during 2011 and
2012; in particular, drilling that has been completed since P&E and Sandspring completed the PEA
NI 43-101 Technical Report dated March 12, 2012 (P&E, 2012).
9.1 Exploration – 2011 and 2012
Up to the end of 2010 all exploration was focused on the Toroparu deposit and immediate
surrounding areas. At the end of the 1st quarter of 2011 an important exploration campaign was
launched with a main objective to test the gold potential of the Company’s 1000 km² Upper Puruni
Concession. This program was consisting of systematic regional and semi-regional geochemistrysampling, geological mapping, ground geophysics and reconnaissance exploration drilling.
Geochemistry (Saprolite) Sampling
During 2011 and 2012 a total of 7,390 samples were collected (Table 9.1.1). A saprolite sample is
taken by hand auger (3 1/4 inch diameter) at a depth of 1 to 3 m, below the soil or lateritic crust or
alluvial layer. Sampling is carried out following a regular grid pattern of 1000 m x 100 m in the
regional surveys, and 400 m x 50 m or 200 to 250 m x 50 m for the semi-detailed and detailed
surveys, respectively. Locations of hand auger holes are recorded by a Garmin handheld GPS.
Blank and standard QA/QC samples are inserted. Duplicate samples are prepared in the field
(sample splitting). The samples are sent for analyses to the Acme Vancouver laboratory for ICP 34
elements 1F03 (30 g samples). As of December 2012, approximately 400 km² were covered withsaprolite auger sampling within the concession lands.
Table 9.1.1: Saprolite Sampling in 2011 and 2012
Source: P&E, 2013
Saprolite Geochemistry sampling
Zone Total in 2012 Total in 2011 To tal
Ameeba 258 894 1152
Toroparu 555 149 704
Sona Hill (Toroparu Creek) 348 0 348
Puruni 540 1028 1568
Manx‐Timermans 230 289 519
Red Dragon 603 1997 2600
Makapa
(north
Ameeba) 499 0 499Total samples collected 3033 4357 7390
Blank 187
Duplicate 176
Standard 197
Total samples analyzed 7950
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 93/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 78
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
A total of 10 gold anomalies have been detected, which form a cluster around the Toroparu deposit
(Figure. 9.1.1).
Exploration drilling, primarily RC drilling, was carried out on the most prospective anomalies:
Ameeba, Toroparu W, Red Dragon North, Road, and Sona Hill.
Geological Mapping
The Upper Puruni concession is located in a poorly understood early Paleo-Proterozoic granite-
volcano-sedimentary terrain of the Guiana Shield in western Guyana. The geological knowledge is
limited due to large areas of virgin tropical forest with minimal to no road access and intense tropical
weathering. Rock outcrops are very rare, which significantly hampers systematic geological
mapping. As a result existing geological maps are quite inaccurate and lack detail. As a
consequence systematic mapping is not possible.
Sandspring has created a litho-structural sketch map of the Upper Puruni area using all available
regional data (Project and public data): airborne magnetics and radiometrics, topographic documents
(DTM, SRTM maps, JERS sat images), existing geological maps and regional geochemical data.
This contributed to the overall understanding of the regional litho-structural patterns.
Over 144 samples were collected from outcrop and road saprolite exposures. Fourteen samples
were submitted for petrographic description.
Exploration (Reconnaissance) Drilling
In 2011 exploration consisted mainly of core drilling since no reverse circulation (RC) rigs were
available in Guyana. Reconnaissance core holes were drilled at Ameeba, Timmermans and Manx,
respectively for 5,964 m, 1,116 m and 2,441 m; for a total of 9,521 m. These programs did not reveal
any significant mineralization systems on outlying targets.
An RC rig was commissioned by the end of 2011 and during the course of 2012 a 15,400 m
reconnaissance RC program was completed for several prospects (Table 9.1.2). The exploration
drilling program was designed to test the gold anomalous surface features revealed by the regional
and semi-regional saprolite geochemical sampling programs. The RC program was focused on the
following drill target areas: the Toroparu NW targets containing several zones NW of the Toroparu
deposit; the Ameeba Zone; the Red Dragon north and Road sectors; and the Sona Hill area
(Figure 9.1.1).
Table 9.1.2: 2012 RC Reconnaissance Drilling Program
Source: Sandspring, 2013
QAQC
Duplicate Blank Standard
Toroparu twin holes 3 384 5
Toroparu NW 71 5242 5
Tororparu W 7 705 10
Ameeba 29 2879 5 1754 85 58 58
Red Dragon North 21 2057 10
Red Dragon Road 15 1146 10
Sona Hill 30 2969 10 944 145 62 62
TOTAL 176 15382 7362 569 344 338
1120 170 73 74
3544 169 151 144
Samples
collectedPropsect name hole metrage
sample
interval
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 94/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 79
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Relatively small areas of mineralization were intercepted in the Toroparu NW and Ameeba areas,
sufficient to justify further test drilling. The Red Dragon Zones did not encounter significant
mineralization. RC drilling on the Sona Hill, located 5 km to the SE of Toroparu area, showed
encouraging and significant gold intercepts which required follow-up drilling. A follow-up preliminary
core drilling program of 810 m in five holes continues to show encouragement; additional core drilling
is warranted for this satellite area.
Geophysics
Combined Gradient Array IP and Magnetometer test surveys were carried out over several gold
prospects; Ameeba, Timmermans, Manx and NW of the Toroparu deposit, completing the grids of
the 2010 surveys. An additional 17 line-km were added and a total of 102 line-km of ground
geophysics were realized.
Reprocessing o f Airborne geophys ical data
Re-analyses of the 2008 airborne geophysical survey data was carried out by a geophysical
consultant. The work consisted of a basic structural interpretation of the aeromagnetics and
radiometrics and identification of the geophysical characteristics of the Toroparu deposit. This study
contributed significantly to the development of a regional exploration model.
LIDAR Survey
During the 2nd quarter of 2011 a LIDAR survey was flown over an area of 250 km² around the
Toroparu deposit zone. This technology is an airborne laser swath topographic mapping (ALSM)
system. It is amongst the only methodologies, which provides accurate and high precision
topography contour maps in tropical forest zones. The resultant topographic map has sufficient detail
for feasibility level study and engineering.
Resource Definition Infill Drilling
Project drilling previously reported in the PEA of 342 holes for 147,529 m; through hole TPD-265
included drilling through August 2011 (effective date of the PEA of January 30, 2012), as deposit
definition drilling.
An important part of the 2012 drilling activities was focused on completing the Resource Definition
drill grid over the Toroparu deposit. This targeted conversion of Inferred resources to Measured &
Indicated resources. During 2012 a total of 34,055 m in 142 holes were performed on the Toroparu
deposit area.
9.2 Relevant Exploration Work – Post-PEA Drill ing
Sandspring conducted additional drilling from September 2011 through December 2012, which isincluded in the current updated resource estimate as presented in Section 14 of this report. That
additional drilling was composed of the following:
Post-PEA drilling form August 2011 to September 2012: 166 holes for 44,096 m; through
hole TPD-426; and
A program of targeted infill drilling conducted from September through December 2012,
resulted in 48 holes for 12,163 m in both the Main Zone and the Southeast Zone.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 95/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 96/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 81
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
9.2.4 Signif icant Results and Interpretation
As of an August 2012 interim resource model, approximately 27% of the total resources within the
Main Zone and approximately 39% of the Southeast Zone within an ultimate pit shape were
classified as Inferred resources; combined representing nearly 2.0 Moz of Inferred classified material
– the target of the in-fill drilling.
Figure 9.2.4.1 shows drill collar locations and drillhole traces for all exploration drillholes at Toroparu
as of August 2012. Figure 9.2.4.2 shows the drill collar locations (without drillhole traces) for the PEA
drilling. Figure 9.4.2.3 shows the drillhole collar locations (without drillhole traces) for the post-PEA
drilling, and Figure 9.4.2.4 shows the targeted in-fill drilling collar locations (without drillhole traces).
Figure 9.2.4.5 shows a cross-section, looking horizontal along Azimuth 297, of drillholes and an
interim 2012 resource block model, color coded by classification. Targeted areas of Inferred
classification (blue) are noted as are proposed in-fill drillholes as of August 2012. Figure 9.2.4.6
shows the same cross-section showing the Au grade of the targeted Inferred classification
mineralization. Figure 9.2.4.7 shows the location of targeted in-fill drilling assay data.
Figures 9.2.4.8 and 9.2.4.9 show the results on classification and grade of blocks as a result of the
targeted in-fill drilling program, which was successful in converting a substantial amount of Inferred
mineralization to Measured and Indicated classification.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 97/340
Toroparu Gold Project,
Guyana
Figure 9.1.1
Saproli te Auger SamplingToroparu
Source: Sandspring Resources,
2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 98/340
Toroparu Gold Project,
Guyana
Figure 9.2.4.1
Toroparu – 2013 Drillhole CollarLocations and Traces – All Holes(486), Current Mineralized Shape
Source: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 99/340
Toroparu Gold Project,
Guyana
Figure 9.2.4.2
Toroparu – Drillhole Collar Location – PEA Dri ll ing through August 201
(342 holes)Source: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 100/340
Toroparu Gold Project,
Guyana
Figure 9.2.4.3
Toroparu – Drillhole Collar Location – Post PEA and Pre Targeted In -Fil
(166 holes)Source: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 101/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 102/340
Toroparu Gold Project,
Guyana
Figure 9.2.4.5
Cross-Section Showing BlockClassification and Areas of Targete
Inferred MineralizationSource: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 103/340
Toroparu Gold Project,
Guyana
Figure 9.2.4.6
Cross-Section Showing Block AuGrade and Areas of Targeted
Inferred MineralizationSource: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 104/340
Toroparu Gold Project,
Guyana
Figure 9.2.4.7
Cross-Section Showing TargetedInferred Blocks and In-Fill Drill DatSource: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 105/340
Toroparu Gold Project,
Guyana
Figure 9.2.4.8
Cross-Section showing Current BlockClassification and areas of Targeted
Inferred Mineralization that have been
Converted to Measured and Indicated
Source: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 106/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 107/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 108/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 109/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 110/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 95
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
BHID FROM TO AU g/t CU % BHID FROM TO AU g/t CU %TPD022 242 243.5 0.71 0.12 TPD022 299 300.5 2.73 0.69TPD022 243.5 245 0.65 0.19 TPD022 300.5 302 2.92 0.67TPD022 245 246.5 1.13 0.22 TPD022 302 303.5 3.43 1.37TPD022 246.5 248 0.96 0.38 TPD022 303.5 305 5.21 1.30TPD022 248 249.5 0.80 0.24 TPD022 305 306.5 3.65 1.26
TPD022 249.5 251 1.03 0.24 TPD022 306.5 308 2.30 0.68TPD022 251 252.5 0.84 0.29 TPD022 308 309.5 3.18 0.51TPD022 252.5 254 2.59 0.50 TPD022 309.5 311 1.03 0.22TPD022 254 255.5 1.55 0.54 TPD022 311 312.5 0.99 0.27TPD022 255.5 257 2.02 0.43 TPD022 312.5 314 1.10 0.30TPD022 257 258.5 1.61 0.45 TPD022 314 315.5 2.17 0.54TPD022 258.5 260 2.04 0.39 TPD022 315.5 317 1.62 0.46TPD022 260 261.5 2.31 0.46 TPD022 317 318.5 1.07 0.28TPD022 261.5 263 5.99 0.54 TPD022 318.5 320 1.18 0.34TPD022 263 264.5 27.07 0.86 TPD022 320 321.5 1.42 0.50TPD022 264.5 266 8.18 0.77 TPD022 321.5 323 0.49 0.18TPD022 266 267.5 2.25 0.48 TPD022 323 324.5 0.14 0.14TPD022 267.5 269 1.89 0.44 TPD022 324.5 326 0.57 0.16TPD022 269 270.5 3.82 0.66 TPD022 326 327.5 0.70 0.20
TPD022 270.5 272 3.61 0.58 TPD022 327.5 329 0.07 0.03TPD022 272 273.5 2.95 0.62 TPD022 329 330.5 0.06 0.02TPD022 273.5 275 2.30 0.42 TPD022 330.5 332 0.86 0.24TPD022 275 276.5 2.72 0.50 TPD022 332 333.5 0.23 0.09TPD022 276.5 278 2.19 0.30 TPD022 333.5 335 1.63 0.47TPD022 278 279.5 2.78 0.36 TPD022 335 336.5 2.74 0.38TPD022 279.5 281 2.00 0.38 TPD022 336.5 338 0.35 0.06TPD022 281 282.5 4.62 0.78 TPD022 338 339.5 0.17 0.04TPD022 282.5 284 1.26 0.26 TPD022 339.5 341 0.01 0.02TPD022 284 285.5 1.49 0.27 TPD022 341 342.5 1.44 0.27TPD022 285.5 287 1.49 0.53 TPD022 342.5 344 0.84 0.21TPD022 287 288.5 1.61 0.62 TPD022 344 345.5 0.08 0.03TPD022 288.5 290 3.63 0.68TPD022 290 291.5 3.93 0.88
Source: SRK Consulting, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 111/340
Toroparu Gold Project,
Guyana
Figure 10.1
Toroparu – Plan Map of Drillholesand Traces, Showing Mineralized
Envelope
Source: Sandspring Resources,
2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 112/340
Toroparu Gold Project,
Guyana
Figure 10.3.1
Example of Uncut Core Photograpfor Drillhole TPD-103
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 113/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 114/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 99
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
In 2005 the Santiago, Chile laboratories received ISO 9001:2000 registration with the preparation
facilities in Mendoza, Argentina and Guyana following in 2006. Acme’s Lima, Peru facility has
completed its registration audit in 2012.
In 2011 all Acme laboratories across South America were recertified under ISO 9001:2008. Their
preparation laboratory facility in Georgetown (East Coast Demerara), Guyana was recertified inJanuary 2012 after a successful audit.
Bureau Veritas completed the acquisition of AcmeLabs worldwide on February 23, 2012. The
acquisition greatly enhanced the abilities of AcmeLabs because of the capital investments made by
Bureau Veritas.
Another key benefit was the merger of AcmeLabs’ metallurgical division with that of Inspectorate’s
(also acquired by Bureau Veritas), thereby creating one of the most potent metallurgical divisions in
the industry today.
At Acme in Georgetown (East Coast Demerara), the samples are dried and the entire sample is
crushed to better than 80%, passing -10 mesh. A 250 gram split is taken and pulverized to better
than 85% passing -200 mesh. The pulps are sent to Acme in Santiago, Chile or Vancouver, British
Columbia where they are analyzed for gold and copper.
All samples were analyzed for copper by four-acid digest with AAS finish. The majority of samples
were analyzed for gold by lead collection fire assay method with AAS finish (50 gram charge). All
samples with results >10 g/t Au were further analysed by lead collection fire assay method with a
gravimetric finish.
11.5 QA/QC Procedures
Sandspring has maintained a QC program that had been initiated with drillhole TPD001. Every
sample batch prepared for analyses consists of 32 regular samples, one Coarse Duplicate, one PulpDuplicate, two Certified Reference Materials (CRM, Standards) and a blank sample.
For 2012, Sandspring initiated a check assay program using Actlabs Guyana Inc. as an outside
laboratory to provide check assays for pulp splits prepared by the primary analytical laboratory,
Acme. A total of 1,749 regular samples, 57 blanks, 58 pulp duplicates, and 56 coarse material
duplicates were prepared. Sandspring inserted 123 standards into that sample flow for a total of
2,043 check sample analyses.
11.5.1 QA/QC Resul ts
The 2012 check assay results are shown in Figures 11.5.1.1 through 11.5.1.4, which are scatter
plots of Actlabs versus Acme results, respectively for Au, Cu, Au in pulp duplicates, and Au in coarseduplicates. The results indicate no particular bias of Au or Cu between the assay labs; satisfactory
confirmation of assays.
11.5.2 QA/QC Actions
Sandspring staff in 2012 prepared monthly reports of QC samples submitted and the results of any
failures for standards or blanks, based on plots of the data against expected values and showing a
two and three standard deviation line for each standard sample value. Failures of over two standard
deviations from the expected values resulted in that sample batch being re-run.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 115/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 116/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 117/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 118/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 119/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 120/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 121/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 122/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 123/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 124/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 125/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 110
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The test program included single-pass tests at three different pressure settings in order to determine
the optimum operating parameters for the test apparatus. The test program also incorporated locked
cycle testing in order to simulate the product size distributions to be expected in an industrial sized
HPGR circuit. The results of the locked cycle testwork are summarized in Table 13.4.3.1.
Table 13.4.3.1: Summary of HPGR Test FindingsDescription Unit Value
Wet Bulk Density Kg/L 1.75Feed Particle Size, F80 mm 10Product Particle Size, P80 mm 2.3Pressure of Operation bar 60Moisture (% H2O) 3.6Dry Net Throughput t/h 1.5Circulating Load % 72.4Gross Specific Energy Requirement kWh/t 3.70Net Specific Energy Requirement kWh/t 3.06Specific Grinding Force N/mm 3.01Specific Throughput t*s/m *h-(mf ) 220Specific Throughput Rate t*s/m
3*h-(mc) 196
Ratio mc/mf 0.89
The results indicate that the sample material is amenable to the HPGR process.
13.5 Gravity Separation (ACO/LCO)
Gravity separation tests performed at Resource Development Inc. (RDi) and SGS Lakefield resulted
in Au recoveries from 13.4% to 52.1%. Grind sizes between P 80 50 µm and P80 300 µm were tested
and showed a general trend of higher recoveries at finer grind sizes. Gravity recoveries were
estimated to be about 38% for the P80 150 µm primary grind size.
The results of the three phases of gravity testwork are summarized in Table 13.5.1.
Table 13.5.1: Gravity Separation Result s Summary for Phase 1, Phase 2, Phase 2 Extension
GravityTest No.
Feed SizeP80, µm
Feed Weightkg
ProductMass
% Assays Au, g/t
Distribution%
Phase1
MC-04 300 2 Mozley Concentrate 0.07 282 32.5Knelson/Mozley Tailing 99.93 0.39 67.5
MC-05 150 2 Mozley Concentrate 0.12 189 36.5Knelson/Mozley Tailing 99.88 0.4 63.5
Phase2
50 20 Mozley Concentrate 0.03 652 31.0Knelson/Mozley Tailing 99.97 0.39 69.0
75 20
Mozley Concentrate 0.04 838 52.1
Knelson/Mozley Tailing 99.96 0.33
47.9
125 20 Mozley Concentrate 0.03 517 24.8Knelson/Mozley Tailing 99.97 0.44 75.2
175 20
Mozley Concentrate 0.03 370 13.4Knelson/Mozley Tailing 99.97 0.67 86.6
Phase2 Extension
G-51 228 2Mozley Concentrate 0.24 122 47.7Knelson/Mozley Tailing 99.8 0.33 * 52.3
G-52 149 2Mozley Concentrate 0.20 145 43.4Knelson/Mozley Tailing 99.8 0.37 * 56.6
Knelson/Mozley tailings is calculated from cyanidation test
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 126/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 127/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 128/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 129/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 114
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
test ACO-02 produced a higher grade concentrate of 25.3% Cu, 88.5 g/t Au, 224 g/t Ag and 26.1% S
at recoveries of 73.9%, 59.2%, 55.1% and 62.5%, respectively.
The ACO Composite was subjected to a six cycle LCT. The test was performed using 4 kg charges
of the ACO Composite gravity tailings ground to P80 156 µm (from test G-5). The reagents used
included PAX in conjunction with the promoter Aerofloat 208. In the two cleaning and cleanerscavenger stages, CMC was used as a non-sulfide gangue depressant. Lime was used to modify the
pH and MIBC was used as a frother and added on an as-required basis.
The results from the LCT test are shown in Table 13.6.4.2. The Cu concentrate obtained from the
last three stages (D to F) produced a concentrate containing 21.0% Cu, 56.0 g/t Au, 180 g/t Ag and
20.9% S at recoveries of 91.3%, 67.2%, 65.0% and 78.4%, respectively. The first cleaner scavenger
tailing contained 0.091% Cu, 0.77 g/t Au and 2.1 g/t Ag and constituted 10.6% of the total mass,
12.6% of the Au, and 10.2% of the Ag.
Table 13.6.4.2: Locked Cycle Test Results
Product
Wt Assays, %, g/t % Distribution
g
% Cu Au Ag S Cu Au Ag SCopper Con 190 0.8 21.0 56.0 180 20.9 91.3 67.2 65.0 78.41st Cl Sc Tailings 2599.6 10.6 0.091 0.77 2.1 0.34 5.4 12.6 10.2 17.3Rougher Tailings 21718.4 88.6 0.007 0.15 0.6 0.01 3.3 20.2 24.8 4.3Head (Calculated) 24508.0 100 0.18 0.65 2.1 0.21 100 100 100 100
An examination of the stage-by-stage results indicated that the Cu and S grades dropped abruptly
for the last two stages of the test (E & F), due to a build-up of non-sulfide gangue. From this
observation, it appears that the added CMC to the cleaning circuit was not sufficient or an extra
stage of cleaning should be applied.
Au and Ag recoveries from gravity separation test (G-5) combined with LCT at P80 150 µm was
calculated to be 79.1% Au and 69.2% Ag. The results can be found in Table 13.6.4.3.
Table 13.6.4.3: ACO Combined Result s from Gravit y Separation and LCT Tests
Grind SizeCampaign
Gravity recovery , % Cleaner Flotation, % Comb. Recovery, %
Au
Ag
Au Ag Au Ag
150 µm 38.5 11.9 67.2 65.0 79.1 69.2
13.6.5 Gold Ore with Low Copper (LCO)
The LCO metallurgical testwork program involved testing of a Master Composite and the four
Variability Composites (A to D) to evaluate response to gravity separation, rougher flotation, and
cyanidation of gravity separation concentrate. Evaluation of the effect of grind size on metallurgical
performance was limited during this testwork program and included three scoping rougher flotation
tests at grind sizes of 125, 175 and 225 µm to confirm the findings from the ACO test program.
Three scoping rougher flotation tests were performed on the three gravity tailings produced at three
different P80 grind sizes to observe the effect of grind size on rougher flotation performance.
The recovery of copper and gold increased as a function of finer grind size, while the recovery of
silver did not display this trend. The copper recovery increased from 93.6% at P 80 252 µm to 97.2%
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 130/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 115
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
at P80 125 µm. Similarly, the gold recovery increased from 79.7% at P80 252 µm to 84.3% at P80 125
µm. In order to compare results of these tests to the testing of the ACO sample, a P 80 grind size of
150 µm was selected for the subsequent bulk rougher flotation tests.
A total of eight bulk rougher flotation tests were performed on the gravity tailing produced from the
Master and Variability Composites, all at the P80 grind size of 150 µm. The objective of the tests wasto produce concentrate for the subsequent cyanidation testwork.
The results show that the recovery of copper ranged from 97.0% to 92.4% for the different
composites. The recovery of gold shows significant variation between samples from as low as 65.7%
to as high as 80.2%. The average of three tests of the Master Composite showed a gold recovery of
75%.
The overall combined gravity and flotation gold recovery from the Master and Variability composites
is shown in Table 13.6.5.1.
Table 13.6.5.1: Combined Gravity and Flotation gold Recovery for the LCO Composites
Composite Au GravityRecovery, % Au Flotat ionRecovery, %* Au Comb.Recovery, %
Master 67.5 75.1 91.9Ore A 42.5 69.0 82.2Ore B 39.0 80.8 88.3Ore C 57.9 68.1 86.6Ore D 46.2 76.3 87.3
*Average of all applicable tests
13.7 Cyanide Leaching (ACO/LCO)
Cyanide leaching for the 2011 test program conducted at SGS Lakefield was split into three separate
phases. Subsequent testwork in 2012 by SGS was conducted on both ACO and LCO composites.
13.7.1 Phase 1
Phase 1 cyanidation testwork was presented in two separate flowsheet processes, first was the
cyanidation of whole ore (P80 target of 150 µm and 75 µm) and the second was rougher concentrate
cyanidation.
The cyanidation testwork involved three whole ore tests, one at P80 150 µm and two at P80 75 µm.
One of P80 75 µm leaches was performed as a CIL test while the other did not have any carbon
added. Following a 48-hour leach residence time, extractions of 90.0% Au at P80 160 µm, and 89.1%
Au at feed P80 of 102 µm were observed. The CIL had a total extraction of 91.1% Au, with 88.7%
contained in the carbon and 2.4% remaining in the barren leach solution. The cyanidation testingalso included leaching of rougher concentrate in two tests where one was tested as received while
the other was reground. Extraction of 96.4% and 97.8% Au was achieved from the as received and
reground samples respectively. Cu extraction and cyanide consumption increased from 18.9% Cu
and 14.7 grams of NaCN for the as received sample test to 29.6% Cu and 27.4 grams of NaCN for
the reground sample. It appears that regrinding of the sample may have led to increased leaching of
copper resulting in a higher copper concentration in solution.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 131/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 116
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
13.7.2 Phase 2
The cyanide leaching in Phase 2 included leaching of four separate products. The first set of leach
tests was performed on the gravity tailings resulting from four target grinds. Following direct
cyanidation of the gravity tailing, the leach residues were combined and then split for performing two
CND tests that were completed to a weak acid dissociable (WAD) content of 0.5 and 2.0 ppm. TheCND test residues were then tested for recovery of Cu using flotation.
The second set of leach tests was performed on rougher tailings following the rougher flotation of
each size campaign.
The third set of leach tests was performed on the rougher concentrates from the 75 µm campaign.
The rougher concentrate was split into thirds and the effect of regrind was evaluated. The three
leach residues were then combined and a CND test was completed to a WAD content of 0.5 ppm
after which the recovery of Cu using flotation was again examined.
The fourth set of leach tests was performed on Mozley vanner gravity concentrate from the 75 µm
campaign.
The purpose of this highly integrated testwork program was to evaluate the effect of grind size as
well as to evaluate the effect of the processing flowsheet on the recovery of Au and Cu.
The data shows direct cyanidation of the gravity tailing considerably improves Au recovery with an
increase of 8.5%. Alternatively, the recovery of Cu is shown to be much improved through rougher
flotation.
Despite the significant improvement in Au recovery from direct leaching the capital and operating
costs of such a process is expected to be significant due to the requirement of CND to allow
subsequent recovery of Cu. Therefore, the Phase 2 Extension program evaluated extension of the
flotation process to evaluate cyanidation of cleaner concentrate and cleaner tailing thus eliminating
the need for the intermediate CND step between cyanidation and flotation.
13.7.3 Phase 2 Extension
The cyanide leaching testwork in the Phase 2 Extension was performed on three separate process
streams. The first was the direct cyanidation of the gravity tailings resulting from two target grind
sizes P80’s of 228 μm and 149 μm. The final Au extraction value for both tests was approximately
89% which indicates grind size has little effect in Au leaching of the samples.
The second was cyanidation of cleaner concentrate and cleaner tailing from MC-32 to MC-35. The
results showed that cyanidation of the cleaner tailing was excellent with an Au extraction of 88.2%,
while cyanidation of the cleaner concentrate was poor with an Au extraction of 59.0%.
The third cyanidation test was performed on the cleaner scavenger tailings from flotation tests MC-
37 to MC-40. The result showed the final extraction of gold was about 81%.
Flotation tests MC-37 to MC-40 investigated the possibility of deporting a greater proportion of the
Au to the cleaner tailing using a larger dosage of lime to increase the pH further. The results showed
that the proportion of Au reporting to the cleaning circuit increased from 3% to approximately 5%. It
is possible that the proportion of Au reporting to the cleaner tailing could be further increased by an
even greater lime dosage, or reduced collector dosage. Also, performing a locked cycle test may
increase the proportion of Au in the Cleaner Scavenger Tail.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 132/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 117
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
13.7.4 Locked Cycle Test Cleaner Tailing Cyanidation (ACO)
One Cyanidation test was performed on the cleaner tailings obtained from the locked cycle test
conducted with the ACO composite. The amount of copper and gold reporting to the first Cleaner
Scavenger Tailing in this test was 5.4% and 12.6% respectively. The extraction of gold and silver
was 72% and 64% respectively and was accompanied by a copper extraction of 34%.
The overall recovery of the gravity separation coupled with cleaner flotation and cyanide leaching of
the Cleaner Tailing is summarized in Table 13.7.4.1.
Table 13.7.4.1: ACO Gravity , Cleaner Flotation, and Cleaner Tail Leach Summary
Grind SizeCampaign
Gravity Cleaner Con Cleaner tail Cleaner Tail CN Combined Au Ag Au Ag Au Ag Au Ag Au Ag
150 µm 38.5 11.9 67.2 65.0 12.6 10.2 72.2 64.2 85.4 74.9
From comparison of the results of the ACO test program, cyanide leaching of the gravity separation
tailing offers higher gold and silver recovery than rougher and cleaner flotation combined with
leaching of the cleaner tailing. However, the cyanide consumption and copper extraction from the
cleaner flotation processing route is 0.11 kg/t and 1.8% Cu respectively. This is considerably lower
than the gravity tailing leaching route that resulted in cyanide consumption and copper extraction of
1.24 kg/t and18.0% Cu respectively.
13.7.5 Gravity Concentrate Intensive Cyanidation (ACO)
The response of the gravity concentrate stream, gravity tailings stream, and cleaner scavenger
tailings stream to cyanide leaching was examined in a series of tests.
The Mozley concentrate obtained from gravity tests G-1 to G-4 were submitted for intensive
cyanidation. The tests were performed at 5% solids with 20 g/L of NaCN for 24 hours.
Au extraction was 99% for all cases and Ag extraction was 97%. Results show that the feed size has
no effect on leaching recovery.
The gravity tailings of gravity test G-1 to G-4 at four P80 sizes were submitted for bulk cyanidation
tests. The tests were performed at 40% solids with 0.5 g/L of NaCN as Carbon-in-Pulp (CIP) tests in
which the carbon was added after 48 hours of leaching. Carbon contact time was about six hours.
The final Au extractions at 54 hours ranged from 71% for CN-12 at P 80 240 μm to 87% for CN-5 at
P80 72 μm and CN-10 at P80 179 μm. Overall, the gold extraction occurred in a narrow range and
showed a general trend of an increase in gold extraction with decreasing feed size.
The final Ag extractions at 54 hours were distributed in a very narrow range from 72% for CN-12 at
P80 240 μm to 77% for CN-5 at P80 72 μm and CN-7 at P80 117 μm.
The final copper extractions for all the leaches ranged from 16% for CN-9 at P 80 166 μm to 20% for
CN-7 at P80 117 μm. The copper extraction for all tests was low and does not appear to be
influenced by varying feed size.
The combined extraction of gold and silver from the gravity separation stage and cyanide leaching
ranged from 82% for CN-11 and CN-12 (both P80 240 μm) to 94% for CN-5 at P80 72 μm for gold and
from 75% for CN-12 at P80 240 μm to 80% for CN-5 at P80 75 μm for silver.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 133/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 134/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 119
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The copper extraction for all the leaches did not exceed 14% at 54 hours. The iron extractions were
very low and did not exceed 1.5%; however, there was still a significant amount of iron present in
solution which resulted in high cyanide consumptions.
The combined recovery of gravity separation, rougher flotation and cyanidation of the rougher
concentrate for gold and silver are shown in Table 13.7.8.1. The combined recovery for gold rangedfrom 79% (CN-32R) to 85% (CN-31) and for silver ranged from 30% to 50% for CN-35 and CN-33
tests, respectively.
Table 13.7.8.1: LCO Combined Result s from Gravity Separation, Rougher Flotation andRougher Concentrate Leaching
CN TestNo.
OreType
Recovery, %
Gravity
Gravity TailFlotation
Leach Combined*
Au Ag Au Ag Au Ag Au Ag
CN-30 Master 50 11.4 75.7 50 92 74 84.8 44.2CN-31 Master 50 11.4 77 49.2 92 72 85.4 42.8CN-36 Master 50.2 12.2 72.7 48.2 93 60 83.9 37.6
CN-36R Master 50.2
12.2 72.7 48.2 95 81
84.6
46.5CN-32 A 42.5 8.8 72.3 41.2 95 66 82.0 33.6CN-32R A 48.1 11 65.7 35.8 91 62 79.1 30.8CN-33 B 38.8 11.2 80.8 55.1 91 80 83.8 50.3CN-34 C 57.9 4.1 68.1 45.6 94 82 84.8 40.0CN-35 D 46.1 11.2 76.3 29.8 89 70 82.7 29.7
*Leach of rougher float concentrate
13.7.9 Comparison of Cyanide Leaching of Gravity Tailing and Flotation Products for ACO and LCO
The main objective of the ACO and LCO testwork program was to compare the performance of direct
cyanide leaching of the gravity tailing and cyanide leaching of a flotation product. The flotation
product of interest was flotation cleaner scavenger tailings for ACO program while it was a rougher
concentrate for the LCO program.
Tables 13.7.9.1, 13.7.9.2, and 14.7.9.3 show comparisons of the overall gold recovery for three
different combinations for ACO testwork program:
Table 13.7.9.1: Overall Gold Recovery for ACO Composi te, Gravity and Gravi ty TailingCyanide Leaching
GrindSize
Campaign
Au Recovery, %Gravity Gravity Tail CN
Leach*
Combined
Au
Ag
Au Ag Au Ag75 µm 54.9 12.7 86.3 76.0 93.8 79.0
125 µm 43.9 8.3 83.3 76.4 90.6 78.3175 µm 39.1 10.5 82.8 73.8 89.6 76.5225 µm 37.3 9.6 71.6 73.8 82.2 76.3
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 135/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 120
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 13.7.9.2: Overall Gold Recovery for ACO Composi te, Gravity and Gravi ty TailingRougher Flotation
Grind SizeCampaign
Au Recovery %
Gravity recovery, % Flotat ion Recovery, %* Comb. Recovery, %
Au Ag Au Ag Au Ag
75 µm 54.9
12.7 77.8 78.8 90.0 81.5 125 µm 43.9 8.3 80.6 81.0 89.1 82.6
175 µm 39.1 10.5 80.5 81.1 88.1 83.1
225 µm 37.3 9.6 76.1 77.9 85.0 80.0
Table 13.7.9.3: Overall Gold Recovery for ACO Composi te, Gravity , Gravity Tailing CleanerFlotation and Cleaner Tail cyanide Leaching
Grind SizeCampaign
Au Recovery %
Gravity Cleaner Con Cleaner tailCleaner TailCN Leach
Combined
Au
Ag
Au Ag Au Ag Au Ag Au Ag
150 µm 38.5 11.9 67.2 65.0 12.6 10.2 72.2 64.2 85.4 74.9
The results show that while the gravity separation and leaching of the gravity separation tailing for all
grind sizes offers higher overall gold recovery, it is not a large enough difference to compensate for
the loss of saleable Cu and the increased cyanide consumption.
Similarly Tables 13.7.9.4 and 13.7.9.5 show comparisons of the overall gold recovery for two
different combinations for LCO testwork program:
Table 13.7.9.4: Overall Gold Recovery for LCO Composi tes, Gravity and Gravity TailingCyanide Leaching
Sample
Au Recovery, %
Gravity Gravity Tail CN Leach Combined Au
Ag Au Ag Au Ag
Master* 58.6 7.9 88.4 58.4 95.2 61.7Ore A 39.2 7.3 94.7 36.2 96.8 40.7Ore B 47.7 12 90.9 51.3 95.2 56.9Ore C 60.8 11.6 92.1 42.2 96.9 48.7Ore D 37.7 9.8 87.8 29.0 92.4 36.0
Table 13.7.9.5: Overall Gold Recovery for LCO Composi tes, Gravity and Gravity TailingRougher Flotation and Rougher Concentrate Cyanide Leaching
Sample
Au Recovery,%
Gravity Gravity Tail Flotation Ro Conc Leach Combined
Au
Ag
Au Ag Au Ag Au AgMaster* 50.1 11.8 75.1 49.1 92.7 71.4 84.9 42.7Ore A* 45.3 9.9 69.0 38.5 92.9 64.1 80.4 32.2Ore B 38.8 11.2 80.8 55.1 91.4 79.8 84.0 50.3Ore C 57.9 4.1 68.1 45.6 94.1 82.5 84.9 40.1Ore D 46.1 11.2 76.3 29.8 89.1 70.3 82.8 29.8
Similar to the ACO program, the overall gold recovery for the LCO samples is also higher for the
gravity separation and leaching of the gravity separation tailing option. However, the cyanide
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 136/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 137/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 122
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 13.7.9.9: Copper Extraction and Cyanide Consumption for Rougher ConcentrateLeaching of LCO
ProductRougher Concentrate CN Leach Corrected for % Wt and Cu dist .
Cu Extraction, %
CN Consumption, kg/t
Cu Extraction, %
CN Consumpt ion, kg/t
Master* 10.8
13.1
10.5
1.09
Ore A* 9.6 8.77 8.9 0.72
Ore B 12.7 13.1 12.2 1.11
Ore C 14.5 11.0 13.6 0.75
Ore D 6.6 7.93 6.4 0.52
*Average of all tests
13.8 Saprol ite Test Work Program 2012-2013
The metallurgical test program conducted by Inspectorate 2012 and 2013 focused on the extraction
and recovery of gold from saprolite. The testwork included gravity separation, cyanidation, flotation,
and cyanide detoxification.
The bulk of the work was done on a Master Composite that represents the average grade of the
material and which is derived from drillholes that are spatially represented throughout the deposit.
Approximately 150 to 200 kg was the intended sample size to ensure that sufficient material is
available in the event that repeat or confirmatory work is required.
A set of variability composites were provided that represent low, medium and high grade material
and spatial variability throughout the deposit. Samples size was about 40 to 50 kg per sample to
ensure that sufficient material is available for possible repeat or confirmatory work. All variability
samples were collected from ½ core intervals of archived drill core; most of the samples were from
drillholes completed in 2011 and 2012.
13.8.1 Gravity Separation Testwork
Both the coarse and fine saprolite samples were subject to gravity concentration using a 3 inch
Knelson® centrifugal concentrator followed by a Mozley vanner. The gravity test for the fine saprolite
sample was performed on the sample without any prior processing. The coarse saprolite sample was
ground to P80 200 µm prior to the test. Gold recoveries for the fine and coarse samples were
approximately 50% and 27%, respectively. Intensive cyanide leaching of the gravity concentrates
resulted in recoveries of 97% from both samples.
13.8.2 Flotation Testwork
Four flotation tests were performed on the fine saprolite sample to investigate different reagentschemes on the recovery of Au.
Recoveries for the fine saprolite sample were between 70% and 80% for all four tests.
Four additional tests were performed on the coarse saprolite sample to investigate the impact of
grind size on the recovery of Au. The four different P80 grind sizes used were 270 µm, 209 µm, 142
µm, and 88 µm. Results showed that a decreasing grind size had a positive effect on the recovery of
Au, with recoveries up to 86.7% for the finer grind size of 88 µm.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 138/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 123
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
13.8.3 Cyanidation Testwork
Cyanide leach and CIL tests were performed on the saprolite fines sample to investigate the effect of
cyanide dosage in both leach and CIL circuits. Three separate NaCN dosages (0.25 g/L, 0.5 g/L, and
1.0 g/L) were tested on both the leach and CIL tests. Results from these test showed that NaCN
dosages have no effect on Au recovery, with all three dosages achieving the same recoveries. Theleaching method did appear to affect recoveries, with the CIL tests achieving a slightly higher
recovery of 98% versus the leach recovery of 96.8% (nominally the same).
Intermediate samples were taken from the leach tests to examine the leaching kinetics of the
sample. The tests showed that the leaching kinetics of the sample were slow, with the full 72 hours
needed to approach maximum recoveries. Figure 13.8.3.1 shows the Au leaching kinetics curve for
the sample.
Cyanidation tests were also performed on the coarse saprolite sample to investigate the grind-
recovery behavior of the sample. Four different grind sizes (P80 277 µm, 213 µm, 129 µm, and 88
µm) were tested. The tests show that the sample requires grinding to a P80 of at least 213 µm in
order to facilitate acceptable recoveries. Grinding the sample from P80 213 µm to P80 129 µm showedslight improvement to the final recovery, indicating that the optimal grind size is between P 80 213 µm
and P80 129 µm. The Au leaching kinetics curve for different grind sizes is shown in Figure 13.8.3.2.
One cyanide detoxification test was performed on the tailings from one of the CIL tests for the
saprolite fines using the air/SO2 process. Results from the test show that the air/SO2 process can
detoxify the tailings to achieve effluent standards.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 139/340
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0 20 40 60 80 100 120 140 160 180
R o u g h e r T a i l i n g s G r a d e
( % ,
g / t )
Sample k80 (µm)
Cu
Au
Au
Cu
Toroparu Gold Project,
Guyana
Figure 13.6.2.1
Effect of Sample P80 on RougherTailings Grade of Au and CuSource: TetraTech, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 140/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 141/340
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80
R e
c o v e r y ,
%
Leach Time, hours
Au Cyanide Leach Kinetics
277 um 213 um 129 um 88 um
Toroparu Gold Project,
Guyana
Figure 13.8.3.2
Au Cyan ide Leach Kinetics fo rCoarse Saproli teSource: TetraTech, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 142/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 143/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 144/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 145/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 130
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Main Eastern lens, containing the larger part of the resource and displaying in its core zone
the highest average Au and Cu grades;
Main Western lens, marked by lower average gold grades and very low grades of Cu; and
SE lens, carrying mainly gold mineralization, forms a near-by satellite body, 1.2 km SE of the
main eastern lens.
On a deposit scale, relatively dense fracture networks seem to occur by preference in elongated E-W
oriented and west plunging lenticular bodies, which, in particular in the Main Eastern and the SE
Zones appear as higher grade mineralization features. Dense fracturing associated with higher grade
gold and copper mineralization seems to develop more or less along the intrusive contact and cross-
cuts lithologies. Around these higher grade core features and towards the borders of the deposit,
fracturing intensity gradually decreases and gold and copper grades drop. The Main Zone lenses are
surrounded by a larger, 2.75 km long and 200 to 400 m wide, WNW oriented mineralization envelop,
which is marked by scattered medium-to-low grade gold and barely any copper mineralization. A
similar structure, but less well expressed because of lower grades, has been detected in the Main
West part of the deposit. The objective of a 2012 re-logging exercise was to homogenize the
geological descriptions and develop a reliable geological model including the definition of geological
limits for the resource modeling.
In spite of an improved knowledge of the geological framework, it was difficult to identify clear litho-
structural boundaries for the mineralization system and limits to the mineralization have been
modeled as essentially grade “shells”. These were developed with a sequence of steps incorporating
interpreted geology (extent, shape, structures) as controls. A three dimensional grade contour
threshold was selected which produced a coherent geometry and a geologically realistic
representation of the overall mineralized extents of the deposit. Preferential orientation of the
continuity of mineralization (anisotropy) was interpreted as having a variation related to these overall
geometries. Anisotropy models were constructed and used not only as geologic controls for the
assignment of grades but also for the delineation of mineralized and non-mineralized zones internalto the overall domain wireframes.
14.3.1 External Domain Envelope
Envelopes were constructed by Sandspring to represent the overall limits of potential possible
mineralization using Leapfrog® and GEMS software and all drillhole data, the Toroparu domain
boundaries, and grade boundary interpretation from visual inspection of drillhole sections. Four
domains were created named Fresh Rock Main, Saprolite Main, Fresh Rock South East, and
Saprolite South East. The South East Zone domains were constructed separately as the zone is
geographically separated from the Main Zone by 1.2 km. These domains were created with
computer screen digitizing on drillhole sections and plan views in Gemcom by Sandspring. Theoutlines were influenced by the selection of mineralized material above 0.2 g/t Au in fresh rock and
saprolite that demonstrated zonal continuity along strike and down dip. In some cases mineralization
below 0.1 g/t Au was included for the purpose of maintaining zonal continuity. Smoothing was
utilized to remove obvious jogs and dips in the domains and incorporated a minor addition of Inferred
mineralization. This exercise allowed for easier domain creation without triangulation errors from
solids validation. On each section, polyline interpretations were digitized from drillhole to drillhole but
not typically extended more than 20 m into untested territory. Minimum constrained true width for
interpretation was 3.0 m. The interpreted polylines from each section were “wireframed” in Gemcom
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 146/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 131
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
into three-dimensional domains and are displayed in plan and perspective on Figures 14.3.1.1 and
14.3.1.2, respectively.
14.3.2 Anisotropy Model
A visual examination of the distribution and locations of drillhole intercepts indicates that thepreferential orientation of the continuity of mineralization (anisotropy) appears to be related to the
overall geometry of the elongated mineralization. Surfaces (digital terrain models) were created by
Sandspring from polylines following the higher grade assay occurrences throughout the entire
mineralized envelope and are displayed in red on Figure 14.3.2.1. These interpretations are used as
controls for grade estimation as discussed in section 14.10 and also acted as controls for the further
refinements of the mineralized shells internal to the overall shape.
14.3.3 Internal Domain Envelopes
With added relatively closely spaced information from the targeted infill drilling program, delineation
of non-mineralized (or extremely low grade, below 0.2 g/t Au) zones internal to the overall domain
wireframes was possible for the Main Zone and portions of the South East. Within the overall
mineralized envelope the Toroparu low grade domain boundaries were determined based on
lithology, structure and grade boundary interpretation from visual inspection of drillhole sections.
These domains were created by Sandspring with computer modeling in LeapFrog® 3D using
constant (ordinary kriging) and taking into consideration statistically calculated nugget effect for this
deposit. The outlines represent mineralized material below 0.2 g/t Au. The raw material for this
modeling exercise was selected based on filtering the existing assay database within the mineralized
envelope and creating two datasets: first above 0.2 g/t Au, and second below 0.2 g/t Au. The first
dataset was used to create internal higher grade wireframes following the orientation of the
anisotropy model and structural components containing higher grade material. The second (low
grade material) dataset was used to fill the gaps between the higher grade and the overall domain
wireframe. As a result a body that reflects the three-dimensional spreading of the low grade was
developed. Subsequently a series of volume filters were used to eliminate small bubbles and
volumes smaller than a block-size in the model. Figure 14.3.3.1 is the non-mineralized component of
the Main Zone that is internal to the overall mineralization displayed on Figure 14.3.2.1.
The Domain wireframes were imported into the Datamine Studio3® mining software package. SRK
has reviewed these wireframes and considers them appropriate; the saprolite/fresh rock boundary is
essentially a sub-topographic-parallel surface while the areal extent is a modified (or smoothed)
grade shell at a 0.2 g/t Au cut-off. Grade shells were constructed for alternative (higher) cut-offs as
well however for the purpose of a “global in-pit” resource, identifying solely a single global population
of grades, the 0.2 g/t shell was selected as reasonable and realistic. Figure 14.3.3.2 and 14.3.3.3 are
representative model plans and sections displaying the final delineation of mineralization. Internal
non mineralized units are intended to be of sufficient size to represent zones that can be differentially
mined with the anticipated methods.
14.4 Domain Analysis & Grade Capping
All assays were assigned relevant domain codes via an intersection with the wireframes. Assay
statistics are reported for both the fresh rock and saprolite mineralized domains for both Au and Cu
on Table 14.4.1.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 147/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 132
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 14.4.1 Assay Summary Statis tics by Domain
Item Au g/t assays Cu % assays
Al l Fresh Saprol ite Al l Fresh Saprol ite
Number of Values 42,203 39,593 2,610 42,203 39,593 2,610Maximum Value 562.600 562.600 48.600 4.658 4.658 1.862
Minimum Value 0.005 0.005 0.005 0.000 0.000 0.000Mean 0.807 0.815 0.678 0.078 0.078 0.070Variance 20.194 21.306 3.307 0.014 0.014 0.013Standard Deviation 4.494 4.616 1.818 0.118 0.118 0.113Coefficient of Variation 5.57 5.66 2.68 1.52 1.51 1.61
Source: SRK, 2013
Figures 14.4.1 and 14.4.2 are lognormal cumulative frequency (CF) distribution diagrams for Au and
Cu for the fresh rock and saprolite domains. Using these lognormal probability diagrams as a guide,
in conjunction with an examination of the distribution of drillhole data, “thresholds” were selected for
each domain type; an inflection point was selected to identify assays that are to be considered
“outliers” to the general distribution and “capped” or set back to the defined threshold. The thresholds
selected are tabulated on Table 14.4.2.
Table 14.4.2: Assay Capping Thresholds
Item Au g/t Cu %
Fresh Assay Cap 15.00 1.10Number Of Values Affected 113 29Maximum Assay Value 562.60 4.66Saprolite Au g/t Cu %
Assay Cap 8.00 0.50Number Of Values Affected 19 31Maximum Assay Value 48.60 1.86
Source: SRK, 2013
Alternative methods to the capping applied could be developed to mitigate the impact of outliers and
allow their inclusion in the assay data population; multiple populations potentially could be defined
representing different styles of mineralization. However, given the intent of modeling the primary
mineralization as a single population for the deposit, the raw assays were capped or “set back” to the
respective threshold values noted above prior to compositing. Table 14.4.3 summarizes the statistics
for capped assays; as expected there is a reduction of the coefficient of variation (CV) for both
grades within all populations. For fresh rock the CV for Au was reduced from 5.66 for uncapped to
1.86 with a decline in the standard deviation.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 148/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 149/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 134
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Wax sealing of the core was not done, and is not necessary, as the core in fresh rock is solid dense
rock with no porosity and very few open fractures.
SRK was provided an Excel Spreadsheet; Master_Bulk_Density_November_24, 2012, which has a
total of 2815 bulk density measurements for core data from various lithologies and drill depths. There
are 277 measurements that have a designation as saprolite, 213 defined as other specific rocktypes, and 2325 measurements for which the rock type is not specified.
SRK considers the amount and quality of bulk density data is sufficient for use in resource estimation
at feasibility level.
The data were examined in three ways; globally for the entire data set, by rock type, and by drill
depth. Figure 14.6.1 shows the histogram distribution of all the data, clearly indicating a tri-modal
population; saprolite (1.0 to 2.1), transition (2.1 to 2.5), and fresh rock (2.5 to 3.9). The transition data
represent in part intermediate densities of the true transition from saprolite to fresh rock, but also
includes some 161 measurements of lower density rock than the average fresh rock (2.75), yet the
data occur at depths of 100 m to 850m and are therefore not saprolite, or saprolite-fresh transition
rock.
An examination of bulk density data by the lithology codes results in the summary in Table 14.6.1
Table 14.6.1: Bulk Densit y by Major Rock types
Type No. Low High Ave Mod. Ave Comment
Saprolite 277 1.45 2.97 1.93 1.88 Ignore 1 @ 1.45 and 18 at 2.5 to 3.0
All other specifiedRock Types
213 2.25 3.92 2.77 2.76 Ignore 1 @ 2.25 and 4 above 3.3
Non-specifiedRock type
1325 1.01 3.98 2.69Presumed to be a mix of saproliteand fresh rocks of all types
Source: SRK, 2012
Individual spread sheet tabs for specific rock types present the following bulk density data Table
14.6.2.
Table 14.6.2: Bulk Densit y Data by Rock Code
Type (Rock Code) No. Low High AverageID, MD 9 2.25 2.90 2.74GB 7 2.84 3.04 2.97GRDR 26 2.70 2.80 2.73
AI 56 1.01 2.96 2.75MIV, P-MIV, FIV, F-MIV 111 2.64 3.92 2.78SAP 28 1.52 2.07 1.81
Source: SRK, 2012
SAP = Saprolite, is defined in the geological model as a separate solid shape, and GB = Gabbro,
which are dikes and are not separately modeled as the volumes are considered minimal. Fresh rock
lithologies range from 2.73 to 2.78 with the exception of Gabbro at 2.97.
In summary Table14.6.3 is a comparison of the density data currently in use in the resource block
model versus the averages as determined by the histogram and the specific lithologies.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 150/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 135
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 14.6.3: Summary of Bulk Density Data
Type Current Block ModelDatabase Histogram
InterpretationDatabase by
Major Rock TypeData by
Specific Rock type
Saprolite 1.84 1.85 1.88 1.81
Transition Not modeled2.30 (2.1 to 2.5),
(6-7% of the data)N/A N/A
Fresh Rock 2.76 2.75 2.76 2.77 (2.73 to 2.97)
Source: SRK, 2012
True transition rock from saprolite to fresh rock is not modeled, but is estimated at 0 to perhaps 5
meters in thickness and insignificant to the modeling, as are the gabbro dikes of nearly 3.0 density.
SRK used the two average bulk densities, 1.84 for saprolite and 2.76 for fresh rock in the resource
model; interpolation of density data was not deemed necessary.
It is estimated that 10% or less of the total volume of mineable material would be affected by using
either a mid-range density of 2.1 to 2.5 or the higher density for gabbro at 2.97, and in fresh rock
these densities will likely result in a negligible net change in tonnage
14.7 Block Model
SRK constructed block models using the Datamine Studio3® mining software package, for the
Toroparu deposit with data provided by Sandspring. The South East Zone, being approximately
1.2 km offset from the Main, was modeled separately. The models have the following characteristics
and limits.
Table 14.7.1: Toroparu Model Limits
Direction Minimum (m) Maximum (m) Blocks
Main ZoneEasting 824,200 826,800 260 ColumnsNorthing 713,800 715,700 190 RowsElevation -640 160 160 LevelsSouth East ZoneEasting 826,400 827,500 110 ColumnsNorthing 712,400 713,400 100 RowsElevation -300 140 88 Levels
Source: SRK, 2013
The block size of 10 m square in plan and 5 m vertically was considered appropriate with the
assumed mining selectivity expected for open pit mining in the area. No sub-cells (or part cells) were
used except at the saprolite/fresh rock interface and the primary resolution is to the full block size
which is adequate for the global resource model.
14.8 Search Orientation/ Anisotropy Model
Variograms, indicator variograms and correlograms were constructed for raw and composited assay
values for both Au and Cu; reasonable results were achieved and the variograms are relatively well
behaved. No preferential orientation (anisotropy) of the continuity of mineralization could be
observed but given the distribution of drilling and the geometry of the mineralization this is not un-
expected. Displayed on Figures 14.8.1 and 14.8.3 are ordinary, isotropic and anisotropic variograms
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 151/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 152/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 137
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
To preserve local grade variation, and to fill the volume of the mineralized domains, a search
neighborhood strategy with three search ellipse (SVOL) volumes was used (Table 14.9.2). Only
blocks not estimated with the first set of parameters were estimated with a subsequent expanded
search. In order to preserve this local variation of grades and also have a requirement for gradeassignment using data from more than one drillhole, a minimum of three 1.25 m composites was
required, with a maximum of two from any given hole, for estimation with the first two search
volumes. This results in the constraint that for “Measured & Indicated” confidence at least three 1.25
m composites from at least two drillholes are required for grade assignment.
Table 14.9.2 Search Neighborhood Strategy
SVOLSearch Distance (m) Minimum Number
Of CompositesMaximum From
One DrillholeSearch Or ien tat ion X Y Z
Au1 Dynamic 26 26 13 3 22 Dynamic 52 52 26 3 2
3 Dynamic 156 156 76 2 2Cu1 Dynamic 33 33 16 3 22 Dynamic 66 66 32 3 23 Dynamic 198 198 96 2 2
Source: SRK, 2013
Confidence classifications are initially assigned (latter smoothed as discussed in section 14.10) using
the search volume criteria and constraints of the minimum number of samples and maximum from
one drillhole. This is modified as tabulated below (14.9.3) by the absolute minimum distance to the
nearest composite. A block estimated with the second search volume that is within 10 m of a
composite is categorized as Measured and a block estimated with the third search volume that is
within 15 m of a composite is categorized as Indicated.
Table 14.9.3 Confidence Classification Scheme
Isotropic Absolute DistanceMinimum Number
Of CompositesMaximum From
One DrillholeClass SVOLMinimum Distance to
Nearest Composite
Measured 1 3 2Measured 2 10 m 3 2Indicated 2 3 2Indicated 3 15 m 2 2
Inferred 3 2 2
Source: SRK, 2013
On Figures 14.9.1 and 14.9.2 are plan views and sections that along with the perspective view of
(Figure 14.9.3) of the block model visually demonstrates the effects of the modeled anisotropy in
maintaining the mineralization continuity in preferential orientations.
14.10 Mineral Resource Classification/Confidence Assignment
For many resource models the block-by-block resource classifications should be smoothed into
geologically sensible and coherent zones that reflect a realistic level of geological and grade
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 153/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 138
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
estimation confidence taking into account the amount, distribution, and quality of data. A common
way of implementing this “smoothing” process is to create resource classifications based on block
estimation attributes and the broader geological and data considerations and then to adjust the
classifications of all blocks. This process includes geological rather than purely mathematical input
and is seen as an integral part of the resource classification process. Subsequent to an initial pit
optimization exercise (utilizing all blocks including Inferred) the confidence classification of all blocks
falling within the pit were examined and modifications were made to minimize the existence of
“spots” of, for example, blocks classified mathematically as Inferred that are encompassed by those
classified as Indicated, within areas with reasonable geological continuity and sufficient sampling. On
Figure 14.10.1 are representative plan views of the final modified classification with Measured and
Indicated blocks displayed in green and Inferred in red.
14.11 Resource Statement
The resource model was further investigated with a Whittle™ pit optimization to ensure a reasonable
stripping ratio was applied and a reasonable assumption of potential economic extraction could be
made. Whittle™ software was used to generate pit shells (Figure 14.11.1) for both the Main and SEZones using the operating cost inputs described in the footnote to Table 14.11.2. Incremental cut-
offs for resource reporting were produced with the economic parameters on Table 14.11.1; the
price/cut-off relationship is displayed on Figure 14.11.2.
Table 14.11.1: Resource Report ing Cut-offs
Source: SRK, 2013
Table 14.11.2 summarizes the resource for the Main, SE and both zones at a 0.30 g/t Au cut-off
within the global optimal pit designs. On Tables 14.11.3 and 14.11.4 are summary resources at
various cut-offs for all zones for Measured plus Indicated and Inferred, respectively.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 154/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 139
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 14.11.2: Resource Statement @ 0.30 g/t Au cut -off as o f March 31, 2013
Resource Classi ficat ion Tonnes Au Au oz Cu Cu(All rock types) (000’s) (g/t) (000’s) % (Mlb)
Main ZoneMeasured 41,542 0.98 1,307 0.109 100
Indicated 185,957 0.87 5,203 0.082 334Measured & Indicated 227,500 0.89 6,510 0.087 434Inferred 127,756 0.74 3,045 0.042 118South East ZoneMeasured 2,905 0.97 91 0.037 2Indicated 9,836 0.93 294 0.035 8Measured & Indicated 12,741 0.94 384 0.036 10Inferred 1,768 0.78 45 0.041 2 Al l ZonesMeasured 44,447 0.98 1,398 0.104 102Indicated 195,793 0.87 5,497 0.079 342Measured & Indicated 240,240 0.89 6,894 0.084 444Inferred 129,525 0.74 3,090 0.042 120
Source: SRK, 2013
1. Mineral resources are inclusive of mineral reserves;2. All resources in the revised mineral resource statement are In-Pit resources reported within an optimized pit shellabove an economic cut-off grade of 0.30 g/t Au. The economic cut-off grade was determined using a gold price ofUS$1,350/oz Au, an average metallurgical recovery of 95.9% for gold, Processing + G&A costs of US$11.49/t, andincludes US$112/oz Au for freight, smelting, refining and royalties. Copper metallurgical recovery used was 91%.Pit slopes used in the pit optimization were 45 degrees, and the mining costs used were US$2.06/t for fresh rock.
3. Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is nocertainty that all or any part of the Mineral Resources estimated will be converted into Mineral Reserves;
4. Mineral Resources are reported in accordance with Canadian Securities Administrators (CSA) National Instrument43-101 (NI 43-101) and have been estimated in conformity with generally accepted Canadian Institute of Mining,Metallurgy and Petroleum (CIM) "Estimation of Mineral Resource and Mineral Reserves Best Practices" guidelines;
5. The grades for Au and Cu were estimated separately, and presented as associated average metal grades at the Aucut-off;
6. Mineral resource tonnage and contained metal have been rounded to reflect the accuracy of the estimate, andnumbers may not add due to rounding;
7. The quantity and grade of reported Inferred resources in this estimation are uncertain in nature and there has beeninsufficient exploration to define these Inferred resources as an Indicated or Measured mineral resource and it is
uncertain if further exploration will result in upgrading them to an Indicated or Measured mineral resource category;and
8. The mineral resource estimate for the Project was calculated by Frank Daviess, MAusIMM, R.M. SME, AssociateResource Geologist of SRK Consulting, Inc. in accordance with the Canadian Securities Administrators NationalInstrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) and generally accepted CanadianInstitute of Mining, Metallurgical and Petroleum “Estimation of Mineral Resource and Mineral Reserves BestPractices” guidelines (“CIM Guidelines”).
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 155/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 156/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 141
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
14.12.2 Comparative Statistics
On Tables 14.12.2.1 and 14.12.2.2 are comparative statistics for the grades of model blocks (at a
zero cut-off within the shells) and the composited assay values within the relevant shells.
The average estimated Au and Cu grades of the resource model blocks are marginally lower than
the average grades of the composited values used for the estimation for each of the areas. The
coefficient of variation, already relatively low for the composites, is lower for each of the modeled
areas. In general the model is a “smoothed” representation of the composited data and is adequate
for global resource estimation.
Table 14.12.2.1: Fresh Rock Composi te/Model Statist ics
Population Au g/t Cu %
Model Assay Model AssayBlocks Composites Blocks Composites
Maximum Value 12.90 15.00 0.96 1.10Minimum Value 0.00 0.00 0.00 0.00Mean 0.71 0.76 0.06 0.07
Standard Deviation 0.654 1.235 0.067 0.102Coefficient of Variation 0.92 1.62 1.10 1.47
Source: SRK, 2013
Table 14.12.2.2: Saprolite Compos ite/Model Statisti cs
Population
Au g/t Cu %
Model Assay Model AssayBlocks Compos ites Blocks Compos ites
Maximum Value 5.52 8.00 0.46 0.50Minimum Value 0.00 0.00 0.00 0.00Mean 0.61 0.65 0.06 0.06Standard Deviation 0.537 0.938 0.071 0.080
Coefficient of Variation 0.89 1.43 1.20 1.31
Source: SRK, 2013
For comparative purposes the resource block model was assigned grades using alternative
methodologies to the ordinary kriging scheme (OK) with dynamic anisotropies that is reported above.
These include inverse to the distance squared (ID2) and nearest neighbor (NN). ID2 and OK methods
were used both with the dynamic anisotropy option and with an isotropic (uniform spherical) search
ellipsoid. On Table 14.12.2.3 for Au and Table 14.12.2.4 for Cu, are Measured and Indicated
resources for fresh rock at a zero cut-off estimated with alternative methods. At the zero cut-offs1, for
all cases, the choice of estimators does not have a major impact on the global inventory tonnages or
grade. As expected nearest neighbor (NN) result in the highest estimated grade as there is little
smoothing with this method; differences are minimal. The effects of variable anisotropy are seen as
the increase of grade from 0.542 (Isotropic) to 0.555 (anisotropic); this “preservation of metal” was
the intended outcome of the procedure.
1 Note: a zero cut-off is for comparative purposes only for the entire mineralized datasets, and does not relate to a
resource. Resources cannot be reported at a zero cut-off grade.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 157/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 158/340
Toroparu Gold Project,
Guyana
Figure 14.3.1
Toroparu PlanSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 159/340
Toroparu Gold Project,
Guyana
Figure 14.3.1.1
Toroparu Plan “ Fresh Rock” (grey) “ Saprolite” (orange) DomainsSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 160/340
Toroparu Gold Project,
Guyana
Figure 14.3.1.2
Toroparu Perspective “ Fresh Rock(grey) & “ Saproli te” (orange)
DomainsSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 161/340
Toroparu Gold Project,
Guyana
Figure 14.3.2.1
Toroparu Perspectives “ Fresh Rock(grey) & “ Anisotropy “ (red)Source: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 162/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 163/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 164/340
Toroparu Gold Project,
Guyana
Figure 14.3.3.3
Toroparu Model Cross Sections,Mineralized/non-Mineralized
(green/grey)Source: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 165/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 166/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 167/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 168/340
Toroparu Gold Project,
Guyana
Figure 14.8.1
Variogram, Au (g/t) Modeled Anisotropic & Isotrop ic VariogramSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 169/340
Toroparu Gold Project,
Guyana
Figure 14.8.2
Variogram, Au (g/t) Modeled Anisotrop ic VariogramSource: Company, Year
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 170/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 171/340
Toroparu Gold Project,
Guyana
Figure 14.8.4
Variogram, Cu (%) Modeled Anisot ropic Var iogramSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 172/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 173/340
Toroparu Gold Project,
Guyana
Figure 14.9.1
Resource Model Plans160 Elevation -250 ElevationSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 174/340
Toroparu Gold Project,
Guyana
Figure 14.9.2
Resource Model RepresentativeCross SectionsSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 175/340
Toroparu Gold Project,
Guyana
Figure 14.9.3
Resource Model PerspectiveSource: Company, Year
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 176/340
Toroparu Gold Project,
Guyana
Figure 14.10.1
Resource Model ConfidenceClassif ication -225, -200,
-100 Plan ViewsSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 177/340
Toroparu Gold Project,
Guyana
Figure 14.11.1
Optimized Resource PitsSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 178/340
-
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
$1,070 $1,250 $1,300 $1,350 $1,400 $1,450 $1,500 $1,550 $1,600 $2,030
A u
G / t
Au cut off grade (g/t)
Toroparu Gold Project,
Guyana
Figure 14.11.2
Cut-off/PriceSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 179/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 180/340
Toroparu Gold Project,
Guyana
Figure 14.12.3.2
North-South Swath DiagramSource: SRK, 2013
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
XC 825400 826400
AUKRG
AUNN
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 181/340
Toroparu Gold Project,
Guyana
Figure 14.12.3.3
East-West Swath DiagramSource: SRK, 2013
0
0.5
1
1.5
2
2.5
3
3.5
YC 714890
AUKRG
AUNN
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 182/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 167
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
15 Mineral Reserve Estimate
15.1 Conversion Assumptions, Parameters and Methods
All conversion assumptions such as model dilution, mining recovery, cut-off grade calculation, pitoptimization and costs were taking into consideration to calculate the reserve estimate.
The following steps were used to calculate the reserves:
1. Apply mining dilution to resource block model (using 3D techniques);
2. Gather costs and process recoveries;
3. Input optimization parameters into pit optimizer to calculate nested pits using different gold
selling prices (only Measured and Indicated resources were included as ore);
4. Chose pit optimization shell based on strip ratio, revenue, grade distribution, discounted
cash flow, cash costs, equipment selection sizes, pit footprint, depth of pit, minimum mining
widths, cut-off grade, processing plant size and many other factors;
5. Detailed phase design with ramp access to all benches;
6. Multiple trade off mine plans based on different processing rates (quarterly periods for five
years and yearly until the end of the mine life);
7. Detailed truck haulage estimates;
8. Detailed mine cost estimates based on detailed mine plan;
9. Discounted cash flow based on all capital and operation cost inputs; and
10. Choose final mine plan and cash flow followed by reported reserves.
There follows a description of how reserve dilution was applied and how the in-pit cut-off grade was
calculated.
Model Grade Dilution
The mineralized ore body shell was developed by using two gold cut-offs (0.1 g/t and 0.2 g/t shells).
SRK used the 0.2 g/t shell for grade estimation while the 0.1 g/t shell was used to calculate the
dilution outside of the 0.2 g/t shell. SRK calculated the dilution with the following method:
0.2 g/t Au shell and internal low grade dykes triangulations were used to calculate the
percentage of the block inside of the triangulations;
Because all material within the block model block were within the 0.1 g/t Au shell, SRK
applied a 0.15 g/t Au dilution grade for gold and 0.015% Cu to the volume outside of the 0.2g/t Au shell. This output was then used to calculate on a block by block basis the new 3D
dilution. Blocks that did not touch the 0.2 g/t Au shell or the dykes were not affected; and
This is a purely mathematical manipulation and there was no involvement of lithology or
other geologic criteria. SRK calculation shows a drop of 2% of gold grades and close to 3%
by mass.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 183/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 184/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 185/340
Toroparu Gold Project,
Guyana
Figure 15.1.1
Cut-off Grade Calculation Graph(by different Gold selling price)Source: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 186/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 171
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
16 Mining MethodsMore accurate resource and geologic models produced over the course of 2011/2012 during the
prefeasibility definition drilling campaigns identified two geographically distinct populations of gold
bearing saprolite and fresh rock ores, distinguishable by their copper sulfide contents, ore withrecoverable copper being defined as “Au/Cu Ore”, and without recoverable copper content as “Au
Ore”. The mine plan and production schedule defined in the PFS were optimized for higher
metallurgical recovery by processing these ores separately in different circuits as they are mined
from the Toroparu and SE pits. During the metallurgical testwork program these two ore types were
given the names of ACO (Average Copper Ore) for the “Au/Cu Ore” and LCO (Low Copper Ore for
the “Au Ore”.
The PFS mine plan provides for the excavation of 127.1 Mt of ore (containing 4.107 Moz of gold at
an average grade of 1.00 g/t Au) and 468.9 Mt of waste for a combined total of 596.0 Mt of material
at a life of mine (LoM) stripping ratio of 3.69:1. Mining will be conducted with conventional open pit
mining techniques over a 16-year mine life in two pits, the Toroparu Pit which will be mined in 13
phases, and the nearby South-East Pit (1.2 km to southeast of Toroparu), which will be mined in four
phases. The mine plan includes:
5 Mt of saprolite Au Ore containing 148,000 oz of gold at an average grade of 0.91 g/t Au
that will be processed via conventional cyanide leach;
52 Mt of fresh rock Au/Cu Ore containing 1,953,000 oz of gold with an average grade of
1.17g/t Au and 0.18% Cu that will be processed via flotation concentration; and
70 Mt of fresh rock Au Ore containing 2,006 Moz of gold with an average grade of 0.89 g/t
Au and 0.05% Cu that will also be processed via cyanide leach.
Processing facilities will be developed in three phases:
Pre-production is designed to process 1.18 Mt/y (3,250 t/d) of saprolite Au Ore during that
period;
Phase 1 is designed to process 5.475 Mt/y (15,000 t/d) of fresh rock Au/Cu Ore via flotation
concentration, and a combination of 1,500 t/d of saprolite Au Ore and fresh rock 2,600 t/d of
Au/Cu Ore flotation tailings over the first three years of production; and
Phase 2 is designed to treat 5.745 Mt/y (15,000 t/d) of fresh rock Au Ore, saprolite Au Ore
and Au/Cu Ore flotation tailings via cyanide leach and 2.738 Mt/y (7,500 t/d) of Au/Cu Ore
via flotation concentrate starting in the fourth year of production and continuing for the
balance of the mine life.
Mining operations are planned to commence during the second year of construction of the Project in
the center of the Toroparu pit, with mining of saprolite Au Ore to support pre-production of gold in
saprolite Au Ore processing. The following year mining will be expanded to include mining and
stockpiling of fresh rock ore to support the start-up of fresh rock Au/Cu Ore processing in the first
year of production. Total mining during the two pre-production years is estimated at 15.2 Mt with a
stripping ratio of 1.05:1. From this point, the mine plan calls for 14 years of mining out of a total 16
year production life. The first five years of mining (after pre-production) will continue in the center of
the Toroparu Pit at a rate of 40 Mt/y utilizing small scale mining equipment fleet based on 50 t
capacity haul trucks with a stripping ratio of 3.29:1. Mined fresh rock Au/Cu Ore will be processed in
the concentrate circuit, and fresh rock Au Ore will be stockpiled for later feed into the expanded
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 187/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 172
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
cyanide leach circuit beginning in Year 4 (Phase 2). Loading operations will be accomplished with a
fleet of hydraulic excavators (to enhance ore selectivity) and hydraulic shovel, with operational
flexibility provided by a wheel loader.
In the sixth year of the mine plan the annual mining rate is expected to be ramped up to an average
of 50 Mt/y and the main truck fleet will be switched over to 133 t capacity haul trucks to support theexpanded processing capacity. In Year 13, the annual mining rate will reduce to 21 Mt/y. In Year 14,
open pit operations will be completed for the mineral reserves defined in the PFS mine plan. The
processing plant will continue operating for another two years processing from low grade ore
stockpiles.
16.1 Proposed Mining Method
For the PFS, it is assumed that a conventional open pit operation including drilling and blasting,
loading and hauling.
Drilling and blasting are planned to be performed on 10 m benches in both pits. This matches a
multiple of the block size in the geological block model. Due to the expected selective mining that willbe required for ore mining, loading and hauling are planned to be performed using a half-bench
height for ore, and a full bench heights for waste handling.
The Toroparu pit is planned to be developed first, with the process facility to be constructed adjacent
to this pit. This will minimize the ore haulage requirements during the early years of the Project.
The Project plans to use proven technology, with no requirement for untried or untested technology.
16.2 Geotechnical Mine Design Parameters
Knight Piésold Ltd. (KP) completed a geotechnical site investigation program and pit slope design for
the Toroparu Project. The Project site includes a 30 to 40 m thick sequence of surficial saprolite and
a massive volcanic and metasedimentary rock assemblage. Two major geotechnical domains,
saprolite and Fresh Bedrock, were defined for the pit slope geotechnical assessment.
Five major pit design sectors, namely, Northeast, East, South, Southwest, and Northwest, were
defined for the proposed Toroparu Pit based on the orientations of pit walls and the wall geology.
Sub sectors were also delineated to differentiate the saprolite and Fresh Bedrock domains in each
sector.
It is assumed that moderately sized mining equipment will be used for the Toroparu open pit mining
operations, which allows for a 10 m high single bench to be developed in the pit walls.
The inter-ramp slope angles are typically determined by the bench geometry. A shallow slope angle
of 38 degrees is recommended in the upper saprolite slopes. A steeper inter-ramp slope angle of 53
degrees is recommended for areas with less kinematic controls (South, Southwest, and Northwest
Sectors), while a flatter inter-ramp angle of 50 degrees is appropriate for the East Sector where the
potential for minor planar failure has been identified. The Northeast Sector is limited to an inter-ramp
angle of 45 degrees due to adverse planar structures.
A 16 to 20 m wide catch bench is recommended along the saprolite/Bedrock contact, to intersect
surface run off water and provide additional containment capacity for potential saprolite raveling
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 188/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 189/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 174
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
16.3.4 Optimization Parameters
The pit optimizations have been carried out using Whittle™ optimization software (Whittle™ Version
4.4). Revenue, mining costs, processing values and other factors as described in this section were
input to the Whittle™ software.
Mining Dilution
The block model as imported into Whittle™ was diluted. The optimization process included factors of
0% mining dilution and 100% ore recovery (as this was pre-coded into the block model). These
parameters were supplied by the client but considered by SRK to be reasonable.
Discount Rate
The pit optimization process did not utilize a discounting factor. Inflation was not factored into the
costs, which represent an indication of the “Current Prices” in the analysis.
The Lerchs-Grossmann algorithm (on which the Whittle™ software is based) produces a series of
mathematically optimum pit shells directly linked to the Revenue Factor utilized if the maximum
undiscounted cash flow is the selection criterion for optimization.
Geotechnical Parameters
For the Toroparu optimization, three geotechnical domains were utilized. For the upper Saprolitic
zones, an overall wall angle of 28 degrees was used. Below the saprolite, in the North-East corner of
the proposed pit, an overall wall angle of 38 degree was used. For all other areas of the pit, an
overall wall angle of 45 degrees was used. These parameters are much shallower than the proposed
inter-ramp to account for ramp systems within the pit optimization runs.
For the South-East Pit optimization, two geotechnical zones were utilized. For the upper Saprolitic
zone, an overall wall angle of 28 degrees was used. Below the saprolite, an overall wall angle of 40
degrees was used. The overall wall angle includes any allowances for ramps within each wall.
Royalties
Royalties have been defined by the Sandspring. Royalties to a total of 8% for gold sales and 1.5%
for copper sales have been applied.
Mining Costs
SRK reviewed the proposed costs and modified the input values based on prior experience with
similar projects. SRK has not applied an incremental cost to account for the increased cost of mining
at depth.
Material has been classified either as saprolite or fresh rock, and a unique cost per tonne has been
applied for each material type. For saprolite, the cost per tonne is US$1.54/t and for Fresh (or
Sulfide) Rock, the cost per tonne is US$1.86/t.
Processing Costs and Recoveries
The estimated processing costs for both deposits were supplied by Tt. Three processing methods
have been identified with unique costs for each stream. The processing costs are defined in Table
16.3.4.1.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 190/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 175
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 16.3.4.1: Processing Parameters
Material Type Processing Method Unit Value Recovery
Saprolite (SAP) Carbon in Pulp (CIP) US$/t ROM 7.713 Au – 96.06%
ACO (Au/Cu Ore) Flotation / CIP / Intense Leach US$/t ROM 11.31 Au – 85.46%
Cu – 91%
LCO (Au Ore) CIP / Intense Leach US$/t ROM 10.12 Au – 95.90% Source: SRK
Other Costs
Due to the processing methods, a series of other costs also require inclusion in the optimization.
Table 16.3.4.2 summarizes the optimization parameters used.
Table 16.3.4.2: Optimization Parameters (Base Case)
Parameter Unit Value
Mining Dilution % 0Mining Dilution Grade 0.00
Mining Recovery % 100Toroparu Overall Slope Angle (Above Saprolite / Fresh interface) (
o) 28
Toroparu Overall Slope Angle (Below Saprolite / Fresh interface) (o) 38
Toroparu Overall Slope Angle (Below Saprolite / Fresh interface) (o) 45
South East Overall Slope Angle (Above Saprolite / Fresh interface) (o) 28
South East Overall Slope Angle (Below Saprolite / Fresh interface) (o) 40
Mining Cost (Saprolite Material) US$ / t 1.54Mining Cost (Fresh Material) US$ / t 1.86Mining Rate Mt/y 60Processing Rate (Saprolite) Mt/y 2.0Processing Rate (ACO) Mt/y 15.0Processing Rate (LCO) Mt/y 15.0Process Recovery Au (SAP) % 96.06Process Recovery Au (ACO) % 85.46
Process Recovery Cu (ACO) % 91.00Process Recovery Au (LCO) % 95.90Processing Costs (SAP) US$ / t ore 7.713Processing Costs (ACO) US$ / t ore 11.31 Processing Costs (LCO) US$ / t ore 10.12 General and Administration US$ / t ore 1.37 Sustaining Capital Cost US$ / t ore 0.65Gold (Au) Price US$ / oz 1,400Gold Royalty US$ / oz 112Copper Royalty US$ / lb 0.051Doré Au NSR Deductions / Losses % of Au Sales 0.1Doré Au NSR Transport and Insurance US$ / oz 2.45Doré Au NSR Refining Charges US$ / oz 0.65Cu Concentrate Au NSR Deductions / Losses % of Au Sales 3.0Cu Concentrate Au NSR Smelting and Refining US$ / oz 6.5Cu Concentrate Cu NSR Deductions / Losses % of Cu Sales 4.76Cu Concentrate Cu NSR Treatment and Refining US$/ lb 0.28Freight and Marketing US$ / lb 0.34
Source: SRK
16.3.5 Optimization Process
To optimize both deposits, a series of nested pit shells were calculated over a range of Revenue
Factors (RFs). Each of the nested pit shells were generated based on the maximum undiscounted
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 191/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 192/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 193/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 178
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Geotechnical Parameters
Table 16.4.2 shows the geotechnical parameters used for the Preliminary Economic Assessment
(PEA) pit design. Due to no changes in the geotechnical parameters, SRK applied the same inter-
ramp angles to the new pit design. Table 16.4.3 shows the pit geotechnical parameters for the
saprolite and fresh rock. SRK used the PEA geotechnical parameters and applied smoothingbetween the proposed inter-ramp angles to ensure that smooth sector transitions.
Table 16.4.2: Toroparu Pit Final Geotech Pit Design Parameters Used in Updated PEA
RocktypePit DesignSector
Pit WallOrientation
(º)
KinematicFailure
Mode
BenchFace
Angle (º)
BenchHeight
(m)
BenchWidth
(m)
Inter-ramp
Angle (º)Saprolite - - 65 12 10 38
Fresh Bedrock
Northeast 220 Planar 65 24 13 45East 250 Planar 70 24 11.5 50South 355 Toppling 75 24 11.5 53
Southwest 40 Toppling 75 24 11.5 53Northwest 120 75 24 11.5 53
Source: Knight Piésold*The geotech parameters above does not include the South East pit area. SRK used 45 degrees inter-ramp angles for thesouth-east pit design.
Table 16.4.3: Toroparu and South -East Pits Geotech Pit Design Parameters
Pit RocktypeStart
AzimuthEnd
AzimuthBerm
Width (m)Batter
Angle (º)BenchHeight
DoubleBench
Inter-ramp Angle (º)
Toroparu Fresh
0 5 10.00 70 20 YES 495 10 11.25 70 20 YES 47
10 15 11.75 70 20 YES 4715 20 12.25 70 20 YES 4610 45 12.75 70 20 YES 45
45 48 12.25 70 20 YES 46
45 50 11.75 70 20 YES 4750 55 10.75 70 20 YES 4855 60 10.00 70 20 YES 4960 115 9.50 70 20 YES 50
115 120 9.00 70 20 YES 51120 125 8.50 70 20 YES 52125 130 8.20 70 20 YES 52130 345 7.80 70 20 YES 53
345 350 9.00 70 20 YES 51350 355 9.25 70 20 YES 50355 0 9.75 70 20 YES 50
Toroparu Saprolite 0 0 9.25 70 10 NO 37South-East Fresh 0 0 12.75 70 20 YES 45South-East Saprolite 0 0 9.25 70 10 NO 37
Source: SRK
Figure 16.4.1 shows the Toroparu pit geotechnical sectors used to design the phase designs and
final pit design. Blending sectors were added to ensure smooth transition between 45 to 53 degrees
sectors. Saprolite material was excluded from this methodology.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 194/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 195/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 196/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx
Table 16.6.1.2 shows the planned mill feed schedule.
Table 16.6.1.2: Production Mill Schedule (Mill Feed)
Years
Saproli te Oxide Ore Fresh Au/Cu Ore (ACO) Fresh Au Ore (LCO)
OreProcessed
(kt)
Mill Au Grade
(g/t)
Contained Gold
(koz)
OreProcessed
(kt)
Mill Au Grade
(g/t)
Contained
Gold (koz)
Ore Processed
(kt)
Mill Au Grade
(g/t)
ContainedGold
(koz)
OProcess
Year -2 1,186 1.25 48 0 0.00 0 0 0.00 0 1,1
Year -1 1,186 0.95 36 0 0.00 0 0 0.00 0 1,1
Year 1 548 0.74 13 5,475 1.74 306 0 0.00 0 6,0
Year 2 548 0.61 11 5,475 1.34 236 0 0.00 0 6,0
Year 3 517 0.65 11 5,475 1.24 218 0 0.00 0 5,9
Year 4 64 1.89 4 2,738 0.98 87 5,475 1.32 232 8,2
Year 5 64 1.54 3 2,738 1.63 143 5,475 0.78 138 8,2
Year 6 64 1.85 4 2,738 1.01 89 5,475 0.77 135 8,2
Year 7 64 0.92 2 2,738 1.63 143 5,475 0.77 136 8,2
Year 8 64 1.48 3 2,738 1.73 153 5,475 1.31 231 8,2
Year 9 64 0.76 2 2,738 0.80 70 5,475 0.71 125 8,2
Year 10 64 0.77 2 2,738 1.03 91 5,475 1.13 199 8,2
Year 11 64 0.80 2 2,738 1.32 116 5,475 1.39 244 8,2
Year 12 64 0.76 2 2,738 0.51 45 5,475 0.78 137 8,2Year 13 64 0.48 1 2,738 0.98 86 5,475 0.66 115 8,2
Year 14 64 0.48 1 2,738 0.99 87 5,475 0.89 157 8,2
Year 15 64 0.48 1 2,738 0.49 43 5,475 0.48 85 8,2
Year 16 271 0.48 4 2,505 0.49 40 4,609 0.48 71 7,3
Totals 5,022 0.91 148 51,780 1.17 1,953 70,309 0.89 2,006 127,1
Source: SRK*ACO terminology: Material where the copper content is above 0.09%. – Material subject to Flotation – a.k.a Au/Cu Ore*LCO terminology: Material where the copper content is below 0.09%.– Material subject to Cyanide Leaching – a.k.a Au Ore
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 197/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 198/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 199/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 200/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 201/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 186
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
16.8 Mining Equipment Requirements
16.8.1 Summary
Mining methods will be open pit mining using hydraulic excavators, shovels and wheel loaders loading
haul trucks for waste and ore haulage. The operations are described further in the following sections.Mining activities will include removal of any growth medium (topsoil), free-digging, drilling, blasting,
loading, hauling and mining support activities. Material within the pit will be generally blasted on a 10
high m bench, but it is planned for ore to be mined by excavators in two 5 m flitches (lifts). Saprolite
material (approximately 12% of the total material to be mined) can be loaded directly with hydraulic
excavators without the need for blasting. Waste dumps will be used for material below the cut-off
grade, and stockpile for ore above the cut-off grade. The stripped waste material will be placed in
dumps, either to the north or east of the Toroparu Pit, and lower-grade ore placed in a stockpile, near
to the primary crusher location. Some ore will be sent directly to the primary crusher.
16.8.2 General Parameters and Fleet Selection
Specific requirements dictated the selection of mining equipment types and sizes. Loading equipment
selection focused on generally having diesel-powered hydraulic excavators (backhoes), together with
a front end loader available for added operational flexibility. A hydraulic shovel was also included in a
larger equipment fleet placed into service in Year 6 of full production.
Hydraulic excavators will be primarily used for loading in the open pits (Toroparu and SE pits) and the
front end loader for loading in the low grade stockpile. Trucks will be matched to the loading
equipment units. Additional equipment units were provisioned when required, in keeping with the
planned mine production schedule requirements.
The major mine equipment fleet requirements were based on the annual mine production schedule,
the mine work schedule, and shift production estimates. The mine equipment requirements andcosting were based on the purchase of new equipment. The equipment fleet selection and
requirements are further discussed in the individual sections that follow in this report.
It was planned that all mine mobile equipment would be diesel-powered, in order to avoid the
requirement to provide electrical power into the pit working areas.
The mine operations schedule is proposed to include two twelve-hour shifts per day, seven days per
week for 355 days per year, which includes an annual allowance of 10 days downtime for weather
delays for most of the mine operations, and 15 days downtime for weather delays for the drilling
operations. Mine productivity and costing included estimating the productive operating time per
twelve-hour shift. Non-productive time per shift includes shift change (travel time), equipment
inspections, fueling, and operator breaks. It was estimated that the total time per shift for these itemswill be 1.68 hours. The scheduled production time (scheduled operating hours) was therefore
estimated at 10.32 hours per shift, representing a (shift) utilization of 86% of the twelve-hour shift
period (and excludes mechanical availability and work efficiency factors).
In addition, allowances were made for work efficiencies including equipment moves (production
delays while moving to other mining areas within the pit), and certain dynamic operational
inefficiencies. These work efficiencies are further discussed in the respective sections for drilling,
loading and hauling.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 202/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 187
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Equipment fleet mechanical availability was estimated for the various major mine equipment fleets,
including drills, hydraulic excavators, hydraulic shovels, front end loaders, trucks, etc. (with
replacement equipment units assumed to be new). For the large haul truck fleet annual adjustments
were made depending on the age (in terms of operating hours) of the equipment as averaged over the
entire fleet. Table 16.8.2.1 shows the estimated mechanical availabilities used, and the planned
equipment life for each equipment type.
Table 16.8.2.1: Mechanical Availabil ities and Planned Equipment Life
Op Hr Intervals0 -
5,0005,000 -10,000
10,000 -15,000
15,000 - 30,000 - Over Unit
30,000 50,000 50,000 Life
Mech. Mech. Mech. Mech. Mech. Mech. Oper
Major Mining Equipment Avail. Avail. Avail. Avail. Avail. Avail. Hrs
Type (%) (%) (%) (%) (%) (%) (op hrs )
Blasthole drill - AC PV-235 75 75 75 75 75 - 50,000Control blasthole drill – AC D65 75 75 75 75 75 - 50,000Front end loader - Cat 88H 80 80 80 80 80 - 50,000Front end loader - Cat 993K 80 80 80 80 80 80 60,000Hydraulic excavator - Cat 390 85 85 85 85 85 - 40,000Hydraulic excavator - Cat 6018 85 85 85 85 85 85 80,000Hydraulic excavator - Cat 6040 85 85 85 85 85 85 90,000Hydraulic shovel - Cat 6040 85 85 85 85 85 85 90,000Haul truck - Cat 740B 85 85 85 85 85 - 50,000Haul truck - Scania 10x4 85 85 85 85 - - 18,000Haul truck - Cat 785D 92 90 88 84 80 75 75,000Track dozer - Cat D9T 75 75 75 75 75 75 60,000Wheel dozer - Cat 844H 75 75 75 75 75 75 60,000Motor grader - Cat 16M 75 75 75 75 75 - 50,000Water truck - Scania 8x4 30kL 75 75 75 75 - - 20,000Excavator - Cat 374DL 75 75 75 75 - - 30,000Compactor - Cat CS/CP-54 75 75 75 75 - - 30,000
Source: SRK
Table 16.8.2.2 shows the mining equipment requirements for selected years of the mine plan.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 203/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 188
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 16.8.2.2: Planned Mining Equipment Requirements for Selected Years
Equipment Units Used Make Model Size -2 -1 1 2 4 6 8 10 12 14
Drilling
Blasthole drill - new Atlas Copco PV-235-D 165 mm 0.6 2.8 3.0 3.2 3.2 4.3 3.9 4.3 0.7
Control blasting drill Atlas Copco SROC D65 110 mm 1 1 1 1 1 1 1 1 1
LoadingFront end loader Caterpillar 988H 6.4 m3 1.4 0.6 1.3 1.8 2.1 1.8 0.6 1.1 1.4 1.2
Front end loader Caterpillar 993K 12.2 m3 0.7 0.6 0.9 0.1
Hydraulic excavator Caterpillar 390DL 5.0 m3 1.7 2.6 7.7 7.5 7.2 6.9 3.4
Hydraulic exc/shovel Caterpillar 6018EX/FS 10.0 m3 0.9 2.9 2.9 2.9 3.0 2.9 2.0 2.8
Hydraulic exc/shovel Caterpillar 6040EX/FS 22.0 m3 0.8 2.0 1.9 1.9 0.6
Hauling
Haul truck - new Caterpillar 740B 40 t 0.2 3.7 3.7 3.7 3.6 3.2 2.4 1.4 2.0 1.3
Haul truck - new Scania G460CB 10X4 50 t 3.6 8.5 42.1 47.6 57.9 57.5 36.3 19.9 19.8
Haul truck - new Caterpillar 785D 133 t 6.8 24.5 24.8 24.7 12.2
Other Mine Equipment
Crush/Screen Plant Manufacturer Jaw/Cone 335 kW 1 1 1 1 1 1 1 1 1 1
Track dozer - new Caterpillar D9T 306 kW 3 4 4 4 4 5 5 5 5 3
Wheel dozer - new Caterpillar 844H 468 kW 0 2 2 2 2 3 3 3 3 2
Motor grader - new Caterpillar 16M 221 kW 2 3 3 3 3 3 3 3 3 3
Backhoe loader Caterpillar 450E 102 kW 1 1 1 1 1 1 1 1 1 1
Water truck - new Scania P410CB 8X4 30,000L 1 2 2 2 2 2 2 2 2 2
Excavator - new Caterpillar 374DL 355 kW 1 2 2 2 2 3 3 3 3 2
Compactor - new Caterpillar CS/CP 54 97 kW 2 2 2 2 2 2 2 2 2 2
Support Equipment
Transport/mover Manufacturer Model 360 t 1 1 1 1 1 1 1 1 1 1
Truck crane Manufacturer Model 120 t crane 1 1 1 1 1 1 1 1 1 1
Recovery truck Scania G460CB 8X8 360 kW 1 1 1 1 1 1 1 1 1 1
Secondary blast drill Manufacturer 75 kW 64 mm 1 1 1 1 1 1 1 1 1 1
Fuel/lube truck Scania P410CB 8X4 30,000 L 1 1 1 1 1 2 2 2 2 1
HD mechanic's truck Scania P360CB 6X4 1 1 2 2 2 2 2 2 2 2
Flatbed truck Scania P360CB 6X4 19 t crane 1 1 1 1 1 1 1 1 1 1
Welding truck Manufacturer Model 1 1 1 1 1 1 1 1 1 1Tire service truck Scania P360CB 6X4 1 1 1 1 1 1 1 1 1 1
Forklift Manufacturer Model 1 1 1 1 1 1 1 1 1 1
Pit pumps/generators Flygt/Gen BS2290-434 82 kW 4 4 4 4 8 8 8 8 8 4
Pit pumps & engines Godwin/Cat HL260M/C18 430 kW 2 2 3 6 6 7 7 8 5
Personnel van/bus Manufacturer Model 5 5 5 5 5 5 5 5 5 5
Service pickup Manufacturer 4x4 5 15 15 15 15 15 15 15 15 15
Light plant Manufacturer Portable 8 kW 10 10 10 20 20 20 20 20 20 20
Blasting
Blasting flatbed truck Scania G360CB 4X4 1 1 1 1 1 1 1 1 1
ANFO/Emulsion truck Scania P360CB 6X4 13 t 1 1 1 1 1 1 1 1 1
Blasters crew truck Manufacturer 4x4 1 1 1 1 1 1 1 1 1
Blasthole stem truck Scania P360CB 6X4 1 1 1 1 1 1 1 1 1
Source: SRK
16.8.3 Dril ling
The planned drilling equipment fleet will consist of Atlas Copco PV-235 units. This fleet was based on
drilling 165 mm blastholes to an average depth of 11.5 m (including a 1.5 m sub-drill) for development
of 10 m high benches. The drills can single-pass drill (no rod changes) such holes.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 204/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 189
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The planned nominal production blasthole pattern is equivalent to a 5.9 m x 5.9 m pattern (spacing
and burden) in waste and ore, however, in practice the burden and spacing will vary. (The planned
nominal 5.9 m square pattern would be approximately equivalent to a 5 m x 7 m pattern.) For the main
production drilling an instantaneous drilling rate of 0.65 m/minute was estimated for waste and ore.
Allowances were made in the drilling productivity estimates for re-drills (5%) and moving to new
working areas. Fleet requirements were based on drilling all of the fresh rock within the planned openpits (88% of material).
Allowance was also made to have a dedicated drill (for drilling wall control blasting blastholes and
other specialized drilling situations. Table 16.8.3.1 shows selected drilling statistics based on the
planned drilling equipment and drilling patterns for waste and ore.
Table 16.8.3.1: Drilling Statistics Per Unit
Item Unit Value
Rock Type Waste & OreWaste/Ore Pattern Size m x m 5.9 x 5.9Drilling Tram and Set Up Time min/op hr 8.3Drilling Penetration Rate m/min 0.65
Drilling Time per Blasthole min 17.7Moving and Delay Time min/op hr 10Production per Unit (100% Available) * t/op hr 2,144
Source: SRK*Includes allowance of 5% for re-drills.
Table 16.8.3.2 shows selected drilling productivity information based on the planned drilling
equipment. Annual production capacity for per drill is 11.6 Mt/y.
Table 16.8.3.2: Drilling Product ivit y Per Unit
Item Unit Value
Rock Type Waste & OreProduction per Unit (100% Available) t/op hr 2,144Planned Operating Hours per Shift scheduled op hrs 10.32Planned Operating Hrs per Year* scheduled op hrs 7,224Estimated Mechanical Availability** % 75%
Actual Operating Hours per Year op hrs 5,418 Annual Production Capacity per Unit Mt/y 11.6
Source: SRK*Includes allowance of 15 days downtime for weather delays.**Typical mechanical availabilities for drills used.
16.8.4 Blasting
Bulk emulsion explosives will be used for blastholes. Blasting requirements were based on blasting allfresh rock within the planned open pits (88% of material).
The powder factor for production blasting was estimated to be 0.233 kg/t (kg explosives per tonne of
rock), based on an estimate by Orica Mining Services. As previously mentioned, a 5% contingency
allowance was made for additional blasthole drilling (closer drilling to achieve proper fragmentation),
and this contingency also includes the necessary explosives.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 205/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 190
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The explosives provider for the mine will have a dedicated bulk emulsion plant, which will be capable
of sufficient production for the planned mining operations. Blasting accessories will be transported to
site and stored in suitable explosives magazines.
The mine will have a 13 t emulsion truck, which will deliver bulk explosives to the blast sites during
daylight hours. The blasting equipment fleet will include a dedicated stemming truck, a flatbed truck
and blasting crew truck. Stemming material will be mainly drill cuttings. The mine blasting crew will
manage and conduct the blasting operations.
16.8.5 Loading
Loading equipment selection included having a combination of diesel-powered hydraulic excavators,
hydraulic shovels, and front end loaders for operational flexibility. The hydraulic excavators are
capable of mining more selectively, and will be used for mining most of the ore, and part of the waste.
The hydraulic shovels will be primarily used for loading waste. The front end loaders (6.4 m 3
Caterpillar 988H class) will be used for stockpile re-handling loading duties.
The loading equipment fleet for the earlier years of the mining operations was planned to be a
combination of equipment consisting of up to eight smaller hydraulic excavators (5.0 m 3 Caterpillar
390 DL class, Excav1), up to two medium size hydraulic excavators (10.0 m3 Caterpillar 6018 class,
Excav2), one medium size hydraulic shovel (10.0 m3 Caterpillar 6018 class), and two front end
loaders (6.4 m3 Caterpillar 988H class wheel loaders, FEL1). This equipment will load a fleet of 50 t
capacity haul trucks (Scania G460CB 10x4 class units). A fleet of four 40 t capacity articulated dump
trucks (ADTs) was planned, which can be placed in service for either partial mining of saprolite
material within the pit, or re-handling main stockpile ore to the primary crusher.
Mid-way through the mine life, the smaller hydraulic excavators will be phased out, and large loading
equipment units will be brought into operation. These large units will be one hydraulic excavator (22.0
m3 Caterpillar 6040 class, Excav3), one hydraulic shovel (22.0 m3 Caterpillar 6040 class), and one
large front end loader (12.2 m3 Caterpillar 993K class, FEL2). These units will load a fleet of 133 tcapacity haul trucks (Caterpillar 785D class units).
The medium size hydraulic excavators and shovel (10.0 m3 Caterpillar 6018 class units) will be
capable of loading both the 50 t and 133 t capacity haul trucks.
The hydraulic excavators and shovels were estimated to be able to free-dig approximately 12% of the
total material within the planned open pit (saprolite waste and ore). Dry density for saprolite was
estimated to be 1.84 t/ m3 and for fresh rock 2.76 t/ m
3. Saprolite moisture content was estimated to
be 20% on average (varying with season and depth), and swell in loading to be 20%. Fresh rock
moisture content was estimated to be 6% on average, and swell in loading to be 40%.
Table 16.8.5.1 shows selected loading statistics for the planned loading units in saprolite.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 206/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 207/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 208/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 209/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 210/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 211/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 212/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 213/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 214/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 215/340
Toroparu Gold Project,
Guyana
Figure 16.5.1
Toroparu Pit Phase DesignSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 216/340
Toroparu Gold Project,
Guyana
Figure 16.5.2
South-East Pit Phase DesignSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 217/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 218/340
Toroparu Gold Project,
Guyana
Figure 16.5.4
South-East Final Pit Design -Measured and Indicated BlocksSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 219/340
Toroparu Gold Project,
Guyana
Figure 16.5.5
Mine Plan Progress MapsYear 5 EndSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 220/340
Toroparu Gold Project,
Guyana
Figure 16.5.6
Mine Plan Progress MapsYear 10 EndSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 221/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 222/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 208
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
17 Recovery Methods
17.1 Summary
The Toroparu processing facility will be developed in three phases over the life of mine (LoM). This is
to accommodate for variation in ore types over the production schedule. .
The first period is characterized as the Pre-production Phase. This phase is estimated to consist of
two years, during which the facility will process 3,250 t/d of saprolite through a carbon-in-pulp (CIP)
leach circuit using a refurbished ball mill already in the possession of Sandspring. The CIP circuit and
downstream process equipment will be designed to expand to the full production rate for processing a
combination of flotation tailings and saprolite during Phase 1.
Phase 1 consists of processing 15,000 t/d of Gold Ore with Average Copper (ACO) via copper
flotation of gravity tailings with cyanide leaching of the cleaner scavenger flotation tailings via a CIP
circuit alongside saprolite. It is estimated that this will occur for the first five years of the mine life.
Phase 2 consists of processing 15,000 t/d of Gold Ore with Low Copper (LCO) via CIP leaching and7,500 t/d of ACO via flotation with CIP leaching of the cleaner scavenger tailing. This phase continues
over the remaining LoM.
17.2 Overview
The estimated mineral reserves included in the mine plan as developed by SRK total approximately
51.8 Mt of ACO grading 1.17 g/t Au, and 18% Cu; 70.3 Mt of LCO grading .89 g/t Au, and 5.0 Mt of
saprolite grading .91 g/t Au. The final process plant will be designed to treat 8.2 Mt/y of ore at a
throughput rate of 22,500 t/d dry solids at peak production during Phase 2. Instantaneous milling
throughput is dependent on ore hardness as well as which phase of production the facility is operating
under. The operating basis is 365 days available per year with continuous two shifts per day and
twelve-hour shifts. The annual operating hours for design for continuous process and water treatment
areas is 8,322 hours.
A simplified schematic drawing of the proposed facility is provided in Figure 1.7.1. Note that this figure
effectively combines both Phase 1 and Phase 2 into one diagram, thus not all equipment shown will
run simultaneously, but all equipment shown will operate at least in one phase.
17.3 Design Basis
17.3.1 Preproduction-Phase
During preproduction only saprolite ore will be processed. The design basis for the principal process
areas during the pre-production phase is summarized as follows:
A front-end loader will deposit RoM saprolite into a hopper. This hopper will discharge to a screen that
separates and sends oversized saprolite to a stockpile for future processing in later years. Screened
undersize reports to a refurbished ball mill already in the possession of Sandspring. The ball mill
grinds the ore to P80 200 μm, and operates in closed circuit with a cyclone. The cyclone overflow
reports to a CIP circuit. The CIP circuit is designed for a throughput of 3,250 t/d of saprolite ore. This
equipment will be utilized in the Phase 1 expansion.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 223/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 209
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Desorption and gold room areas are designed to recover the maximum gold, calculated nominally by
month over LoM. Carbon regeneration area is designed to reactivate five tons of carbon per day.
Detox area will be designed to treat 3,250 t/d of CIP circuit saprolite tailings at a feed density of 30%
solids and will achieve a final CNWAD concentration of 0.5 ppm. This target remains constant over
the LoM for all phases regardless of feed material
17.3.2 Phase 1: 15,000 t/d ACO and Saprolite
Phase 1 is designed to receive and process ACO in a two stage crushing circuit feeding into an HPGR
circuit. The saprolite ore runs in parallel to the ACO process maintaining the preproduction flow circuit
as described previously.
The crushing circuit will receive 15,000 t/d of ACO, which undergoes two stage crushing. Stage 1
consists of a jaw crusher. Stage 2 is comprised of a screen and cone crusher operating in open
circuit. The product of Stage 2 reports to the ACO flotation feed stockpile. Material from this stockpile
is reclaimed and fed to an HPGR operating in closed circuit with edge recycle being recirculated via
conveyors. The HPGR product undersize reports to a ball mill feed conveyor.
The ball mill circuit will grind ACO material at a throughput of 15,000 t/d and achieve a product size of
P80 150 μm. The ball mill circuit is equipped with a gravity concentrator to enhance gold recovery, the
concentrate of which undergoes intense cyanide leaching and recovery through electrowinning.
The ball mill cyclone overflow reports to two parallel trains of rougher flotation, the concentrate of
which reports to the regrind and cleaner flotation circuit. The rougher flotation tailings report to a
dedicated tailings thickener.
The regrind circuit consists of a single tower mill operating in closed circuit with a cyclone cluster, the
overflow of which reports to cleaner flotation. The cleaner flotation circuit consists of two parallel trains
of float cells. The concentrate from each bank of 2nd cleaner floatation cells is discharged to a
common concentrate thickener. Concentrate is dewatered via thickening and filtration to produce afinal product. The tailings from the 1st cleaner scavenger float cells are sent to the CIP circuit for gold
recovery via cyanide leach.
The CIP circuit consists is expanded to a single train of five tanks that receives both the saprolite and
ACO cleaner scavenger flotation tailings. Carbon is recovered from the CIP tanks and is sent to the
desorption circuit where it undergoes and acid wash and elution with a barren solution. The resulting
pregnant solution is processed through an electrowinning circuit to produce a gold sludge. The sludge
is then further refined to produce gold doré via a furnace. The barren CIP tailings report to tailings
thickener for dewatering prior to detoxification via the air/SO2 method.
17.3.3 Phase 2: 15,000 t/d LCO with 7,500 t/d ACOPhase 2 is designed to receive and process LCO and ACO and minor amounts of saprolite until the
end of the mine life. The crushing circuit is carried forward from Phase 1 and operated for a longer
period to accommodate the extra tonnage throughput. Crushing area will receive 15,000 t/d of LCO
and 7,500 t/d of ACO material, which are processed independent of each other in separate crushing
circuits. The product from the Stage 2 crusher reports to either the ACO flotation feed stockpile or the
LCO leach stockpile. Material from each stockpile is reclaimed and fed to an HPGR operating in
closed circuit with a screen. The LCO and ACO material have separate dedicated HPGR units. The
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 224/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 210
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
LCO material is sent to the previous Phase 1 HPGR unit; A new HPGR unit is needed to process the
ACO material. The configuration of each circuit follows as previously described for Phase 1 with each
of the screen undersize materials reporting to their respective ball mill feed conveyor.
The grinding area for each feed material is comprised of a ball mill operating in closed circuit with a
cyclone cluster. The Phase 1 ball mill is dedicated to processing LCO material and a new ball mill is
required to process the ACO material. The grinding mills will grind both materials to P80 150 μm.
Each grinding train also includes a gravity concentrator which receives a feed from the cyclone
underflow. The gravity concentrate reports to intense cyanide leaching as a batch process for gold
recovery. The leach solution from both circuits is subsequently pumped to the gold room
electrowinning area. Each ball mill will be sized for 15 k and 7.5 k.
The flotation circuit is the same circuit as in Phase 1, however only one train of float cells is used as
the throughput has been reduced to half. The regrind mill remains the same but will operate at a
reduced load.
The CIP area is expanded into two trains of five CIP tanks each, now receiving feed as fresh LCO
material and a reduced amount of ACO cleaner scavenger flotation tailings. Each train shares a single
loaded carbon recovery and a single barren carbon dewatering screen.
Tailings from the CIP process are sent to a designated tailings thickener. From here, they are
thickened to 45% solids prior to detox. Additionally, the thickener serves as a wash system to reduce
the CNWAD concentration prior to detoxification. Rougher flotation tailings report to a separate tailings
thickener, the underflow of which can bypass cyanide detoxification.
Desorption and gold room circuits are the same as in Phase 1
Detox area will treat 16,250 t/d of thickened adsorption circuit tailings using the air/SO2 method.
17.4 Mass and Water Balance
A detailed mass and water balance covering all streams within the process plant has been prepared
by Tt based on daily throughput requirements, plant availability, and the design feed grades for gold
and copper.
17.5 Process Design Criteria
17.5.1 Primary/Secondary Crushing and Stockpile
ROM material is deposited into a feed bin, which is discharged via an apron feeder to a grizzly at a
design throughput of 1,340 t/h.
Table 17.5.1.1: Primary Jaw Crusher
Crusher duty, h/d 16.8Crusher daily throughput, t/d (average) 22,500Crusher hourly throughput, t/h (design) 1,340Crusher availability, % 70Crusher type Jaw
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 225/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 226/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 212
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 17.5.2.3: HPGR Phase 2
Number of HPGR’s 1Design Capacity, t/h 510 Roll width, m 1.2 Roll diameter, m 1.7 M-dot, ts/hm 200
Motor power, kW 895
Table 17.5.2.4 Ball Mill, Phase 2
Number of mills 1Mill size, m 5.5 x 7.9 EGL Mill power, kW 2,983 Ball mill product size, P80, µm 150 Classification type Hydrocyclone Recirculating load, % (nominal) 200 Cyclone diameter, mm 660 Number of cyclones 8 operating/4 standby
17.5.3 Gravity Circui t and Intense Cyanide Leaching
A gravity concentrator is placed on a split stream of each grinding train’s cyclone underflow stream.
The gravity tails reports back to the ball mill, while the concentrate is intermittently collected and
undergoes batch intense cyanide leaching. The leach solution is pumped directly to the pregnant
eluate tank in the electrowinning area.
17.5.4 Rougher Flotation Circui t
The rougher flotation circuit consists of two parallel trains of seven 100 m3 rougher flotation cells
operating at a feed density of 30% solids to achieve a plant retention time of 50 minutes. During
Phase 2, this is reduced to a single train of seven float cells. The concentrate from both trains ofrougher flotation are discharged to a common regrind cyclone feed pumpbox.
Table 17.5.4.1: Rougher Flotation Circu it
No. of parallel trains 2No. of float cells per train 7 Volume per float cell, m 100Plant retention time per train, min 50
17.5.5 Regrind Circui t
The regrind circuit consists of a single VTM1500 tower mill operating in closed circuit with a regrind
cyclone. The regrind cyclone feed box receives input from the tower mill discharge as well as rougher
flotation concentrate and products from the cleaner flotation circuit. The equipment associated with
the regrind circuit remains constant between Phase 1 and Phase 2. The grinding circuit has an
assumed recirculating load of 200% of the rougher concentrate.
17.5.6 Cleaner Flotation Circui t
The cleaner flotation circuit consists of two parallel trains of 1st cleaner, 2nd cleaner, and 1st cleaner
scavenger float cells. Each cleaner flotation train is sized to handle 71 t/h of feed solids with a feed
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 227/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 213
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
density of 25% solids. The 1st cleaner concentrate reports to 2nd cleaner flotation, while the tailings
report to 1st cleaner scavenger flotation. The scavenger concentrate and 2nd cleaner tailings report to
a pumpbox, which in turn discharges to the regrind cyclone feed pumpbox for recirculation. The 2nd
cleaner concentrate advances to the concentrate dewatering circuit. During Phase 2, only a single
train of cleaner flotation cells is operational due to the decreased availability of ACO material.
A summary of the cleaner flotation circuit criteria is presented below.
Table 17.5.6.1: 1st Cleaner Flotation Circuit
No. of parallel trains 2No. of float cells per train 5Volume per float cell, m 20Plant retention time per train, min 20
Table 17.5.6.2: 1st Cleaner Scavenger Flotation Circuit
No. of parallel trains 2No. of float cells per train 4
Volume per float cell, m 20Plant retention time per train, min 9
Table 17.5.6.3: 2nd Cleaner Flotation Circuit
No. of parallel trains 2No. of float cells per train 3Volume per float cell, m 10Plant retention time per train, min 7
17.5.7 Concentrate Dewatering Circui t
The concentrate dewatering circuit consists of a 11.0 m diameter concentrate thickener with
downstream pressure filters. The concentrate from 2nd cleaner flotation reports to the concentrate
thickener, where it is thickened to an underflow density of 60% solids. The moisture content is
subsequently reduced further to 92% solids in the pressure filters, which discharge into a concentrate
stockpile. Reclaimed water is recycled into the process.
The concentrate thickener and filter presses are sized to handle the anticipated Phase 1 demand of
approximately 8 t/h. During Phase 2, the same thickener is used with the option to operate with a
single filter press.
17.5.8 CIP Circuit
The CIP leach circuit for Preproduction and Phase 1 consists of one train of five tanks, two of which
serve as CIP stages. The solids feed rate is approximately 147 t/h and 176 t/h at continuous operation
for Preproduction and Phase 1, respectively. During Phase 2, the circuit is expanded to two parallel
trains, five tanks per train, of CIP receiving a combined feed of 713 t/h from both LCO feed and ACO
cleaner scavenger tails.
A summary of the CIP circuit criteria is presented below.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 228/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 229/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 215
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
17.5.10 Electrowinning and Gold Room
Gold is recovered from pregnant eluate by electrowinning in a single train of three electrowinning
cells. Gold sludge is collected onto woven wire stainless steel mesh cathodes. The gold sludge is
recovered from the cathodes and further refined in a furnace to produce a gold doré. Despite the
absence of Hg in the deposit, a wet scrubber is included in the design to mitigate any potential
discharge into the atmosphere.
Table 17.5.10.1: Electrowinning
Number of electrowinning cells 3Cell Type SludgingNumber of Cells Operating 3Cell Arrangement Series
Table 17.5.10.2: Smel ting
Method Gas FiredHours per Smelt 4
Pours per Week 2Strips per Smelt 3-4Slimes Treatment Method Dry & Direct SmeltMaximum Bar Size 800 oz
17.5.11 Carbon Regeneration
Stripped carbon is treated in a rotary kiln operating at nominally 700° C to remove adsorbed organics
and restore carbon activity. The regeneration capability is designed to treat five tons of stripped
carbon in a 24 hour period.
A summary of the carbon regeneration criteria is presented below.
Table 17.5.11.1: Kiln Carbon Dewatering Screen
Screen type VibratingScreen deck material PolyurethaneScreen aperture, mm 0.8Screen feed rate, m /h 3.1Screen drainage rate, m /h/m 25
Table 17.5.11.2: Barren Carbon Dewatering Screen
Screen type VibratingScreen deck material PolyurethaneScreen aperture, mm 0.8
Screen drainage rate, m /h/m 25
17.5.12 CIP Tails Detoxification and Tails Dewatering
The CIP tailings report to a tailings thickener where they are thickened to approximately 38% solids in
Phase 1 and 45% in Phase 2. In addition to thickening, the underflow is washed such that the cyanide
content has been reduced prior to detoxification. The washed thickener underflow is subsequently
treated in an air/SO2 detox reactor to reduce CNWAD levels to below 0.5 ppm. The rougher flotation
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 230/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 216
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
tailings are treated in a separate dedicated tailings thickener such that the underflow can bypass the
detoxification circuit.
17.5.13 Reagents
The major reagents to be used in the process plant will be:
Lime (quicklime);
Sodium Cyanide;
Sodium Hydroxide;
Nitric Acid;
Flocculant;
Copper Sulfate;
Sodium Metabisulfite;
A3148A Flotation Collector; and
MIBC Flotation Frother.
The reagent facilities are described as follows.
Quicklime (Lime)
A wet slaking system in which lime pebbles will be fed to a tower mill in closed circuit with a cyclone.
The cyclone overflow product reports to a surge tank, from which lime slurry is pumped throughout the
process as needed. The demand for lime varies between LoM phases.
Sodium Cyanide
Sodium cyanide will be delivered in Isotainers in solid form. Dissolution and unloading will be carried
out simultaneously by pumping diluted solution from the mixing tank through the Isotainer and back to
the mixing tank. Cyanide will be added to the CIP and Elution Circuits via metering pumps. The
demand for cyanide varies over the LoM with each phase of production.
Sodium Hydroxide
Sodium hydroxide (caustic soda) will be delivered to the site in solid form in bulk bags and mixed in
the caustic soda mixing tank. The caustic soda solution will be pumped to the desorption and
electrowinning circuits.
Copper Sulfate
Copper sulfate will be delivered as needed for makeup and mixed in the copper sulfate mixing tank.
The mixed solution reports into the storage tank, from which it is pumped directly to the cyanide
detoxification circuit. The demand for copper sulfate varies each phase over the LoM, particularly due
to changes in copper in the RoM material.
Sodium Metabisulfite
Sodium metabisulfite (SMBS) will be delivered in bulk bags and mixed in the SMBS mixing tank and
subsequently transferred to the SMBS storage tank. This solution is pumped directly to the cyanide
detoxification circuit. The demand for SMBS varies dependent on the ore type processed.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 231/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 217
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
A31418A Flotation Col lector
A31418A flotation collector will be delivered as a solution in a bulk container. This container is
offloaded into a holding tank, from which it is pumped directly to the flotation circuit.
MIBC
MIBC will be delivered as a solution in a bulk container. This container is offloaded into a holding tank,
from which it is pumped directly to the flotation circuit.
Flocculant
Flocculant will be delivered in bulk bags and mixed in the flocculant mixing tank, from which it is
pumped to the mixed flocculant holding tank for distribution to the thickeners throughout the process
facility.
Other Reagents
Other reagents and consumables used are:
Activated carbon for the CIP circuit; Borax, nitre and silica for gold room fluxes;
Diesel fuel for the elution heaters and regeneration kilns; and
Grinding media for ball mills and the tower mill.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 232/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 233/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 234/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 235/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 221
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Truck Fuel Facility and Equipment Ready Line
The vehicle fueling facility and ready line will be located at the entrance to the plant area adjacent to
the main haul road access to the mine pits. The fueling facility will store about 800,000 L of diesel for
the initial years and will be doubled (1,600,000 L) when the operation begins using the CAT 785D
trucks. Smaller tanks will hold a variety of oils, service fluids and lubricants. The ready line will be
located adjacent to the fueling facility and will be well lighted for 24- hour use.
Explosives Storage
An explosives storage pad is provided for supplier’s explosives magazine. An area of approximately
100 m x 100 m has been identified on high ground approximately 400 m north of the entrance station.
The explosives storage area is at an approximate elevation of 128 m. It is accessed by the main
access road to an area near the Puruni Bridge. The explosives storage area is isolated from the mine
support, plant and man camp facilities, but is in close proximity to the main and satellite pit operations.
18.1.5 Process Support Facilit ies
The process plant will be located on high ground, at an approximate elevation of 106 m, adjacent tothe run-of-mine stockpile and low grade ore stockpile. Adjacent to the plant will be the process
operations support facilities that include:
Administration Building;
Laboratory;
Workshop, warehouse and storage yard; and
Entry station.
Administrat ion Bui ld ing and First Aid Faci li ty
The administration building will be located in the plant area and south of the process facilities. The
building is sized as a 25 m x 18 m, single-story, pre-engineered, steel-framed structure with walls and
roof to be erected upon a spread footing foundation. The building will provide offices for the process
operations staff, conference/training facilities, toilets, break room, and safety.
Adjacent is a dedicated first aid facility (10 m x 5 m) for early care treatment.
Laboratory
The laboratory building will be approximately 50 m x 30 m, single-story, pre-engineered, steel-framed
structure with walls and roof to be erected upon a spread footing foundation. It will be located adjacent
to the main process facilities on the south side. The laboratory will house sample preparation,
assaying, testing facilities along with supporting sample and chemical storage rooms.
Warehouse, Workshop and Storage Yard A separate building is planned for process operations workshop/warehousing activities. The
warehouse/workshop will have about 1,800 m2 of covered floor space. This work shop is set-up to
perform major repair service to the process equipment. For equipment were the shop cannot
accommodate, repairs will be outsourced. Adjacent to the building will be a fenced compound that will
store bulk items and equipment as necessary.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 236/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 222
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Gatehouse and Weigh-Scale
An entry area including a guard house and weigh-scale will be located at the main entrance to the
property just south of the mine for traffic and inventory control. The entry area is graded above the
Puruni River floodplain at elevation 98 m. The entry area is approximately 100 m x 50 m to allow room
for a lay down, parking, and turn-around.
18.1.6 Man Camp
The man camp will be located approximately 700 m east of the plant area. The camp is defined by a
rectangular pad approximately 400 m x 200 m at elevation 105 m. The pad slopes down to the east at
2%. The camp facility is up-wind and up-gradient from the plant facility, and is shielded from the plant
area by a broad ridge with a maximum elevation of approximately 123 m.
A dormitory style man camp facility is proposed for the Project. The facility includes 490 single person
rooms with shared bath facilities, two 24 unit single dorms with private bath facilities, a recreation
complex, a commercial laundry facility, a medical unit, an office unit that includes a greeting area and
four offices, and a kitchen and dining unit.
18.1.7 Additional Suppor t Facilities
Airstr ip
The Toroparu site includes an existing airstrip which will remain in service for the life of the Project.
The existing airstrip location will interfere with the main pit ultimate boundary, later in the mine life. To
alleviate this interference, it will be extended approximately 200 m toward the southeast.
Communications
Radio Communications Opportunities and Risks
A radio base station will be provided for plant wide site-to-office communications within a 10km radius
from the communications center for use in the following areas:
Process plant;
Plant office;
Laboratory;
Mine workshop and offices;
Central control building; and
Each substation.
This will reduce wiring costs and allow voice messaging integration with e-mail. End-to-end IP video
connectivity with business quality transmission will provide video conferencing capabilities.
Satellite Communications
A satellite communications network will be provided for site-to-site communications between Toroparu
operations, Georgetown and outside of Guyana. The system includes voice/data/video/fax, internet,
and VPN services, including bidirectional links between the mine site and Georgetown.
Satellite phones will be installed at strategic areas for emergency communications.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 237/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 223
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Fiber Optic
The IT system will be based at the communications building and connected throughout the site by a
fiber optic network. The connection between IT devices and end-users will provide high through put,
secure, reliable and redundant service for data and voice. The network system will be connected to
protocol independent multicasts (PIMS) and business networks through routers with firewalls and will
provide remote access as required. The system will have security and encryption to prevent
unauthorized access.
18.1.8 Power Supply and Distr ibut ion
Due to the remote location of the Project, a site-based power plant is required. The power supply will
be provided via a series of interconnected 7.4 MW gen-set units generating power at 13.8 kV, 60 Hz.
Power distribution for the Project site will be by wooden pole overhead power lines from the substation
at the generator plant routed to the process plant, mine support area and camp. Transformers and
switchgear will be located at each of the buildings/facilities in the process plant with individual
transformers and switchgear and Motor Control Centers for the local power loads.
The power plant will be fueled by intermediate fuel oil specifically, IFO 180. The power plant will be
constructed in modules with the ability to add generators into the system as power demand grows.
Phase 1 of the Project will require a peak power demand of 22.4 MW to support the operation. This
peak demand increases to 26.7 MW during Phase 2 of the Project through the life of mine.
The power plant will have its own fuel storage facility with a one month on-site fuel storage capacity
for IFO 180 for continuous operation of the power station. One 1,000 m3 fuel oil storage tanks will be
built next to the power plant in Phase 1 and a second identical tank will be incorporated to support
Phase 2.
Typical voltages will be 4160 volts for motors greater than 200 kW and at 13.2 kV for the larger ball
mills. Additional transformers and electrical equipment will be provided for those electrical loads lessthan 200 kW at 480 volts.
Power for the entry station will be provided by a standalone diesel generator to be utilized on an as
needed basis. The Project will reuse the existing 1.5 MW unit for this supply.
18.1.9 Water Supply
Process Water
Initial fill for the process water requirements will come from the Wynamu River. Make-up water for the
process plant will be obtained by recycling decant water from the Tailings Management Area (TMA)
via a water reclaim system. A 190 m3 (50,000 gallon) water storage tank will be located at the plant
site.
Fire Water
Fire water for the plant facilities will come from the Wynamu diversion pond. The fire water shall be
distributed around the site in an arrangement to cover all the ancillary buildings, process plant, mine
support facilities, workshops and yard equipment. The systems are sized to provide four hours of fire
water demand and are fully integrated with a fire alarm and detection systems. Costs for a fire water
and protection system have been allocated in the estimate.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 238/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 224
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Potable Water
Drinking water for the man camp and plant site will come from rain water that will be collected from
camp building roofs. The building gutter system will convey the collected water to a screening and
filtration system where contaminants are collected and separated from the roof rain water collected.
Collected rain water from the site will be conveyed to a centralized potable water storage tank. A 284
m3 (75,000 gallon) water storage tank will be located at the camp site.
The water supply can be supplemented with river water from the Wynamu diversion pond during dry
periods. However, water from the river will need to be treated using a package plant to bring the water
up to drinking water standards. Ultrafiltration has been identified as the most effective means of
treating the Wynamu river water.
18.1.10 Waste Water Treatment and Solid Waste Disposal
Waste Water Treatment
Wastewater from the camp and process facilities will be treated using a package plant. Two dedicated
sewage treatment systems will be provided, one system for the man camp site and one system for theplant facilities area. The collected sewage will be transferred to packaged wastewater treatment
systems. Each system will be capable of treating 50,000 L of wastewater per day. Treated effluent
from the man camp facility will piped east of the camp facility and released into a local unnamed
tributary which will eventually flows into the Puruni River while the treated effluent from the plant area
location will be piped to the north and released into the Wynamu River. Sludge produced from the
wastewater treatment systems will be disposed of in the landfill with other waste material.
Solid Waste Disposal
It is assumed that non-recyclable, non-toxic solid waste will be disposed of at an onsite, lined landfill
to be sited and designed at a later stage.
18.2 Tailings Management Area
The TMA will be located on the northeast side of the Toroparu property. This facility will be staged and
operated in three independent cells as shown in Figure 18.2.1. The cells will operate separately at
different stages of the service life of the TMA as follows:
Cell 1 will operate up to the first quarter of Year 5 of full production;
Cell 2 will operate from the second quarter of Year 7 to second quarter of Year 9; and
Cell 3 will operate from the third quarter of Year 11 to end of the mine life at Year 16.
Detoxed tailings will be discharged into the TMA cells from the crests of the tailings dams, and
supernatant water volumes reclaimed to plant by a floating pump barge positioned on the decantponds of the cells. Excess water volumes will be discharged through spillways into three collections
ponds located adjacent to the cells for monitoring and control previous to release to the environment.
The design is based on the near surface ground conditions being sufficiently impermeable to prevent
ground contamination without a geosynthetic liner, and that the ground has sufficient strength to
support that perimeter dam slopes. Fill and compaction of in-situ saprolite was included in cost
estimates. The TMA has a storage capacity of up to 143 Mt. The tailings dry density estimate used for
the design was 1.30 t/m3.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 239/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 225
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The geotechnical conditions of the tailings site have been assumed from the geology information
previously described and from the results of the investigation program carried out by KCB (2012) at
the location of the tailings site defined in the PEA. A specific site investigation program for the tailings
site should therefore be carried out for the new location defined in this study during feasibility
engineering of the project.
18.3 Off-Site Infrastructure and Logist ic Requirements
18.3.1 Off-Site Infrastructure
Port Facilities
The port facility at Pine Tree Landing will be a key feature in the mine supply chain. Pine Tree Landing
is located on the right bank of the Cuyuni River, approximately 2 miles above the confluence with the
Mazaruni River, and has historically been used by logging companies as a shipping point for lumber
products and supplies. Pine Tree Landing is linked to the Toroparu Mine by the existing Upper
Mazaruni Development Authority & Toroparu Mine Road.
Currently, Pine Tree Landing has approximately 225 m of waterfront, and is cleared of vegetation for
approximately 500 m from the Cuyuni River, for a total area of approximately 32 acres. The existing
facilities are very limited and will not be reutilized.
The proposed port facility will generally include the following items:
Wharf;
Man camp;
Aggregate surfacing;
Container storage areas;
Bulk fuel handling infrastructure and storage;
Equipment laydown areas; Maintenance building;
Administration building;
Access control gate;
Lighting;
General civil infrastructure;
Security; and
Communications systems.
Mine fuel supply logistics and infrastructure will be provided by a contracted fuel supplier. Delivery will
be via supplier barge, and the supplier will construct the required infrastructure within the port facility
for offloading and storage of HFO and diesel. Initially, two 5,000 bbl tanks will be constructed,sufficient for an approximately 1 month supply of fuel during the mine construction phase. Expansions
of the depot will be made by the supplier as the mine progresses into start-up and expansion phases.
The tanks and infrastructure will include fire suppression and spill containment features.
The port facility will accommodate 1,000 ton barges which will transfer cargo between Georgetown
and Pine Tree Landing via the Essequibo, Mazaruni and Cuyuni Rivers. Containerized cargo is
anticipated to be approximately 45 containers import and 45 containers export per week. Cargo at the
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 240/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 226
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
port will be handled primarily with 40-ton forklifts and reach stackers. Heavy or oversized cargo will be
handled by a mobile harbor crane or as roll-off cargo.
Access Road
The existing roadway begins at Pine Tree Landing on the Cuyuni River and intersects the Upper
Mazaruni Development Authority (UMDA) road about 10 km west of Itaballi. At an intersection knownas Camp 4, located ~200 km (120 miles) west of Itaballi, the roadway continues north to the mine via
the Toroparu Mine Road, an approximately 30 km (20 miles) section constructed in the mid- 2000’s by
Sandspring.
The UMDA, established to administer infrastructure development funded by the United Nations
Development Program, constructed the existing road from the Mazaruni River village of Itaballi to
Kurupung in the mid-1970’s. The road is traveled today by a number of users, primarily mining and
logging related, and serves several small communities. The road is now identified as the Itaballi-
Puruni-Papishao Road by the Government of Guyana (GoG).
Upon cancellation of the UMDA hydroelectric projects in the late 1970’s, sections of the UMDA road
from Puruni Landing to Kurupung fell into disrepair. The establishment of the Toroparu explorationcamp by Sandspring’s Guyanese subsidiary, ETK, in 2001 was followed by the re-construction of
these road sections and the construction of a new road connecting the UMDA road to Toroparu.
The upgrade of the approximately 230 km (140 miles) roadway will generally include:
Brush back of vegetation;
Subgrade stabilization;
Installation or repair of culverts and bridges;
General grading and subgrade preparation earthwork;
Slope stabilization;
Fine grading; and
Production and placement of aggregate surfacing.
FMG conducted a reconnaissance of the roadway alignment in December of 2011. Escorted by
Sandspring personnel, an FMG engineer traveled the roadway from Itaballi to the Toroparu Mine over
the course of several days. The existing roadway conditions and features, including bridges, culverts,
soft subgrades, potential aggregate sources, and other pertinent information, were noted and
recorded. The Sandspring personnel provided insight into potentially applicable construction
techniques and specific upgrade concerns.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 241/340
Toroparu Gold Project,
Guyana
Figure 18.2.1
Tailings Management AreaSource: KCB, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 242/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 243/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 229
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
19.4 Contracts and Status
Currently there are no material contracts in place other than those disclosed in this document. It is
anticipated that the following contracts will be in place upon Project commencement.
19.4.1 Metal Treatment, Refining, and Transpor tation
Agreement for the secure transport of doré by air from Toroparu to refinery in North America
or Europe;
Agreement for the refining of gold doré and delivery to Sandspring’s designated bullion
account;
Agreement for the treatment & refining of copper concentrates;
Agreement for the transportation of containerized copper concentrates from Pine Tree
Landing to Georgetown, and transshipment for delivery to offshore custom smelter; and
Agreement for transportation insurance for export of precious and base metal cargoes.
19.4.2 Supplier & Service Contracts
Barge transportation of supplies between Georgetown Harbour and Pine Tree Landing;
Diesel and fuel oil supply and delivery to Pine Tree Landing;
Process reagents, consumables, and supply contracts;
Equipment preventive maintenance services;
Air transportation (Georgetown to site) services; and
Site security services.
19.5 Indicative Terms
Terms used in the development of financial estimates of revenue and costs are as follows.
19.5.1 Doré Net Smelter Return
Based on actual costs from other gold producers with similar sized operations:
Gold Payable: 99.9%
Refining Charge $0.65/oz Au
Secured air transport and Insurance $2.45/oz Au
19.5.2 Copper Concentrate Net Smelter Return
Based on indicative proposal received from multinational copper company:
Copper Payable 96.5% of contained Cu s.t. min deduction of 1%
Gold Payable: 97% of contained gold
Silver Payable: 97% of contained gold
Treatment Charge $95.00/t
(2012 benchmark + US$30/t)
Copper Refining Charge $0.065/payable lb Cu
Gold Refining Charge $6.50/ payable ounce of gold
Silver Refining Charge $0.65/payable lb Cu
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 244/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 245/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 231
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
20 Environmental Studies, Permitt ing and Social orCommunity ImpactSRK has prepared this section based on the work conducted by ETK and by Sandspring’s
consultants. ETK performed the baseline studies. KCB performed the geochemistry studies anddesigned the TMA and SRK designed the waste rock management facilities.
The Toroparu Gold Project is subject to a number of regulatory permits and licenses, issued by
several different governmental agencies. The Project has received its environmental permit for gold
and copper mining and processing based on a permit application dated May 2, 2008, and the
approved ESIA (ETK, 2012). The permit is valid from June 2012 through May 2017 and was issued to
ETK. Sandspring acquired ETK as part of its acquisition of GoldHeart Investment Holding Ltd. in May
2009, and thus the environmental permit is valid for Sandspring. The permit includes design,
operational and reporting compliance items.
Sandspring has signed a binding Memorandum of Understanding with the Government of Guyana that
grants exclusive right to evaluate and develop and hydroelectric power plant on the Kurupung River,
approximately 30 miles from the Project. A separate environmental permit will be required for the
hydroelectric power plant.
The applicable primary permit or license requirements are summarized in Table 20.1.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 246/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 247/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 248/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 234
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
variations in rainfall. The entire area identified for development into the mine, like the rest of Guyana
has a tropical climate and is not subject to extreme variations in temperature and humidity.
Sandspring maintained a weather station at the Project during 2005 and during discrete periods of
2005. Very little climate data are available locally. During the 2005 monitoring the maximum annual
precipitation was 2100 mm, and temperatures ranged from a low of 68 to a high of 108 degrees
Fahrenheit. The dry periods were January through March and August through October.
Winds were primarily from the north-northeast and the average maximum speed was 9.1 m/s. It is
generally windier during the short wet season.
It is recommended that monitoring at the weather station be re-established, and that the data collected
include evaporation information. It would also be helpful to have precipitation data recorded at
intervals less than 1 hour to understand the severity of storms.
Air Quali ty
In the area surrounding the Project site, there are no major industries that serve as significant sources
of fixed or mobile atmospheric emissions. Aerial emissions are mostly attributable to the gases from
rotting trees and other vegetative matter although some background emissions will inevitably berelated to the operation of various small to medium sized motorized equipment in the area. Due to the
high humidity and significant rainfall, dust levels on the roadways are generally low. Airborne
discharges and particulate matter are not monitored in the area but are not expected to exceed the
emission guidance established by the World Bank or WHO Ambient Air Quality guidelines.
Surface Water
The Toroparu Gold Project area is drained by the Puruni River and by several tributaries, the main
one being the Wynamu River. The total estimated drainage area of the Puruni River is approximately
4170 km2. Approximately 375 km2 of that drainage area is located upstream of the proposed mine
site.
In 2010, water quality samples were obtained at three upstream locations to assess background water
quality for the proposed mine. The surface water sampling locations are shown in Figure 20.1.1.1. The
water quality samples are demonstrative of water quality impacts from the former open pit mining
operation and are also indicative of water quality prior to the commencement of additional mining
operations. For comparison purposes the results were compared to the International Finance
Corporation (IFC) effluent requirements for mining operations (2007), because the Guyana EPA
guideline does not present permissible limits for water quality standards. The majority of the sample
results were below the IFC effluent requirements; however oil and grease and iron were exceeded in
one or more samples.
Groundwater
The site occurs in the Precambrian crystalline basement rock section of Guyana. Five groundwater
monitoring wells were installed to varying depths and at different locations during the first round of
investigations conducted at the concession. The locations of these wells are depicted as MW-1, MW-
2, MW-3, MW-4 and MW-5 on Figure 20.1.1.2. The location of each well, the top of casing elevation
and the static groundwater level, measured during each phase of baseline collection work at the site
are detailed in Table 20.1.1.1.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 249/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 235
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 20.1.1.1: Monitor Well Locations and Groundwater Elevation Data
WellIdentifier
Location (UTM) Top ofCasingElevation(masl)
Groundwater Elevation Measurement (masl)
Easting Northing 16/07/07 28/10/07 3/1/008 4/11/08 7/11/10
MW-1 824353 715217 32.87 31.70 31.04 32.03 30.48 32.20MW-2 825149 713946 31.27 30.26 No data 31.14 28.33 31.14MW-3 825948 713313 32.04 30.06 29.68 30.78 29.37 31.88MW-4 826293 714540 32.50 30.01 29.73 30.63 29.14 31.14MW-5 826854 713914 32.87 30.06 29.12 30.77 28.98 30.61
Source: ETK, 2012.Masl= meters above mean sea levelElevations are rounded to the nearest hundredth of a meter.
Groundwater levels recorded for the dry seasons are generally lower than those recorded for the wet
seasons. This can be interpreted as being indicative of precipitation being the primary source of
groundwater recharge in the Project area. No water was present in MW-3 during the second phase of
the field work, coinciding with conditions recorded in the long dry season.
Very little data are available on groundwater flow parameters for that section of Guyana. Observations
of remnant mines in the area indicate some groundwater inflow through the weathered unconsolidated
material overlying intact rock. That flow may, however, be reflective of recharge by precipitation.
Rising head in situ hydraulic conductivity tests were conducted in each monitor well after each
baseline sampling event. The hydraulic conductivities ranged from 9.75 x 10-5 cm/sec in MW-3 to
7.43 x 10-8 cm/sec in MW-5.
Groundwater samples were collected and analyzed according to the parameters mandated by the
Guyana EPA guidelines. The baseline results during the dry seasons were similar to those for the wet
seasons. The Guyana EPA guideline does not present permissible limits for water quality standards,
so for comparison purposes the results were compared to the International Finance Corporationeffluent requirements for mining operations (2007). Groundwater samples had slight exceedances of
Iron and pH and very high exceedances of total suspended solids. Iron ranged from non-detectable at
a detection limit of 0.03 mg/L to a high of 8.35 mg/L compared to the guidance value of 2.0 mg/L,
while pH ranged from 5.62 to 8.91 in comparison to the guidance value of 6 – 9 pH units. Total
suspended solids had very high exceedances ranging from 100 to 26,774 mg/L compared to a
guidance value of 50 mg/L. Since naturally-occurring groundwater typically would not exhibit high
levels of total suspended solids, SRK recommends that the sampling methodology and water
construction and development procedures be further reviewed to see if the well filter pack is
appropriate, the well development was adequate and the sampling technique is acceptable to
international standards.
Archaeological Resources
The site is located in the Middle Mazaruni area. The mine site would have been encompassed by
former Akawaio settlements and is contained within the Mazaruni Amerindian Reserve demarcated in
1904. This demarcation was reduced to the Upper Mazaruni Amerindian District in 1959. There are no
records of any immigrant activity in the area.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 250/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 251/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 237
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Herpetofauna
The relative species abundance determined during the survey indicates that the habitat may be ideal
for amphibians and reptiles. None of the species documented are endemic species or listed by
CITES.
Fauna Species of Interest
No locally rare, threatened or endangered species were recorded during the surveys; however a
number of species identified are listed by CITES. These along with other species listed by CITES and
their status are provided in Table 20.1.1.2.
Table 20.1.1.2: International Status of Species
Species Common Name International StatusLocal Status(Unofficial)
Caiman crocodiles Spectacle Caiman CITES Appendix II/III Fairly Common
Paleosuchus sp Dwarf Caiman CITES Appendix II/III common
Eunectes murinus Anaconda CITES Appendix II/III common
Epipedobates trivittatus Poison Frog CITES Appendix II/III Uncommon
Epipedobates sp Poison Frog CITES Appendix II/III Uncommon
Panthera onca JaguarCITES Appendix I, IUCNLower Risk- Near Threatened Species
Uncommon
Tapirus terrestris Lowland (Brazilian) tapir IUCN Lower Risk- Near Threatened SpeciesUncommon
Cebus olivaceus Wedged-capped Monkey CITES Appendix II/III Common
Saimiri scuries Squirrel Monkey CITES Appendix II/III Common
Agouti paca Labba CITES Appendix II/III Common
Oryzoborus angolensis Lesser seed Finch CITES Appendix I Uncommon
Amazona amazonica Orange-winged parrot CITES Appendix II/III Uncommon
Amazona farinosa Mealy Parrot CITES Appendix II/III Fairly Common
Amazona ochrophala Yellow-crowned Parrot CITES Appendix II/III Fairly Common
Ara chloropterus Red & Green Macaw CITES Appendix II/III Common
Brotogeris chrysoptera Golden Winged ParakeetsCITES Appendix II/III Common
Deroptyus accipitrinus Red-fan Parrot CITES Appendix II/III Common
Piontes melanocephalusBlack-headed Parrot CITES Appendix II/III Common
Pionus fuscus Dusky Parrot CITES Appendix II/III Common
Pionus menstruus Blue head Parrot CITES Appendix II/III Common
Pyrrhura picta Painted Parakeets CITES Appendix II/III Common
Pteroglossus aracari Black-necked Aracari CITES Appendix II/III Common
Source: ETK, 2012.CITES = Convention on International Trade in Endangered Species of Wild Fauna and Flora (2013). Classification includesthree CITES appendices:
Appendix I includes species threatened with extinction. Appendix II includes species not necessarily threatened with extinction, but in which trade must be controlled in order
to avoid utilization incompatible with their survival. Appendix III contains species that are protected in at least one country.
20.1.2 Results of Geochemical Studies of Tailings, Waste Rock and Low Grade Ore
The exposure of tailings, waste rock, open pit walls, the Low Grade Ore (LGO) stockpile, and tailings
to air and water may result in the generation of Acid Rock Drainage and Metal Leaching (ARD/ML).
Geochemical characterization studies were conducted by KCB from 2011 to 2013 (KCB, 2011, 2012,
2012a, and 2013) on the dominant bedrock lithologies representing waste rock and LGO, and
metallurgical tailings representing the three main ore types [that is, saprolite, Average Copper Ore
(ACO) and Low Copper Ore (LCO)], for ARD/ML potential. The geochemical characterization studies
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 252/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 253/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 239
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Mineralogy by Optical Petrography and X-ray Diffraction with Rietveld-refinement;
Net Acid Generation (NAG) tests; and
Shake Flask Extraction tests.
Optical petrography was completed by Mineral Services Inc. located in North Vancouver, Canada.
The X-ray Diffraction with Rietveld-refinement analysis was carried out by the Department of Earth
and Ocean Sciences, University of British Columbia, Vancouver, Canada. All other analysis and test
work was carried out by Maxxam Analytics located in Burnaby, British Columbia, Canada.
Metal Leaching Risk of Waste Rock and LGO
Results of the solid-phase elemental analysis indicated that the lithologies included high
concentrations of silver, arsenic, cobalt, chromium, copper, nickel, molybdenum, sulfur and selenium
in comparison to average crustal abundance of high-calcium granite. There was a wide variation
between the different lithologic units. The LGO samples indicated high solid-phase concentrations of
silver, copper, nickel, selenium and sulfur. Therefore the elevated concentrations of these elements in
the solid-phase may be at risk of leaching under site-specific field conditions.
The results of Shake Flask Extraction tests indicated elevated leachate concentrations of aluminumand selenium, relative to water quality guidelines, from non-saprolite waste rock lithologies and LGO
samples. The more aggressive NAG tests also indicated elevated chromium and copper in leachate
from one or more samples, relative to water quality guidelines. For the saprolite waste rock samples,
phosphorous, relative to water quality guidelines, was leached and readily soluble from Shake Flask
Extraction tests. For the more aggressive NAG test, chromium and silver were also leached and
readily soluble. With the exception of phosphorous, these leachate extraction test results are
consistent with elevated solid-phase concentrations of silver and chromium.
The NAG extraction test results reported concentrations of phosphorus, aluminum, chromium, copper,
selenium and silver were elevated above reference guidance using Canadian Council of Ministers of
the Environment water quality guidelines for the protection of aquatic life. The pH values for wasterock samples were above the guidance values, except for one saprolite sample that had a pH below
the guidance value of 6.5. The Shake Flask Extraction results indicated that phosphorus, aluminum
and selenium concentrations were elevated and that one sample had a low pH.
There are elevated concentrations of silver, arsenic, cobalt, copper, chromium, molybdenum, nickel,
selenium and sulfur compared to crustal rocks. The short-term leaching tests reported leaching of
aluminum, selenium, chromium and copper from non-saprolite waste rock. The saprolite waste rock
was observed to leach phosphorus, chromium and silver at concentrations above the aquatic life
guidelines.
Acid Rock Drainage Risk of Waste Rock and LGO
The paste pH results indicated that the major lithologies are alkaline with the exception of the saprolite
and the Transition Zone samples. The saprolite samples were slightly acidic to neutral while the
transition zone samples were neutral to alkaline. These results indicate that no acidity was released
from any of the samples except from the saprolite samples. The alkaline results indicate effective
carbonate buffering. The LGO samples are alkaline, which indicates a potential buffering capacity.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 254/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 240
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The waste rock sample results were low in total-sulfur and sulfide-sulfur content, and the associated
calculated sulfide-based Acid Potential (AP) values were also low. The LGO total-sulfur and sulfide-
sulfur contents and sulfide-based AP were also low.
The waste rock lithologies and LGO samples contained low to moderate Neutralization Potential, (NP)
with the exception of the saprolite and Transition Zone samples, which contained negligible NP. With
the exception of the saprolite samples, the Net Potential Ratio (NPR), the ratio of NP to AP, calculated
for the waste rock lithologies indicated that the waste rock was classified as not-Potentially Acid
Generating (N-PAG), and therefore have a very low potential to generate ARD. The Transition Zone
samples also had a low ARD potential. For the saprolite, most of the samples were Acid-Generating
(AG), although some were classified as Potentially Acid Generating (PAG) and N-PAG. The LGO
samples were N-PAG.
The NAG pH results confirmed the not-PAG ARD risk of waste rock and LGO samples. The saprolite
samples had the lowest pH results (5.9 and 6.8 pH units) whereas the other samples had NAG pH
results between 11.0 and 11.5 pH units. A NAG pH of 4.5 or less is indicative of PAG material. Based
on the results of the NAG tests, most of the samples had very low sulfide content and an abundance
of neutralizing minerals. The saprolite samples had mixed results regarding its potential to produceacid, but it was concluded to be most likely N-PAG due to its low sulfide-sulfur content (0.07% wt.).
Humidity cell testing was recommended to be completed to further assess metal leaching of waste
rock, LGO and open pit walls under alkaline conditions.
Tailings Geochemistry Testing and Results
Static testing was completed on six tailings samples and four supernatant samples by KCB (2013).
Three ore types (saprolite, ACO and LCO) were subjected to gravity separation, flotation and cyanide
leaching to create tailings of each ore type. The six tailings samples in the geochemical testing
included the following:
Two samples of ACO cleaner detoxified tailing pulp combined with rougher tailings;
One LCO rougher and cleaner composite tailings sample; and
Three saprolite samples (cleaner detoxified slurry, coarse cyanide leach slurry and coarse
flotation slurry).
The samples of these three metallurgical tailings streams (saprolite, ACO and LCO) were submitted
for geochemical characterization. The tailings samples were submitted for the following static and
leachate extraction tests:
Mineralogical analysis;
Solid-phase elemental analysis
ABA; and Supernatant aging tests.
All analysis and test work was carried out by Maxxam Analytics located in Burnaby, British Columbia,
Canada.
Metal Leaching Risk of Tailings
A screening level comparison of the elemental analysis of the tailings solids to three times average
crustal abundances indicated that silver, arsenic, bismuth, cadmium, cobalt, chromium, copper,
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 255/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 241
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
molybdenum, lead, antimony, tin, tungsten zinc were elevated and may be at risk of leaching under
site-specific field conditions.
A total of four tailings slurry samples, including two ACO, one LCO and one saprolite tailings slurry
sample following detoxification, were selected for an aging test of the supernatant to provide an
indication of how the quality of the TMA ponded water may vary over time. The aging tests were
conducted for a period of 90 days, with supernatant sampling analysis at 1, 7, 14, 21, 20, 60 and 90
days.
The tailings supernatant aging test results indicated that fluoride, nitrite, ammonium, CNWAD,
aluminum, arsenic, chromium, cobalt, copper, iron, molybdenum, and selenium concentrations were
above the Canadian and British Columbia water quality guidelines and therefore may be parameters
of environmental concern (KCB, 2013). Additionally, iron and CNWAD were elevated in LCO and/or
ACO tailings supernatant.
The TMA will receive a combination of precipitation, water treatment plant brine, and supernatant from
the tailings slurry. Although the metallurgical tailings leachate extraction test results indicated elevated
concentrations that may be soluble and mobile under laboratory test conditions, the results do not
imply that they will be elevated to levels above these guidelines under site-specific field conditions,
rather they identify elements that are prone to leaching. The TMA, will receive a combination of
precipitation, water treatment plant brine, and supernatant from the tailings slurry. The TMA water
quality will be influenced by contributions from all these sources. The TMA design assumes that the
natural low permeability of the surficial soils, and the lower concentrations of elements in the TMA
pond due to attenuation from natural degradation, settling, and mixing with precipitation, which
averages about 2.6 m annually, will reduce concentrations in any TMA discharge effluent to the
aquatic receiving environment. Additional analysis (i.e., predictive water quality modeling) will be
needed in a later phase to verify this assumption.
Additionally, the TMA management strategy of subaqueous tailings deposition combined with a
cyanide destruction goal of 0.5 mg/L may be sufficient to mitigate potential environmental impacts to
the aquatic receiving environment from effluent discharge from the TMA (KCB, 2013). Kinetic testing
was recommended to evaluate the behavior of the tailings under flooded conditions.
Acid Rock Drainage Risk of Tail ings
The ABA results indicated that all samples have a neutral to alkaline paste pH and an acid-buffering
capacity. However, the neutral to alkaline paste pH values are expected for metallurgical testing with
lime addition.
The total sulfur ranged from below the detection limit to 0.08% wt. Sulfur speciation analyses indicated
very low to negligible sulfide-sulfur concentrations with only one sample result reported above the
detection limit of 0.03% wt. The sulfide-based AP of all the tailings samples varied between 0.16 kgand 0.94 kg CaCO3/t, with a median value of 0.23 kg CaCO3/t, indicating a low sulfide reservoir to
oxidize and generate acidity. The inorganic carbon measured as CO2 varied between 0.010% and
2.49%. The corresponding Inorganic Carbon Neutralization Potential (Inorg-CaNP) ranged from 8.33
kg to 207.5 kg CaCO3/t, with a median value of 82.5 kg CaCO3/t.
The Sobek Neutralization Potential (NP) ranged from 10 kg to 134 kg CaCO3/t, with a median value of
56.9 kg CaCO3/t. The bulk of the Neutralization Potential appears to be from reactive carbonates
and/or the addition of lime during the metallurgical testing. The saprolite tailings samples contained
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 256/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 242
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
moderate NP (7 kg to 10 kg CaCO3/t) and the two copper ore tailings contained high NP (104 kg to
134 kg CaCO3/t).
The tailings samples were classified as not-Potentially Acid Generating (N-PAG) based on the sulfide-
sulfur values and are therefore considered to have negligible risk of ARD (KCB, 2013).
20.2 Environmental Issues Although additional studies are recommended to further develop mining waste management
strategies, there are no known environmental issues that could materially impact Sandspring’s ability
to extract the mineral resources or reserves at the site. Preliminary mitigation strategies have been
developed to reduce environmental impacts to meet regulatory requirements and the specifications of
the environmental permit.
20.3 Operating and Post Closure Requirements and Plans
The overall environmental management objective of the Toroparu Project is to use Best Available
Techniques (BATs), Best Management Practices (BMPs) and modern, proven technology to operate a
gold and copper mine, process plant, and supporting infrastructure consistent with the social,
economic and environmental requirements of the Government of Guyana and, to the extent that they
represent recognized international BMPs and World Bank/IFC/Equator Principles policies and
guidelines.
Sandspring will establish and maintain a documented, comprehensive Environmental and Social
Management System (ESMS) over the construction, operation and closure phases of the Project. The
ESMS will be based on current World Bank Group/International Finance Corporation guidelines.
The environmental permit requires a number of operating plans, including the Environmental
Management Plan components listed in the ESIA:
Open Pit Management
Overburden Management
Water Management
Tailings Pond Management
Hazardous Materials Management
Explosives Management
Cyanide Management
Waste Management
Spill Contingency Plan
Catchment Area Management
Social Management Plan Erosion and Sediment Control Plan
Land Reclamation and the Road Management Plan
The permit requires that a Health Safety and Environmental (HSE) officer be employed and be
responsible for the implementation of the Environmental Management Plan. In addition to the plans
listed above, the permit contained requirements for biodiversity protection and air quality
management.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 257/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 258/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 244
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 20.5.1: Summary of Socio-cul tural Impacts and Mitigation Strategies
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 259/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 245
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
20.6 Mine Closure
The overall intent of the closure plan is to achieve Project objectives for restoring the site and aquatic
environment to a high ecological value. The objectives of the closure plan are to:
1. Prevent, reduce or mitigate the adverse environmental effects associated with the Project;
2. Provide for the reclamation of all affected sites and landscapes to a stable and safe condition;3. Provide for the return of all affected ecosystems to healthy and sustainable functioning;
4. Reduce the need for long-term monitoring and maintenance by designing for closure and
instituting progressive reclamation;
5. Provide for long-term monitoring and maintenance of the sites affected by the Project as
required;
6. Provide for mine closure using the most current available proven technologies in a manner
consistent with sustainable development.
Closure will result in the establishment of conditions that support public safety through physical
stability (Physical Stability); it will encourage productive end land use by promotion of revegetation
and promote conditions for biological stability (Biological Stability); and will ensure that mechanismsare in place to protect water resources and the receiving environment, thereby providing chemical
stability (Chemical Stability). Performance standards related to physical, biological and chemical
stability would function as measures of accomplishment of the closure objectives. The Project
performance standards are as follows:
Physical Stability – Preservation of protective safety measures (in a state in which the measures
can be effective) throughout the post-closure monitoring period, once there has been no external
human influence.
Biological Stability – Effective revegetation and restoration evidenced by vegetative proliferation
on 70% of the site areas intended for revegetation by the end of the post-closure monitoring
period.
Chemical Stability – Water quality similar or improved when compared with historic data at the
end of the post-closure monitoring period, once there has been no human or related influence.
The conceptual closure activities incorporate strategies to protect surface water and groundwater;
prevent erosion and control discharge from reclaimed mine facilities; and protect wildlife, as outlined
below.
The storm-water management practices will provide systems that minimize environmental damage by:
Maximizing retention time within the system by use of detention ponds
Minimizing increases in surface runoff flow and volume
Channeling and diverting runoff Use of bench terraces
Soil conservation techniques to be employed to ensure closure success include
Modifying the soil slope
Maintaining and establishing natural vegetative cover
Securing favorable soil conditions to facilitate vegetative growth
Wildlife conservation techniques will include:
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 260/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 246
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Providing food resources through establishment of vegetation
Providing habitats for wildlife through encouragement of vegetative proliferation, as well as
creation of aquatic habitats
Providing surface water and soils of good quality for wildlife consumption and use.
The approved environmental permit requires the submittal of a detailed closure plan for agency review
and approval two years in advance of closure.
20.7 Reclamation Measures during Operations and Project Closure
The facilities will be progressively closed over the duration of the mine site operations. Progressive
closure will reduce the costs of reclamation since closure will be integrated with the production
operations. In addition progressive closure will result in the development of expertise on the most
appropriate reclamation methods. Progressive closure will be undertaken, however without posing
impediments to day-to-day operations of the site. Final closure of the mine site will be undertaken
following completion of all mining operations, once treatment of site waters is no longer required, and
indications that further mining of the Toroparu Mine is not warranted.
Final closure of the facility will occur in two stages. The first stage will entail the following activities, if
not undertaken during progressive closure phases:
All fuel, chemicals, waste hydrocarbon products, and any potentially hazardous materials will
be removed from this site;
Water treatment will cease once runoff water no longer requires treatment.
During the second stage of the final closure all equipment, machinery, and storage tanks will be
removed for reuse or recycle. Where such uses are not practical, any remaining such materials will be
disposed of at a suitable storage site. All structures will be removed and/or be demolished. Structures
that are suitable for reuse or recycling will be salvaged. Structures not suitable for use will be
disposed. The Tailing Management Areas (TMAs) and other water management ponds will be closedand all disturbed areas will be reclaimed, with the exception of roads needed for monitoring access.
After the major closure activities are complete, a monitoring program may be implemented including
the site water quality monitoring and dams inspections.
The conceptual closure plan is intended to ensure the “return to nature” of the mine site. At the
conclusion of the closure process, no buildings or supporting infrastructure or facilities would remain
at the site. The areas will be fully replaced by a sustainable environment comprised of productive and
diverse lake and pond ecosystems. Spoil piles, stockpiles, borrow areas etc. would be vegetated with
general sustainable grass as well as emerging forest (primarily early stages in rainforest succession
are expected to dominate the period immediately following closure). The site will be monitored for
success of the closure plan. A few routes will be left for access to points of interest for the monitoringprogram. These routes will be closed after successful reclamation.
20.7.1 Tailings Management Area
The conceptual closure method for the tailings will include progressive closure of Cells 1 and 2. Any
exposed beaches will be reclaimed by placing a saprolite cover 1.0 m thick on the top of the tailings
beach and an additional layer 0.3 m thick of topsoil above the saprolite. The topsoil will be amended
by seeds and fertilizer. Rock armor will be placed on the side slopes. Diversion channels will be
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 261/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 247
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
redirected to flow back into the TMA. In the case of a precipitation event that exceeds design criteria,
discharge will be routed down spillways into the three collection ponds that will remain after closure.
The tailings facility design is based on a final slope that will be stable, thus no additional contouring of
the slope is anticipated at closure.
20.7.2 Open PitsPit banks must be structurally stable and barriers will be constructed around the parameter of the pit
for safety. A perimeter berm and fence will be placed around the open pit, and the earthen berm will
be revegetated. The berm will be to prevent vehicles from entering the pit except at a designated,
locked access point. The fence will be used to prevent unauthorized access. It is assumed that any
future pit lake will not require water quality management activities; however additional assessment will
be required to predict future pit lake conditions and the need for post-closure treatment or
management.
20.7.3 Waste Rock Storage Areas
The waste rock facilities will be covered with about 0.3 m of saprolite. The waste rock areas will beconstructed based on final slopes that will be stable, hence no additional contouring of the slopes is
anticipated.
20.7.4 Plant Site and Facilities
All plant and related facilities will be dismantled or demolished. Concrete slabs and footings will be
broken up to allow for infiltration, or will be placed into open facilities such as ponds or onto the waste
rock facilities. Power and water lines will be disconnected and will be removed from the site. Useful
major equipment and material will be salvaged and sold to third parties. Foundations will be removed
and excavated areas will be filled with native topsoil to restore naturally-sloping topography, where
feasible. Facility sites will be graded to blend in with existing topography, and compacted areas will be
ripped and the whole area will be covered with topsoil and revegetated. All topsoil areas will be
regraded and revegetated. Covers will be installed using saprolite available at site.
Several roads will remain to provide access to the property for closure and post-closure monitoring.
Internal roads will be leveled and graded to facilitate vegetation growth and re-establish drainage. All
exploration roads at the mine site will be reclaimed in a similar manner to haul and access roads. This
will include all areas outside the active mining area.
20.8 Closure Monitoring
Surface water and groundwater quality will be monitored after closure for evidence of environmental
impacts. Water samples will be collected annually to establish water quality trends. Physical
inspections will be conducted to monitor the physical stability of remaining facilities and the condition
of the closure covers and revegetation. It is anticipated that physical inspections will take place
quarterly and after significant storm events. Environmental monitoring is assumed to continue for ten
years, or until non-hazardous conditions are achieved for any discharge from the remaining facilities
and the groundwater and surface water quality meets applicable regulatory standards. Monitoring
records will be maintained by the mine operator.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 262/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 248
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
20.9 Reclamation and Closure Cost Estimate
An allowance of US$16,162,501 for the final cost of reclamation and closure of the property has been
included in the cash flow projection.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 263/340
Toroparu Gold Project,
Guyana
Figure 20.1.1.1
Location of Surface Water SamplesSource: ETK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 264/340
Toroparu Gold Project,
Guyana
Figure 20.1.1.2
Location of Well SitesSource: ETK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 265/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 251
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
21 Capital and Operating Costs [All]
21.1 Summary
The total estimated initial cost to design and build the Toroparu Project identified in this report is
US$464 million. A summary overview of the estimate by area is presented in Table 21.1.1.
Table 21.1.1: Summary of Capital Costs by Area
PFS Capital Cost Estimates(US$ Millions)
ScopeInitial Capital
(Pre-Prod)Expansion and
Sustaining CapitalLoM Capital
Fresh Rock Pre-Stripping SRK $24 $0 $24Mine Site Preparation / Roads SRK $2 $0 $2Mining Equipment SRK $69 $168 $237Milling Circuit Tt $75 $0 $75Leaching Circuit Tt $36 $0 $36Flotation Circuit Tt $24 $0 $24Process Plant Infrastructure Tt $6 $0 $6Plant Expansion Tt $0 $50 $50
Tailings Storage Facility Tt/KCB $16 $63 $80On-Site Infrastructure Tt $11 $11 $22Power Generation Tt $27 $0 $27Water Management Tt $9 $0 $9Camp and Ancillary Buildings Tt $25 $0 $25Port and Logistics FMG $9 $0 $9
Access Road Upgrades FMG $33 $0 $33Construction Indirects (incl. EPCM) Tt $79 $0 $79Owner's Costs (Incl. Closure) Sandspring $20 $15 $35
Sub-Total Project Capital Costs $464 $307 $771Mining Contingencies (Site Prep + Equip) SRK $4 $8 $12Process and Infrastructure Contingencies Tt/KCB/FMG $32 $0 $32Owner’s Costs Contingencies Sandspring $2 $4 $6
Total Contingencies All $37 $13 $50
Total Capital Requirement All $501 $319 $821Contribution from Saprolite Au Ore Margin All ($37) $0 ($37)
Total Project Costs w/ Contingencies All $464 $319 $784
The aggregate capital estimate is considered to be within a +30% / -25% weighted average accuracy
of actual costs. Base pricing will be in Q1 2013 United States dollars, with no allowances for inflation
or escalation beyond that time.
The contingency cost is based on the total direct and/or indirect costs and are included to account for
unanticipated costs within the scope of the estimate. The contingency percentage allowances vary
and are individually assessed based on the accuracy of the quantity measurement, type and scope of
work, and price information for the capital cost estimate.
The estimate is based on the cost of new equipment supported by budget quotes from vendors which
do not reflect discounts for negotiated prices, bulk purchasing, or used equipment purchases where
appropriate, any of which could lead to reductions in actual capital costs relative to the prices used in
the capital estimate.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 266/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 252
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Each contractor used their standard estimating system to calculate its respective capital costs for the
Project. The resultant information of the direct costs, together with the indirect costs is presented in
this section.
21.2 Capital Cost Estimate
21.2.1 Mining Capital Cost
Mining capital includes US$24 million of pre-stripping. Major mining capital costs were categorized
into mine equipment (estimated by SRK Consulting) and mine support facilities (estimated by Tt). The
mining equipment requirements were based on the mine production schedule, and estimates for
scheduled production time, mechanical availabilities, equipment utilization, and operating efficiencies.
Estimates of annual operating hours for each type of equipment were made, and equipment units
were utilized in the mining operations until a unit reached its planned equipment life, after which a
replacement unit was added to the fleet, if necessary. Additional equipment units and replacement
units were calculated as sustaining mining equipment capital costs. Major mining equipment rebuild
(overhaul) costs were not included in the mining equipment capital cost estimates, and were includedin the mining operating costs.
Capital cost estimates for major mining equipment (drills, loading equipment, haul trucks, dozers,
graders, etc.) were based on quotes from equipment manufacturers. Capital cost estimates for mining
support equipment were based on the current Infomine (mining) cost reference guide.
With the introduction of mining equipment in the second and third preproduction years (Years -2 and -
1), a cost estimate was made for the purchase of new spare parts, which was equivalent to 5% of the
total cost of the mining equipment purchased in those two years. A cost estimate was made for mine
shop tools, which was US$1.643 million.
The mining equipment capital cost estimate was based on the following:
All mining units are based on new equipment purchases;
Freight cost for major mining equipment was generally estimated between 4% and 7%;
No import duties were deemed to be applicable;
Allowances were made for on-site equipment erection costs for particular units;
Allowances were included for customization of the equipment (fire suppression, A/C, etc.);
Mining equipment rebuilds (overhauls) were included in mining operating costs;
The mining equipment capital cost estimate includes US$3.207 million for initial spare parts;
The mining equipment capital cost estimate includes US$1.643 million for shop tools;
The mining equipment capital cost estimate includes US$0.475 million for shop tools;
The total mining equipment capital cost estimate has an added 5% contingency; and The mining equipment capital cost estimate shown in this section does not include the mining
support facilities (infrastructure).
Table 21.2.1.1 shows the mining equipment capital cost estimate for Years -2 and -1, for the initial
capital costs.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 267/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 253
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 21.2.1.1: Initial Mining Equipment Capital Cost Estimate (US$000s)
Unit -2 -1 -2 -1 Total Initial
Equipmen t Units Make Model SizeCost
US$000sUnits Units
CostUS$000s
CostUS$000s
CostUS$000s
DrillingBlasthole drill - new Atlas Copco PV-235-D 165mm 2,000 2 3,999 3,999BlastingBlasting flatbed truck Scania G360CB 4X4 214 1 214 214
ANFO/Emulsion truck Scania P360CB 6X4 13 tonne 421 1 421 421Blasters crew truck Manufacturer 4x4 54 1 54 54Blasthole stem truck Scania P360CB 6X4 291 1 291 291LoadingFront end loader Caterpillar 988H 6.4 cu m 913 2 1,827 1,827Front end loader Caterpillar 993K 12.2 cu m 2,147Hydraulic excavator Caterpillar 390DL 5.0 cu m 1,117 3 4 3,351 4,468 7,819Hydraulic exc/shovel Caterpillar 6018EX/FS 10.0 cu m 3,284 2 6,568 6,568Hydraulic exc/shovel Caterpillar 6040EX/FS 22.0 cu m 7,495HaulingHaul truck - new Caterpillar 740B 40 tonne 889 4 3,554 3,554Haul truck - new Scania G460CB 10X4 50 tonne 390 9 34 3,512 13,267 16,779Haul truck - new Caterpillar 785D 133 tonne 2,478Other Mine EquipmentCrush/Screen Plant Manufacturer Jaw/Cone 335 kW 1,320 1 1,320 1,320Track dozer - new Caterpillar D9T 306 kW 997 4 3,988 3,988Wheel dozer - new Caterpillar 844H 468 kW 1,351 1 1 1,351 1,351 2,701Motor grader - new Caterpillar 16M 221 kW 1,134 2 1 2,268 1,134 3,402Backhoe loader Caterpillar 450E 102 kW 155 1 155 155Water truck - new Scania P410CB 8X4 30,000L 276 1 1 276 276 552Excavator - new Caterpillar 374DL 355 kW 786 1 1 786 786 1,572Compactor - new Caterpillar CS/CP 54 97 kW 166 2 332 332Support EquipmentTransport/mover Manufacturer Model 360 tonne 1,350 1 1,350 1,350Truck crane Manufacturer Model 120t crane 1,134 1 1,134 1,134Recovery truck Scania G460CB 8X8 360 kW 840 1 840 840Control blasting drill Atlas Copco SROC D65 110 mm 1,452 1 1,452 1,452Secondary blast drill Manufacturer 75 kW 64 mm 144 1 144 144Fuel/lube truck Scania P410CB 8X4 30,000L 482 1 482 482HD mechanic's truck Scania P360CB 6X4 310 1 310 310Flatbed truck Scania P360CB 6X4 19t crane 263 1 263 263Welding truck Manufacturer Model 75 1 75 75Tire service truck Scania P360CB 6X4 460 1 460 460Forklift Manufacturer Model 193 1 193 193Pit pumps/generators Flygt/Gen BS2290-434 82 kW 70 4 278 278Pit pumps & engines Godwin/Cat HL260M/C18 430 kW 138 2 277 277Personnel van/bus Manufacturer Model 64 5 321 321Service pickup Manufacturer 4x4 48 5 10 241 482 722Light plant Manufacturer Portable 8 kW 24 10 235 235Total Initial Mobile Equip 70 58 41,063 23,019 64,082Major equip initial spare parts 3,207 3,207Mine shops tools 1,643 1,643Tech services equipment 475 475Total Other Equipmen t 5,325 5,325Total Initial Mining Equip 46,388 23,019 69,407Contingency (5%) 2,319 1,151 3,470Total Initial Capital W/Cont 48,707 24,170 72,877
Pre-stripping
Mining capital includes US$24 million of pre-stripping. This cost is not mining equipment and is not
included in Table 21.2.1.1
Pre-Production Clearing
This cost is not mining equipment and is not included in Table 21.2.1.1. The mining capital estimate
includes US$0.25 million allocated to the clearing of the Toroparu Pit area, so that mining equipment
will be able to access the area to construct haul roads and commence mining of saprolite waste.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 268/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 254
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Initial Haul Roads
This cost is not mining equipment and is not included in Table 21.2.1.1. The mining capital estimate
includes US$1.50 million allocated to the construction of initial haul roads around the mine site area.
Approximately 5 km of haul roads will be required, mainly for the 50 t capacity haul trucks used in the
earlier years of production.
The mining equipment capital cost includes a jaw and cone crushing and screening plant, which will
provide crushed rock for road surfacing.
Subsequent (ongoing) development of haul roads, and upgrading of the roads later in the mine life for
the 133 t capacity haul trucks is included in the mining operating costs.
Mining Support Facilities
The following items are included in the mining support facilities and are part of the on-site
infrastructure costs:
Mine equipment maintenance shops;
Mine equipment wash pad; Mine equipment fuel storage and station; and
Explosives magazines.
The mining equipment capital estimate includes US$1.643 million allocated to maintenance shop tools
and equipment and is included in Table 21.2.1.1.
Engineering Equipment, Hardware & Software
The technical services department (geology, mine engineering and surveying) will require certain
equipment, computer hardware and software. The mining equipment capital estimate includes
US$0.475 million allocated to this.
21.2.2 Process and On-Site Infrastructure Capital Cost
Tt prepared a capital cost estimate to include the costs to design, construct, install, and commission
the mine and process support facilities, process plant, TMA facilities and associated on-site
infrastructure. The total costs for Tt’s design is estimated to be US$334.4 Million (Table 21.2.2.1). This
amount includes the direct field costs of executing the Project plus indirect costs associated with
design, construction, commissioning and contingency. Base pricing will be in Q1 2013 United States
dollars, with no allowances for inflation or escalation beyond that time.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 269/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 255
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 21.2.2.1: Initial Capital Cost Estimate – Process and On-site Summary
Area Total (000’s) Direct Costs
Overall Site $10,983Process Plant $140,419Power Supply $26,525
Water Management & Treatment $6,063Dewatering Flood Protection $3,037Tailings $16,422
Ancillary Buildings $24,772Direct Costs Subtotal $228,221
Indirect Costs Project Indirects $78,545Indirect Costs Subtotal $78,545
Contingency
Contingency Subtotal $27,677Total $334,443
Estimate Base, Date and ValidityThis estimate has been prepared in accordance with the Class 4 Feasibility Cost Estimate standards
of the Association for the Advancement of Cost Engineering International (AACE). The accuracy of
the estimate is +35%/-25%.
The quotes used in this study estimate are budgetary, sufficient to support a preliminary feasibility
study, and were obtained in Q4 2012. Quotations are non-binding. The estimate was prepared with
United States dollars as the base currency. Foreign exchange rates were not used.
Cost Basis
The direct cost estimate performed by Tt encompasses the costs associated with the overall site
infrastructure, the processing plant facility, power supply, the water management, dewatering andflood protection systems, and the tailings management area.
Tt worked in cooperation with Sandspring to identify key locations of site infrastructure, water
management placements, and the process design. Sandspring provided the baseline and input data
necessary for Tt to perform supporting calculations in the form of material quantities, for each of the
above items.
The processing plant consists of the comminution circuit, flotation and regrind circuit, pre-leach
thickening and CIP circuit, carbon elution and electrowinning, reagents and utilities.
The support infrastructure facilities provided include a change house, administration building,
laboratory, heavy and light equipment shops, warehouse facilities; truck wash facility, fuel dispensing,
ready line and explosive storage area.
The additional on-site infrastructure includes site development, roads, fresh water supply pond, yard
services, power generation and distribution, and fuel storage depot.
The tailings management area (TMA) consists of a tailings disposal pipelines, dam, water reclaim
pipelines, pump system and secondary containment facilities.
Environmental facilities consist of sewage treatment, water management dams and channels,
stormwater collection ponds and pumping stations or pass through gates.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 270/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 256
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The following entities have the responsibility for the above areas:
Tt: Complete ore processing facility with the exception of the comminution circuit. Tt is also
responsible for the on-site infrastructure water management protections and tailings and
water reclaim pipe lines;
Jacobs Engineering: Preliminary development and selection of the comminution circuit
inclusive of the primary crushing, ore storage and reclaim, secondary crushing, HPGR circuit.
The costs include all earthworks, foundations structural steel, and bulk commodities
consistent with a turn-key package. Tt adapted the HPGR circuit into its overall process
design; and
KCB: Complete TMA facility inclusive of all site development (cell and pond configuration),
dam structures, service roads and bridges, and internal water and tailings management
pipelines. The KCB developed quantities were provided to and priced by Tt.
Exclusions
The following items are excluded from Tt’s capital cost estimate:
working or deferred capital;
financing costs;
refundable taxes and duties;
land acquisition;
currency fluctuations;
lost time due to severe weather conditions;
lost time due to force majeure;
additional costs for accelerated or decelerated deliveries of equipment, materials, or services
resultant from a change in Project schedule;
warehouse inventories, other than those supplied in initial fills;
any Project sunk costs (studies, exploration programs, etc.); mine reclamation costs;
mine closure costs;
escalation costs; and
community relations.
21.2.3 Off-Site Infrastructure Capital Cost
Port Facilities
The initial capital costs for the port facility at Pine Tree Landing were developed by FMG, Inc. and port
sub-consultant Cargo Velocity, LLC, and are summarized in Table 21.2.3.1.
The port facility study considered three wharf concepts to observe the cost implications of differing
barge berthing options. All three wharf concepts facilitate the handling of the anticipated cargo types
and volume and apply the same backland infrastructure concept. For its lowest expected capital and
operating costs and lack of tidal range restrictions, a concrete ramp wharf concept is preferred and
considered in the port capital cost estimate.
The port capital costs, including contingencies are estimated to be US$10.4 million and include:
Backland infrastructure;
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 271/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 257
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Wharf; and
Mooring facilities.
Excluded from the capital costs are:
Cargo container inventory;
Barge costs; Container chassis; and
Reefer mobile generators.
Access Road
The capital and operating costs to upgrade and operate the Toroparu Mine Road were developed by
FMG, Inc. through consultation with the Sandspring road maintenance crew supervisor. Sandspring
constructed the portion of the Toroparu Mine Road from Camp 4 to Toroparu in the mid-2000’s and
has been maintaining and upgrading portions of the roadway from Itaballi to Toroparu continuously
since 2011. Currently, Sandspring maintains a man camp near the Kumung River from which it bases
localized road maintenance operations which include: grading, placing aggregate surfacing, repairing
bridges, stabilizing soft sections and installing culverts. Thus, Sandspring has accumulated a direct
knowledge of the capital costs of roadwork along the Toroparu Mine Road.
The following components formed the basis of the capital cost estimate:
Equipment/Infrastructure;
Brush Back;
Culverts;
Single-Span Modular Steel Bridges;
Multi-Span Modular Steel Bridge;
Long-Span Modular Steel Bridges;
General Earthwork; Slope Stabilization;
Aggregate Surfacing;
Signage; and
Road Camp.
The initial capital requirement for the upgrade of the Toroparu Mine Road from the proposed port at
Pine Tree to Toroparu, including contingencies, is estimated at US$35.5 million. A contingency of 5%
was assigned to all direct costs for which Sandspring has demonstrated cost experience through their
current maintenance efforts. A contingency of 20% was assigned to the Furnishing and Placement of
Aggregate Surfacing. Although Sandspring has performed reconnaissance for laterite and fresh rock
occurrences and identified sufficient volumes, some variability is perceived in the processing andtransport costs for this item.
The Off-site Infrastructure Capital Cost Estimate is summarized in Table 21.2.3.1.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 272/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 258
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 21.2.3.1: Off-site Infrastructure Capital Cost Estimate (US$ mill ions)
Capital Cost Port Facility Access RoadDirect 7.4 31.5Indirect 1.5 1.3Contingency 1.6 2.7Total Capital Costs 10.4 35.5
Source: FMG, Inc., Cargo Velocity, Inc., Sandspring 2013
21.2.4 Owner’s Cost
Owner’s costs have been developed by Sandspring and the summary of these costs during the
construction period are shown in Table 21.2.4.1. The cost is broken down for the various core activity
areas and for the additional activities that are specific to the Toroparu Project.
Table 21.2.4.1: Major Components of Owner’s Costs ($US mill ion)
Item $US (milli on)Material Transport Equipment 4,350
Owner’s Development Team 4,705Construction InsuranceOwner’s G&A
7,2703,616
Contingency 1,912Total Owner’s Cost: 21,853
*All figures in million US$
Material Transport Equipment
The initial capital requirement for the fleet required to transport equipment and construction materials
to site from the proposed port at Pine Tree to Toroparu is estimated at US$4.35 million. A contingency
of 8% was assigned to the equipment purchase costs, for a total of US$4.7 million.
Transportation equipment requirements were based on an estimate of the number of trips required per
day for the transportation of fuel, containerized supplies (reagents, consumables, and materials),
during full production and acquiring these units in the first year of pre-production to provide
transportation for construction equipment, materials, and supplies to site.
Owner’s Development Team
This is a temporary department, during only the development phase of the Project. It is composed of
the Owner’s team, during the EPCM phase of the construction. Areas of responsibility include Project
controls management, construction management, engineering management, cost control, and
contracts. The role of this team ceases after operations start-up. The cost for this function is
US$4,705 million. An additional 10% contingency was added.
Construction Insurance
Insurance costs during construction are estimated at US$7,270,000 over the three year construction
period. The basis was a quotation received from a major North American construction brokerage firm.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 273/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 259
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Owner’s G&A
The majority of the Owner’s G&A Cost is due to Personnel in Administration functions, such as
management, finance, accounting, IT, supply chain, human resources, environmental, health, safety
and security and camp cost for all these functions during the construction period.
21.2.5 Sustaining Capital Costs
Mining Sustaining Capital
The LoM mining sustaining capital primarily consists of additional and replacement mining equipment.
The LoM mining sustaining capital estimate is as follows:
LoM additional and replacement (sustaining) mining mobile equipment - US$163.835 million;
LoM mining other equipment (large equip. spares parts, dispatch system) - US$4.218 million;
LoM sustaining mining equipment contingency (5%) - US$8.403 million; and
LoM total sustaining mining equipment including contingency - US$176.455 million.
These estimates are detailed further in this section. Mining sustaining capital costs occur between
Year 1 and 14. There are no mining sustaining capital costs in Year 15 and after.
A mine dispatch system capital cost estimate was included as sustaining capital in Year 2 of full
production, when the mining operations are planned to have expanded. With the introduction of larger
mining equipment in Year 6, a sustaining capital cost estimate was made for the purchase of
additional spare parts for this equipment, which was US$2.385 million.
Other mining related sustaining capital cost includes in Year 6 a third maintenance shop facility
planned to be constructed for the 133 t haul trucks, which will consist of four bays. This is included in
the Infrastructure sustaining capital cost.
As previously mentioned, the mining equipment rebuilds (overhauls) were included in mining
operating costs. Table 21.2.5.1 shows the LoM mining equipment sustaining capital cost estimate.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 274/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 275/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 261
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Process Systems Sustaining Capital Costs
The process systems sustaining capital is the costs associated with the expansion to the process
circuit and are inclusive of the following:
7,500 t/d gravity feed circuit – US$213,000;
CIP circuit area expansion – US$17,594,000; HPGR comminution circuit additional – US$30,943,000; and
Tailings pump expansion – US$793,000.
The total sustaining cost for process systems is estimated to be US$49,543,000. These sustaining
capital costs occur between production Years 3 and 5. There is no anticipated process system
sustaining capital costs after production Year 5.
TMA Facilities Sustaining Capital Costs
The TMA facilities sustaining capital is the costs associated with the expansion to the TMA cells and
containment ponds and are inclusive of the following:
Internal access road cell 1 – US$203,000; Internal access road cell 2 – US$1,997,000;
Internal access road cell 3 – US$415,000;
Cell 1 development – US$1,571,000;
Cell 2 development – US$9,353,000;
Cell 3 development – US$25,455,000;
Collection pond - cell 2 – US$2,736,000;
Collection pond - cell 3 – US$509,000;
Hydraulic deposition of soil cover – US$6,651,000; and
Pipelines & reclaim barges – US$14,466,000.
The total sustaining cost for TMA facilities is estimated to be US$63,356,000. These sustaining capital
costs occur between production Years 2 and 14. Table 21.2.5.2 shows the distribution of these costs
over this time frame. There are no anticipated TMA facilities sustaining capital costs after production
year 14.
Onsite Infrastructure Facilities Sustaining Capital Costs
The onsite infrastructure facilities sustaining capital is the costs associated with the expansion to the
main and satellite pits and mining operations. These costs are inclusive of the following:
Dewatering Pumps - Main Pit – US$4,651,000;
Dewatering Pumps - Satellite Pit – US$978,000;
Mine Shop Expansion – US$770,000; and Power Station Expansion – US$4,854,000.
The total sustaining cost for the onsite infrastructure facilities is estimated to be US$11,253,000.
These sustaining capital costs occur between production Years 1 and 16. Table 21.2.5.3 shows the
distribution of these costs over this time frame. There are no anticipated onsite infrastructure facilities
sustaining capital costs after production Year 16.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 276/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_ML
Table 21.2.5.2: TMA Facilities Sustaining Capital Cost Estimate
TMA FacilitiesSustaini ng Capital by Operating Year ($000s)
1 2 3 4 5 6 7 8 9 10 11 12
Area 4,021 13,758 4,498 4,930 18,481 6,472 6,298
Internal Access Road Cell 1 203Internal Access Road Cell 2 1,733 264
Internal Access Road Cell 3 318 Cell 1 Development 1,571Cell 2 Development 6,988 2,365Cell 3 Development 17,168 4,892 Collection Pond - Cell 2 2,736Collection Pond - Cell 3 509Hydraulic Deposition of Soil Cover 3,384 3,267Pipelines & Reclaim Barges 2,247 2,301 1,114 2,301 486 3,205 1,406
Values are rounded to the nearest thousand dollars
Table 21.2.5.3: Onsite Infrastructure Sustaining Capital Cost Estimate
Onsite Infrastructure Facilities
Sustaining Capital by Operating Year ($000s)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Area 5,506 280 770 296 326 815 3
Dewatering Pumps - Main Pit 280 296 815 3Dewatering Pumps - Satellite Pit 652 326Mine Shop Expansion 770Power Station Expansion 4,854
Values are rounded to the nearest thousand dollars
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 277/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 263
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
21.3 Operating Cost Estimates
21.3.1 Summary
The PFS estimate is based on independent reputable vendor quotations and where not available, first
principal calculations completed by the Consultants. Each contractor used their standard estimatingsystem to calculate its respective operating costs for the Project.
Operating costs have been prepared in Q4 2012 US dollars and exclude:
Contingency;
Escalation;
Taxes (VAT); and
Import Duties.
Imported equipment, materials, and operating supplies are not subject to Taxes (VAT), import or other
duties as per the Mineral Development Agreement.
The operating cost estimates have been assembled by area and component, based upon estimatedstaffing levels, consumables and expenditures according to the mine and process design. Life-of mine
operating costs are shown in Table 21.3.1.1, and annual operating costs in Table 21.3.1.2 (rounded to
nearest US$1,000).
Table 21.3.1.1: Operating Cost Life –of Mine, US$ x 1,000
Area Labor ($000s) Expenses ($000s) US$/t-Mined US$/t-Mi ll
Mine 159,656 946,003 1.86 8.70
Processing 22,238 1,313,509 n/a 10.51
G&A 92,515 81,306 n/a 1.37
Total Operating 274,408 2,340,818 n/a 20.57
n/a=not applicable
Table 21.3.1.2: Annual Operating Cost, US$ x 1,000
Year Mining Processing G&A Total $/t-milled
1 64,209 89,615 25,268 179,092 21.332 62,516 66,626 10,639 139,781 23.213 65,722 66,370 10,643 142,735 23.824 71,999 86,342 10,694 169,035 20.425 67,618 86,342 10,460 164,420 19.876 83,639 86,342 10,459 180,440 21.807 94,336 86,342 10,538 191,216 23.108 104,999 86,342 10,605 201,946 24.409 93,772 86,342 10,168 190,282 22.99
10 91,530 86,342 10,396 188,269 22.7511 90,175 86,342 10,195 186,713 22.5612 97,362 86,342 10,214 193,918 23.4313 67,749 86,342 10,130 164,221 19.8414 36,635 86,342 8,392 131,369 15.8715 7,052 86,342 7,395 100,788 12.1816 6,347 77,031 7,624 91,003 12.32Total 1,105,659 1,335,747 173,821 2,615,227 20.57
1 Year 1 mining costs also includes preproduction2. Includes stockpile re-handle
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 278/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 264
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
21.3.2 Mining Operating Costs
Mine operating costs were developed by SRK and based on the mine plan, equipment requirements,
and manpower requirements, parts of which have been presented in previous sections. The basis of
the operating costs is an owner operated mine. The mine operating costs include all the supplies,
parts, and labor costs associated with mine supervision, operation, and equipment maintenance
including rebuilds. Some pre-production development costs were included as part of the operating
costs. These costs may be treated as a capital cost during financial evaluation. Table 21.3.2.1
summarizes the total mine operating costs on a cost per tonne mined (from the pits), and total cost
per year basis.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 279/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 280/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 266
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Basis of Estimate
SRK estimated the required mining equipment fleets, required production operating hours, and
manpower to arrive at an estimate of the mining costs that the mining operations would incur. The
mining costs were developed from first principles. The mining operating costs are presented in the
following categories:
Production Drilling;
Production Blasting;
Production Loading;
Production Hauling;
Other Mine Operations (dozing, grading, dust suppression, other road maintenance
operations, etc.);
Support Equipment Operations (equipment fueling and maintenance, pit lighting, etc.);
Miscellaneous Operations (explosives storage operations, fleet dispatch operations, etc.);
Pit dewatering operations (pumps and piping);
Mine Engineering (mine technical personnel including technical consulting);
Mine Administration and Supervision (mine and maintenance supervision, etc.);
Mining Personnel Camp Costs; and
Freight (for equipment supplies and parts, excluding freight for fuel and explosives).
A maintenance cost was allocated to each category that requires equipment maintenance. The
operating costs are defined as starting in Year -2, and exclude any “pre-production operations”.
The mining costs are referenced as per tonne mined (waste and ore tonnes mined basis), and as per
ore tonne mined, (note the latter is not necessarily the same as per ore tonne processed in the same
year due to stockpile ore re-handling). By “per tonne mined” is meant as excavated from the open pits,
and does not include re-handled stockpile ore. This can lead to some distortion (increase) of the
“operating cost per tonne mined” (cost estimate) when significant amounts of stockpile material re-handling are carried out in a year, and relatively small amounts of pit mining occur in the same year.
Employee classifications, wages and burden benefits are based on information provided by
Sandspring. The costs for maintenance supplies and materials were based on estimates presented in
the current Infomine mining cost service publications.
It was assumed that the Toroparu Mine will not incur duties on imported equipment and supplies. No
account has been made for value added taxes (VAT), as these are normally accounted for in cash
flow modeling.
The mining operating cost estimates include the following parameters:
Diesel fuel cost of US$3.785/US gallon, or US$1.00/L (delivered to site); Average mining bench height of 10 m with ore mined in two 5 m flitches (lifts);
Average drilling penetration rate of 0.65 m/minute (instantaneous rate, no delays);
Blasting required for 88% of in-situ tonnage mined from the pit (12% free-digging);
Blasting powder factor of 0.233 kg/t (kg explosives per tonne of rock);
100% use of bulk emulsion explosives for blasting;
Averaged bulk emulsion cost of US$880/t (at site);
Average density for saprolite of 1.84 t/m3 and fresh rock 2.76 t/m3;
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 281/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 267
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Average moisture content for saprolite of 20% and fresh rock 6%;
Average swell factor of mined saprolite 20% and fresh rock 40%;
Typical mining operations support equipment utilization of 3,600 to 4,600 operating hours per
year (for track dozers, wheel dozers graders etc.);
2% of plant ore feed re-handled in primary crusher stockpile;
Estimated average tire lives of:Wheel loaders – 3,500 operating hours
Haul trucks – 4,500 operating hours
Motor graders – 3,000 operating hours, and
Other major mining equipment – 3,500 operating hours .
7% freight cost on mining operating and maintenance supplies;
Mining equipment rebuilds (overhauls) were included in the mining operating costs. These
were estimated based on a total of 75% of the original cost of the equipment unit over the
operating life of the machine, and scheduled as three overhauls during the operating life; and
No contingency is included in the mining operating cost estimates.
The mine operating cost estimate includes the following:
All mine labor, salaried and hourly;
Blasting supplies and loading of explosives;
Consumables, fuel, parts, tires, etc.;
An allowance for mine related overheads;
An allowance for general operating expenses for the mine offices and explosives magazines;
and
All mine functions to deliver material to the dumps, stockpile, and primary crusher.
Excluded from the mine operating cost estimate are the following:
Initial clearing of the pit area and initial mining haul roads (in mining pre-production capital); Post mining reclamation costs;
Process related or crushing costs;
General overheads outside of the mine; and
Taxes and property holding costs etc.
Mine Labor
The mine department will have salaried staff for mine administration, supervision of mine operations,
supervision of mine equipment maintenance, and for technical services (geology and mining
departments). Many of these positions will be a permanent day shift. Hourly employees will fill mining
production, mining support functions, and mining equipment maintenance positions.
The maximum mine administration and operations supervision staff will total 16 positions, and the
technical services staff total 13 positions. Total salaried staff was planned to reach a maximum of 38
positions. Salaried staff requirements were estimated for both expatriate and national employees.
The operations, mine equipment maintenance, and technical services will include:
Mine administration will include the mine manager and secretary. The mine manager will be
an expatriate position up to Year 7;
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 282/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 268
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Mine operations will include the mine general foreman, shift foremen, drill and blast foreman,
mine infrastructure foreman, mine supervisors, dispatch operator, cost controller, and training
supervisor;
Mine maintenance includes the maintenance foreman, senior maintenance supervisors, shift
foremen, and supervisors;
Technical services will include the technical services manager, secretary, and chief surveyor.The technical services manager will oversee the Mining and Geology departments, and will be
an expatriate position up to Year 7;
Mine geology includes the chief geologist, geologist, grade control engineer, and a
geotechnical engineer. The mine geologist will handle pit mapping, development drilling, and
other resource duties (such as local resource estimation and reconciliations). The grade
control engineer will supervise ore grade control in the mine. The geotechnical engineer will
be responsible for monitoring slope stability in the pits and waste dumps, as well as
monitoring material compaction and embankment stability at the TMA. The chief geologist will
be an expatriate position up to Year 7; and
Mine engineering includes the senior mining engineer, short- and long-term planners,
dispatch engineer (supervising mining equipment deployment), and drafts technicians.
Three mine production and maintenance hourly crews will be necessary (to be rotated on the two shift
system). Equipment operator labor positions were based on the number of mining equipment units
required, and on the assumption that some of the operators will be cross-trained. When some of the
operators are not required to be on one type of heavy equipment unit they will be able to operate
another. To maintain this situation it is planned for the mine department to have an equipment trainer
permanently on staff.
Operator positions were estimated for each year of operation. As mentioned, the number of
equipment operator labor positions was based on the number of mining equipment units required.
Required drilling, loading and hauling fleet equipment numbers were each rounded up to the nearestwhole unit required for a year, and each equipment unit was allocated three operators. This operator
estimate was adjusted up to allow for a 15% factor for vacation, sickness and absence (VSA). The
resulting operator estimate was then adjusted down (by 15%) to target meeting an average 85%
mechanical availability (MA) for the mining equipment units.
A mining equipment maintenance department will be staffed with mechanics, electricians, welders and
other maintenance personnel. Hourly maintenance man-hours were estimated as 70% of major
mining equipment man-hours required.
Mine total hourly labor requirements, including VSA and MA adjustments, are shown in Table
21.3.2.2. The hourly labor is divided into mine operations and mine maintenance. The peak number of
personnel occurs in Year 6, and the lowest number of personnel occurs in Years 15 and 16 when onlystockpile re-handling is taking place.
Annual salaries and annual (hourly paid) wages include burdens for the national staff personnel, and
the few expatriate staff planned.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 283/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 269
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 21.3.2.2: Mine Hour ly Labour Requi rements
Mine Hourly Labor - 2
- 1
1
2
3
4
5
6
7
8
9
1 0
1 1
1 2
1 3
1 4
1 5
1 6
BlastingBlaster 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Blasting laborer 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
Sub-Total Blasting 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
Equipment Ops
Drill operators 3 9 9 9 12 9 12 15 15 12 12 12 15 6 3
Loading operators 9 12 35 38 35 38 38 38 29 29 26 18 18 21 12 6 3 3
Truck drivers 12 38 135 152 167 182 179 199 176 188 147 135 135 138 73 41 6 6
Other mine equipment 32 50 50 50 50 50 50 59 59 59 59 59 59 59 59 47 18 18
Support equipment 7 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 3 3
Sub-Total Equip Ops 60 113 239 260 271 292 286 318 289 301 254 233 233 242 160 107 30 30
General Mine Ops
General mine Ops 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 3 3
Grade Control Tech 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Surveyor 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1
Rodman 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1
Sub-Total Eq Ops 18 18 19 19 19 19 19 19 19 19 19 19 19 19 19 19 6 6
Total Mine Ops 77 138 265 285 297 318 312 344 315 326 280 259 259 268 186 133 36 36
Maintenance
Truck fleet mechanics 26 44 89 96 100 107 105 116 106 110 94 86 86 90 61 42 12 12
Load/spprt fleet mech 13 22 44 48 50 53 52 58 53 55 47 43 43 45 30 21 6 6
Field maint mech 13 22 44 48 50 53 52 58 53 55 47 43 43 45 30 21 6 6
Sub-Total Maint 51 89 177 191 200 214 210 232 212 220 187 173 173 179 122 85 23 23
Total Hourly 129 227 442 477 497 532 522 577 527 547 467 432 432 447 307 218 60 60
Source: SRKIncluding VSA and MA adjustments
21.3.3 Process Operating Costs
Process operating costs are estimated at US$1,336 million, or US$10.51/t-milled over the LoM, as
summarized in Table 21.3.3.1.
Table 21.3.3.1: Plant Operating Costs (LoM)
Cost ItemLoM Cost
($000s)Unit Cost$/t-milled
Labor $74,486 0.59Electric Power $583,725 4.59Reagents $323,727 2.55Consumables $231,626 1.82
Maintenance $101,818 0.80Tailings $20,364 0.16CIL Operating Cost $1,335,747 10.51
Source: Tt, 2013 Addition differences due to rounding
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 284/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 270
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Labor
A small contingent of expatriate managers supplemented with trained nationals at supervisory
positions will be required for production and maintenance at the process facility and operation of the
tailings management facility. The operating and maintenance workforce will be Guyanese personnel.
Average all-in cost estimates for Guyanese labor were provided by Sandspring. During Pre-
Production, the process labor is estimated to be 91 personnel with an estimated annual cost of
US$2.30/t-milled. For Phase 1, the personnel requirement climbs to 136 persons with an estimated
annual labor cost of US$0.73/t-milled. For Phase 2, an additional 22 persons are added for a total of
158 persons with an estimated annual labor cost of US$0.87/t-milled.
Electric Power
Electric power will be generated on site to service mining, processing and all site service power
requirements using reciprocating engine generators burning intermediate fuel oil (IFO 180).
Power costs are estimated to be US$0.1769/kWh. The estimate is based upon a quoted fuel oil cost
of US$0.80/L ($0.1474/kWh) delivered and a 20% O&M cost of US$0.0294/kWh for operating the
generators.
Process power requirements are summarized in Table 21.3.3.2 for Pre-production, Phase 1 and
Phase 2 operations.
Table 21.3.3.2: Plant Power Requirements
Facility AreaPre-Production
@ 3.25k t/d(kWh/t)
Phase 1@ 15k t/d
(kWh/t)
Phase 2@ 22.5k t/d
(kWh/t)
Crushing 0.00 0.868 0.631HPGR/Milling 4.37 13.715 15.592Thickening 0.00 0.271 0.197Flotation 0.00 8.110 2.947CIP 8.42 1.658 2.411Elutions 1.11 0.218 0.301Tailings 3.83 1.652 2.406Reagents 0.08 0.124 0.090Water 0.42 0.553 0.402
Power Requirement 18.22 27.168 24.977
Source: Tt, 2013 Addition differences due to rounding
Reagents
Reagent consumption levels are based upon metallurgical test work conducted at SGS laboratories.
Unit costs for the major reagents consumed are based upon budgetary prices from suppliers or in-
house data. Consumption rates and estimated costs are presented by Phase in Tables 21.3.3.3
through 21.3.3.5.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 285/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 271
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 21.3.3.3: Reagent Consumption Rates and Cost – Preproduct ion
Reagent
Pre-ProductionSAP Leach
Cons.Rate
unit ReagentCost
Freigh t uni t Cost(US$/t)
1 Lime 1.33 kg/t $180 $19 per tonne $0.239
2 Sodium Cyanide 0.38 kg/t $3,000 $19 per tonne $1.1303 Sodium Hydroxide 0.10 kg/t $690 $19 per tonne $0.069
4 Flocculant 0.0 g/t $3,894 $19 per tonne $0.0005 Sodium Metabisulfite 1.06 kg/t $930 $219 per tonne $0.9866 Copper Sulfate 0.06 kg/t $3,880 $430 per tonne $0.2137 Carbon 40.0 g/t $3,810 $19 per tonne $0.152
8 Borax 0.15 kg/kg Cons $1,100 $410 per tonne $0.00029 Silica 0.15 kg/kg Cons $500 $174 per tonne $0.000110 Soda Ash 0.10 kg/kg Cons $550 $174 per tonne $0.000111 Potassium Nitrate 0.03 kg/kg Cons $1,650 $410 per tonne $0.0000
12 Diesel for Refinery/Carbon Kiln 182 L (000s) $0.82 per Liter $0.1261Total - - - - $2.790
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 286/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx
Table 21.3.3.4: Reagent Consumption Rates and Cost – Phase 1
Reagent
Phase 1
15k t/d Flotation w/Tailings Leach
Cons.Rate
unitReagent
Costunit
Cost(US$/t)
Cons.Rate
unitR
1 A208 30.00 g/t $2,820 $19 per tonne $0.085
2 MIBC 50.00 g/t $3,910 $19 per tonne $0.1963 PAX 50.00 g/t $2,760 $19 per tonne $0.138
4 CMC 20.00 g/t $4,750 $219 per tonne $0.095
5 Lime 0.50 kg/t $180 $19 per tonne $0.089 1.29 kg/t
6 Sodium Cyanide 0.23 kg/t $3,000 $19 per tonne $0.702 0.34 kg/t
7 Sodium Hydroxide 0.02 kg/t $690 $19 per tonne $0.012 0.10 kg/t
8 Flocculant 40.0 g/t $3,894 $19 per tonne $0.156 40.00 g/t
9 Sodium Metabisulfite 0.10 kg/t $930 $219 per tonne $0.092 0.92 kg/t
10 Copper Sulfate 0.00 kg/t $3,880 $430 per tonne $0.000 0.05 kg/t
11 Carbon 6.68 g/t $3,810 $19 per tonne $0.025 40.00 g/t
12 Nitric Acid 0.02 kg/t $410 $19 per tonne $0.007 0.10 kg/t
13 Borax 0.03 kg/kg Cons $1,100 $410 per tonne $0.0000 0.15 kg/kg Cons
14 Silica 0.03 kg/kg Cons $500 $174 per tonne $0.0000 0.15 kg/kg Cons
15 Soda Ash 0.02 kg/kg Cons $550 $174 per tonne $0.0000 0.10 kg/kg Cons
16 Potassium Nitrate 0.01 kg/kg Cons $1,650 $410 per tonne $0.0000 0.03 kg/kg Cons 17 Diesel for Refinery/Carbon Kiln 114 L (000s) $0.82 $0 per Liter $0.0171 68 L (000s)
Total - - - - $2.790 - -
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 287/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx
Table 21.3.3.5: Reagent Consumption Rates and Cost – Phase 2
Reagent
Phase 2
7.5k t/d Flotation w/Tailings Leach SAP Leach
Cons.Rate
unitReagent
Costunit
Cost(US/t)
Cons.Rate
unitReagent
Cost unit
Cost(US/t)
Cons.Rate
u
1 A208 30.00 g/t $2,820 $18.50 per tonne $0.085
2 MIBC 50.00 g/t $3,910 $18.50 per tonne $0.1963 PAX 50.00 g/t $2,760 $18.50 per tonne $0.138
4 CMC 20.00 g/t $4,750 $218.50 per tonne $0.095
5 Lime 0.50 kg/t $180 $18.50 per tonne $0.089 1.29 kg/t $180 $18.50 per tonne $0.232 0.84 k
6 Sodium Cyanide 0.23 kg/t $3,000 $18.50 per tonne $0.692 0.34 kg/t $3,000 $18.50 per tonne $1.025 0.55 k
7 Sodium Hydroxide 0.02 kg/t $690 $18.50 per tonne $0.012 0.10 kg/t $690 $18.50 per tonne $0.069 0.10 k
8 Flocculant 40.00 g/t $3,894 $18.50 per tonne $0.156 40.0 g/t $3,894 $18.50 per tonne $0.156 40.0 g
9 Sodium Metabisulfite 0.31 kg/t $930 $218.50 per tonne $0.288 0.92 kg/t $930 $218.50 per tonne $0.856 0.48 k
10 Copper Sulfate 0.00 kg/t $3,880 $429.50 per tonne $0.000 0.05 kg/t $3,880 $429.50 per tonne $0.186 0.03 k
11 Carbon 6.68 g/t $3,810 $18.50 per tonne $0.025 40.00 g/t $3,810 $18.50 per tonne $0.152 40.0 g
12 Nitric Acid 0.02 kg/t $410 $18.50 per tonne $0.007 0.10 kg/t $410 $18.50 per tonne $0.041 0.1 k
13 Borax 0.15 kg/kg Cons $1,100 $409.50 per tonne $0.0002 0.15 k
14 Silica 0.15 kg/kg Cons $500 $173.50 per tonne $0.0001 0.15 k
15 Soda Ash 0.10 kg/kg Cons $550 $173.50 per tonne $0.0001 0.10 k
16 Potassium Nitrate 0.03 kg/kg Cons $1,650 $409.50 per tonne $0.0000 0.03 k
17Diesel for Refinery/Carbon Kiln
13.88 L/t $0.82 $0.00 per Liter $0.0042 2.22 L/t $0.82 $0.00 per Liter $0.0249 166.28 L
Total - - - - $1.786 - - - - $2.742 - -
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 288/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 274
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Consumables
Consumption estimates for crusher liners, ball mill liners, and ball mill balls are based upon:
Abrasion indices
Power consumption
Metallurgical test data.
The cost estimate for consumables is presented by Phase in Tables 21.3.3.6 through 21.3.3.8.
Table 21.3.3.6: Consumables Cost Estimate – Pre-production
Consumables
Pre-Production
SAP LeachCons.
Rateunit
Cons.Cost
Freight unitCost
(US$/t)
1 Crusher Liners 0.000 kg/t $5,500 per tonne $0.0002 HPGR Rolls 0.000 kg/t $5,000 per tonne $0.000
3 Ball Mill Liner 1.00 allowance $100,000 per set $0.0844 Ball Mill Balls 0.276 kg/t $1,256 $174 per tonne $0.3945 Filtering Consumables 0.00 allowance $1,000 per tonne $0.000
Total - - - - $0.478
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 289/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx
Table 21.3.3.7: Consumables Cost Estimate – Phase 1
Phase 1
15k t/d Flotation w/Tailings Leach SA
Consumables Cons.Rate
unit Cons.Cost
Freight unit Cost(US$/t)
Cons.Rate
unit Cons.Cost
1 Crusher Liners - fixed perJacobs
kg/t fixed perJacobs
per tonne $0.027 0.000 kg/t $5,500
2 HPGR Rolls - fixed perJacobs
kg/t fixed perJacobs
15% per tonne $0.725 0.000 kg/t $5,000
3 Ball Mill Liner - fixed perJacobs
set/yr fixed perJacobs
15% per tonne $0.314 1.00 set/yr $100,000
4 Ball Mill Balls - fixed perJacobs
kg/t fixed perJacobs
15% per tonne $0.651 0.276 kg/t $1,256
5 Filtering Consumables - 0.10 allowance $1,000 per tonne $0.100 0.00 kg/t $1,000
Total - - - - - $1.818 - - -
Table 21.3.3.8: Consumables Cost Estimate – Phase 2
Consumables
Phase 2
7.5k t/d Flotation w/Tailings Leach SAP Leach
Cons.Rate
unit Cons.Cost
Freight unit Cost(US/t)
Cons.Rate
unit Cons.Cost
Freight unit Cost(US/t)
Cons.Rate
1 Crusher Liners fixed perJacobs
kg/t fixed perJacobs
per tonne $0.037 0.000 kg/t $5,500 per tonne $0.000 fixed peJacobs
2 HPGR Rolls fixed perJacobs
kg/t fixed perJacobs
15% per tonne $0.725 0.000 kg/t $5,000 per tonne $0.000 fixed peJacobs
3 Ball Mill Liner fixed perJacobs
set/yr fixed perJacobs
15% per set $0.514 1.00 set/yr $100,000 per set $1.370 fixed peJacobs
4 Ball Mill Balls fixed perJacobs
kg/t fixed perJacobs
15% per tonne $0.651 0.276 kg/t $1,256 $174 per tonne $0.394 fixed peJacobs
5 FilteringConsumables
0.10 allowance $1,000 per tonne $0.100 0.00 kg/t $1,000 per tonne $0.000 0.00
Total - - - - $2.027 - - - - $1.764 -
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 290/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 276
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
21.3.4 Off-Site Infrastructure Operating Cost
Port Facilities
The port facility operating costs were developed by FMG, Inc. and port sub-consultant Cargo
Velocity, LLC with consultation from Sandspring for local labor rates. Considered in the operatingcost estimate were office administrative staff, costs of administrative and office buildings, facility
security. Not considered in the operating cost estimate were annual debt payments for capital
expenditures, re-grading of aggregate yard surfacing and barge operating costs.
The port facility study considered three wharf concepts to observe the cost implications of differing
barge berthing options. All three wharf concepts facilitate the handling of the anticipated cargo types
and volume and apply the same backland infrastructure concept. For its lowest expected capital and
operating costs and lack of tidal range restrictions, a concrete ramp wharf concept is preferred and
considered in the port operating cost estimate.
The annual operating costs for the Pine Tree Landing port are anticipated to be US$1.25 million, and
include labor, equipment, fuel and camp costs. The port facility annual operating costs aresummarized in Table 21.3.4.1.
Table 21.3.4.1: Port Facility Operating Cost Estimate
Cost Item US$’000Labor 542EquipmentFuel
78487
Camp 145Total Annual Operating Costs 1,252Source: FMG, Inc., Cargo Velocity, Inc., Sandspring 2013
Access Road
Although Sandspring provides localized maintenance of the roadway from a man camp near the
Kumung River, overall operation and maintenance of the roadway is currently administered by the
GoG via a contract with ETK and a local contractor. After upgrade of the roadway, the GoG will bear
the full operating costs associated with the Toroparu Mine Road.
21.3.5 General & Admin istrative Costs
The G&A for the Toroparu Project was estimated for a typical year of operation. The total cost varies
between US$7 to US$11 million per year or US$1.37/t processed on average over LoM. A large
portion of the G&A cost is the labor component. The basis for the G&A personnel structure is the
experience gained by Sandspring’s management from other operating mines.
The management department consists of the general manager and the operations manager. The
finance/accounting department includes tax and cost accounting and IT services for the entire
organization. The supply chain department includes purchasing, contracts and warehouse functions.
The EHSS department is designed to have four functions: safety, occupational health,
safety/emergency response and security for the gold room and the main entrances to the site.
Because of its remote location, Toroparu will have on site an elaborate first aid/trauma center with
doctors and paramedics. The environmental department forms an integral part of the operation
although structurally belonging to administration.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 291/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 277
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
A portion of the G&A cost is the indirect cost component. It includes items such as safety supplies,
winter clothes, medical supplies, life insurance, general training, recreation and office supplies.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 292/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 278
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
22 Economic Analysis
22.1 Method of Evaluation
A discounted cash flow model was created to evaluate the Toroparu Project assuming the Project is100% equity financed. All revenues and costs are expressed in US dollars.
Mining cost estimates were provided by SRK and process costs were provided by Tt. Offsite
infrastructure costs were provided by FMG and Owner’s cost by Sandspring. Additional costs such
as refining, royalties and administrative costs are also subtracted from the revenue to calculate an
estimated cash operating margin. The evaluation considers the following terms for the calculation of
doré and copper concentrate net smelter return.
Doré
Payable Gold: 99.9%;
Dore Transportation & Insurance: US$2.45/Au-oz;
Refining Charge: US$0.65/Au-oz.
Copper Concentrate
The copper concentrate of the Toroparu project will have a copper grade of 21% and will yield
significant quantities of gold, which could result into a scenario that gold is the major value
contributor of these concentrates. It will also present some content of bismuth and selenium
contents, what will result in some penalties. The cash flow model assumes concentrates will be bulk
shipped in containers to Europe, on a weekly or bi-monthly basis. The following are the assumed net
smelter return terms.
Payable Copper: 96.5% of the agreed analytical copper content, subject to a minimum
deduction of 1 unit; Payable Gold: 97% of the agreed analytical gold content subject to a minimum deduction of
1 g/dmt shall be paid for at the mean of the morning/afternoon London gold fixings in USD$
Concentrate Treatment Charges: US$95/t-concentrate;
Copper Refining Charges: US$0.065/lb-Cu;
Predicted Penalties: US$5.44/lb-Cu, based on the following:
o Selenium: 200ppm free; excess to be penalized at US$ 1.50/100ppm Se;
o Bismuth: 200ppm free; excess to be penalized at US$ 2.75/100ppm Bi and dmt of
material;
Copper Insurance: 0.167% of gross revenue minus deducts;
Gold Refining Charges: US$6.50/Au-oz; Gold Insurance: 0.167% of gross revenue minus deducts
Additional handling charge of US$25.00/dmt of material due to the characteristics of the material for
special treatment, handling, storage etc. (for container shipments). This is in addition to the ocean
freight charges of US$100/dmt of concentrate.
An income tax rate of 30% is assumed based on estimates provided by Sandspring. The resulting
cash flow in each year of the Project life is discounted back to January of Year -3 to determine the
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 293/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 279
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
estimated discounted cash flow at a 5%, 8% and 10% discount rate. Using this same data, the
estimated internal rate of return and the undiscounted cash flow were also determined.
The Prefeasibility makes use of Proven and Probable Reserves only.
Results of the base case analysis indicate that the Toroparu Project has a potential after-tax internal
rate of return of 23.1% and a present value of approximately US$690.1 million, based on a 5%
discount rate.
The base case payback period is estimated at 2.6 years, including sustaining capital, from the start
of the production period (from the start of Year 1). Figure 22.1.1 presents the behavior of the
accumulated free cash flow.
22.2 Input Parameters
The proposed Project including the open pits, processing facility and on-site and off-site
infrastructure would be developed by Sandspring with assistance from EPCM contractors and
suppliers. The contractors would assist Sandspring in port development and the construction of the
camp, processing, HFO power generation facility, tailings management area and other infrastructure.
The open pits would be developed by Sandspring using its own labor force and equipment. The
open pits, processing facility and on-site and off-site infrastructure, logistics including concentrate
transportation to the port, port operation and barge loading would be operated and maintained by
Sandspring using its own labor force and equipment with the assistance of equipment maintenance
specialists; geotechnical consultants, an explosive supplier; and other specialists. The key criteria,
principal assumptions and input parameters used in the Base Case are shown in Table 22.2.1.
The major input parameters to the model include gold and copper prices, sustaining capital,
operating costs, mining rates, and estimated taxes and royalties. Additionally, several minor
assumptions throughout the model such as working capital, environmental accruals and depreciation
rates affect the estimated Project economics to a lesser degree.
SRK and Sandspring prepared a detailed financial model (the Financial Model) estimating cash flows
by year for the forecast mine life.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 294/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 280
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 22.2.1: Key Criteria, Princ ipal Assumpt ions and Input Parameters Used in the BaseCase
Item Key Criterion / Principal Assumptions
Open pit operationOpen pit mining
method
Conventional open pit mining
Saprolite is excavated, loaded and hauledFresh rock is drilled, blasted, loaded and hauled
Total tonnes mined 596 MtTotal mill feed minedand processed
127 Mt (total tonnage of saprolite & fresh rock mill feed)
Total waste mined 469 MtSaprolite miningand processingTotal tonnes ofsaprolite mill feed
A total of 5 Mt saprolite mill feed are mined
When mined Saprolite mining operations are completed in Year 11Saprolite mining rate 2.4 Mt of saprolite mined and processed in Years 1 and 2
The mining rate varies in Years 1 to 11 (up to 0.48 Mt/y)When processed Saprolite processed in Years -2 to 16,
Saprolite processingrate
A maximum of 3,250 t of saprolite processed per day during the pre-productionperiod.
Fresh rock mi ningand processing
122 Mt of fresh rock mill feed consisting of 67 Mt of ROM fresh rock mill feed and 55Mt of low grade stockpile material
Total tonnes of freshrock mill feed
Fresh rock mined in Years -2 to 14.
When mined Up to 15 kt/d combined mill feed and low grade stockpile material mined in Years 1 to3. Mill feed and low grade stockpile material mined at rates ranging from 19.5 kt/d to22.5 kt/d in Years 4 to 16. These rates do not include waste rock mining.
Mining rate Fresh rock ROM material would be processed in Years 1 to 16.Fresh rockprocessing rate
15,000 t/d processed in Years 1 to 3.
Fresh rockprocessing rate
22,500 t/d processed in Years 4 to 16.
Gold revenueGold price $1,400/ troy oz AuGold reporting todoréGold recovery fromsaprolite
Saprolite gold recovery ranges from 88.2% to 98%. This recovered gold would reportto the doré bar product.
Gold recovery fromFresh rock
Fresh rock fed to the flotation circuit will report 43.5% of gold to doré, throughleaching of rougher tails and leaching of a gravity concentrate, while the leachingcircuit recovers 95.9% of gold in the fresh rock.
Projected goldpayable
99.9% payable.
Projected doré bartransportation,insurance andrefining costs
$3.10/oz Au
Gold reporting tocopper concentrate
It is estimated that 42% of the gold recovered from the rougher flotation stage wouldreport to the copper concentrate.
Gold payable 97% payableProjected goldtransportation andsmelter
The costs are assigned to the copper concentrate
Projected goldrefining charge
$6.5/ troy oz Au
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 295/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 281
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Item Key Criterion / Principal Assumptions
Copper CreditProjected copper $3.25/lb CuProjected flotationCu recovery 91% CuProjected copper con
grade
21% Cu
Moisture content 8% moisturePayable deduction 3.5% of analytical copper contentProjected contransportation cost
$137.15/wet tonne of concentrate
Projected smeltertreatment charge
$95/dry tonne of concentrate
Projected copperrefining charge
$0.065/lb Cu
Royalties 8% gold royalty1.5% copper royalty
Operating costsMine saprolite $1.86/t-mined, including costs with rehandling and rebuilds.Processing $10.51/t processed (for processing, mill power and tailings disposal costs)
General andadministration cost $1.37/t processed
Escalation Costs and gold and copper prices are presented on real terms, based on Q1 2013
Depreciation method Straight line depreciation over five years
Projected corporatetax rate in Guyana
30%
The financial model assumes a three stage construction approach: the construction of small initial
startup for mining and processing of saprolite in Year -3 and the main grinding and floatation plant for
the fresh rock construction during Year -2 and -1. Commencement of processing is assumed at
January 1, Year -2 for the saprolite operation and at January 1, Year 1 for the fresh rock operation.
The processing rates for the stages described above are presented in Table 22.2.2.
Table 22.2.2: Project Stages
Description Value Units
Pre-Product ion Processing Rates
Saprolite Leach Daily Capacity 3,250 t/day
Fresh Rock Flotation Daily Capacity 0 t/day
Fresh Rock Leach Daily Capacity 0 t/day
Phase 1 Process ing Rates
Saprolite Leach Daily Capacity 1,500 t/day
Fresh Rock Flotation Daily Capacity 15,000 t/day
Fresh Rock Leach Daily Capacity 0 t/day
Phase 2 Process ing RatesSaprolite Leach Daily Capacity 175 t/day
Fresh Rock Flotation Daily Capacity 7,500 t/day
Fresh Rock Leach Daily Capacity 15,000 t/day
The model was also based on the following Project basic schedule:
Permitting and approvals: 1 year;
Construction period: 2 years;
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 296/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 282
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Production period: 16 years.
The model revenue stream is supported by the following production parameters.
Table 22.2.3 Production Parameters
Description Value uni tsWaste Mined 468,875 kt
RoM Material Mined/Milled 127,111 kt
Saprolite 5,022 kt
Fresh Rock Flotation 51,780 kt
Fresh Rock Leach 70,309 kt
RoM Average Au Grades
Saprolite 0.91 g/t
Fresh Rock Flotation 1.17 g/t
Fresh Rock Leach 0.89 g/t
RoM Average Cu Grades
Saprolite - %
Fresh Rock Flotation 0.18% %Fresh Rock Leach - %
Plant Metallurgical Recoveries
Au Recoveries
Saprolite Circuit 96.1% %
Fresh Rock Flotation 85.5% %
Fresh Rock Leach 95.9% %
Cu Recoveries
Saprolite Circuit 0.0% %
Fresh Rock Flotation 91.0% %
Fresh Rock Leach 0.0% %
Doré Gold Production
Au Metal Content 2,914 koz
Copper Concentrate Production 414 kt
Au Metal Content 820 koz
Cu Metal Content 191,781 klb
Total Production
Au Metal Content 3,735 koz
Cu Metal Content 191,781 klb
Payable Gold 3,707 koz
Payable Copper 182,649 klb
Market Assumption
Gold Price US$1,400 $/Au-ozCopper Price US$3.25 $/Cu-lb
Depreciation – Depreciation of US$820 million during the life of the operation includes initial capital
of US$501 million, sustaining capital of US$319 million, and previously invested capital of US$105
million. The inclusion of sunk capital is important as it affects taxes in the determination of cash flow
during the life of the mine.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 297/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 283
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Start-up – For the purpose of the model, the plant is estimated to commence the processing of
saprolite ore on January 1st of Year -2. Fresh rock starts to be processed on January 1st of Year 1.
Working capital – Working capital was included in the model. This estimate was considered as 20%
of all operating costs for each period.
Taxation – A 30%corporate tax rate was applied over the life of the Project.
Escalation – The components of the economic model were based on the following:
Base capital pricing for the Project is in Q1 2013 United States dollars, with no allowances
for inflation or escalation beyond that time;
Equipment quotes from vendors were obtained in Q4 2012; and
Operating costs were prepared in Q4 2012 terms.
All financial results are based in Q4 2012 and Q1 2013 dollars and no escalation has been assumed
for the metal prices or cost inputs.
22.3 Cashf low Forecasts and Annual Production ForecastsBased on the parameters aforementioned, Project evaluation resulting economics present an after-
tax net present value of US$690 million, at 5% discount rate, and an internal rate of return of
23.14%. Table 3.1 presents further details of the economic results. Payback from plant start of
operations (January of Year 1) is 2.6 years.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 298/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 284
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 22.3.1: Project Evaluation Economic Results
Description Value UnitsMarket Prices
Gold $1,400 /Au-ozCopper $3.25 /Cu-lb
Estimate of Cash Flow (all values inUS$000s)
Gross Income $/Au-ozPayable Gold (Doré+Concentrate) $5,190,263 $1,400.00Payable Copper $593,609 $160Gross Income $5,783,872
$/Au-ozTreatment Charges ($39,353) ($10.61)Refining Charges ($18,937) ($5.11)Predicted Penalties ($2,253) ($0.61)Freight Insurance Cost ($71,641) ($19.32)Gross Revenue $5,651,687
$/Au-oz
Guyana Au Royalty ($413,937) ($111.65)Guyana Cu Royalty ($7,162) ($1.93)One Time Royalty to Surface Owner ($20,000) ($5.39)Net Revenue $5,210,588Operating Costs $/Au-ozMining Cost ($1,105,659) ($298.24)Processing Cost ($1,335,747) ($360.30)Site G&A Cost ($173,821) ($46.89)Total Operating ($2,615,227)$/t-ore ($20.57)Cash Cost ($/Au-oz) ($700)Operating Margin (EBITDA) $2,595,362Initial Capital ($501,192)
Total Capital ($820,651)Income Tax ($506,310)Cash Flow Available for Debt Service $1,268,400Pre-Tax IRR 27.19%Pre-Tax Present Value 0% $1,774,710Pre-Tax Present Value 5% $991,516Pre-Tax Present Value 8% $702,064
After-Tax IRR 23.14% After-Tax Present Value 5% $690,869 After-Tax Present Value 8% $476,171
Af ter-Tax Present Value 10% $367,345
The economic modeling resulted in a life of mine cash cost of US$700/Au-oz, as presented in thetable below.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 299/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 285
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 22.3.2: Summary of LoM Production and Cashflow
Type LoM ($000s) US$/Au-oz
Direct Cash Costs 2,143,915 578
Mining Cost 1,105,659 298
Processing Cost 1,335,747 360
Site G&A Cost 173,821 47Freight Cost 61,753 17
Treatment Charges 39,353 11
Refining Charges 18,937 5
Predicted Penalties 2,253 1
By-Product Credit (593,609) (160)
Indirect Cash Costs 450,986 122
Royalties 441,099 119
Freight Insurance Cost 9,887 3
Total Cash Cost 2,594,901 700
Table 22.3.3 shows annual production and revenue forecasts for the life of the project. All productionforecasts, ore grades, plant recoveries and other productivity measures were developed by
independent consultants.
Table 22.3.3 Project LoM Annual Production and Revenues
PeriodRoM
(kt)Waste
(kt)Ore Milled
(kt)Doré Gold
(koz)Cu Con. Gold
(koz)Cu Con. Copper
(klb)Revenue
(US$000s)
-3 0 0 0 0 0 0 (151,850)
-2 1,566 698 1,186 47 0 0 (164,030)
-1 5,863 7,137 1,186 36 0 0 (148,536)
1 13,623 26,375 6,023 146 129 29,519 250,614
2 8,000 31,999 6,023 113 99 25,293 165,209
3 8,164 32,132 5,992 105 91 22,164 76,875
4 7,981 31,371 8,276 263 36 8,484 151,754
5 8,962 31,907 8,276 197 60 11,051 110,645
6 5,899 41,855 8,276 172 37 9,116 38,237
7 8,194 44,385 8,276 194 60 10,574 84,655
8 19,695 37,200 8,276 290 64 7,853 176,039
9 1,600 45,490 8,276 152 30 8,503 34,918
10 11,711 33,335 8,276 232 38 8,666 131,434
11 12,725 37,428 8,276 286 49 8,198 175,775
12 2,255 48,125 8,276 152 19 8,239 31,548
13 4,499 17,301 8,276 149 36 10,149 73,972
14 6,374 2,139 8,276 189 36 8,236 126,982
15 0 0 8,276 101 18 8,217 57,668
16 0 0 7,385 89 17 7,519 28,29117 0 0 0 0 0 0 18,201
Total 127,111 468,875 127,111 2,914 820 191,781 1,268,400
22.4 Sensit ivity Analysis
A sensitivity analysis for key operating and economic parameters is shown in Tables 22.4.1 through
22.4.3 and Figures 1.14.1 and 22.4.1. The Project is most sensitive to gold price. Because the
change in NPV is greatest with gold price change, it is this parameter that most significantly affects
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 300/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 286
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
the economics of the Project. Additionally, sensitivity to discount rate has been simulated and is
presented in Figure 22.4.2.
Table 22.4.1: Sensitivity to Capital Costs
Capital Costs Sensitiv ity Base 80% 90% 100% 110% 120%
After-Tax NPV 5% 690,869 787,312 739,104 690,869 642,634 593,883 After-Tax NPV 8% 476,171 567,303 521,756 476,171 430,586 384,289
After-Tax NPV 10% 367,345 455,516 411,453 367,345 323,238 278,323
IRR 23.14% 29.07% 25.86% 23.14% 20.80% 18.72%
Table 22.4.2: Sensitivity to Operating Costs
Operating Costs Sensitiv ity Base 80% 90% 100% 110% 120%
After-Tax NPV 5% 690,869 922,918 806,893 690,869 574,844 458,260
After-Tax NPV 8% 476,171 658,171 567,171 476,171 385,171 293,426
After-Tax NPV 10% 367,345 523,935 445,640 367,345 289,051 209,928
IRR 23.14% 27.62% 25.43% 23.14% 20.73% 18.10%
Table 22.4.3: Sensitivi ty to Metal Prices
Revenue Sensi tivit y Base 80% 90% 100% 110% 120%
After-Tax NPV 5% 690,869 203,584 448,392 690,869 932,182 1,172,911
After-Tax NPV 8% 476,171 87,525 283,383 476,171 667,357 857,707
After-Tax NPV 10% 367,345 29,065 199,899 367,345 532,976 697,634
IRR 23.14% 11.18% 17.57% 23.14% 28.13% 32.70%
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 301/340
(160)
(120)
(80)
(40)
-
40
80
120
160
200
240
280
320
360
400
(560,000)
(420,000)
(280,000)
(140,000)
-
140,000
280,000
420,000
560,000
700,000
840,000
980,000
1,120,000
1,260,000
1,400,000
Cumulative Free Cash and NPVs
Cumulative FCF
Project Capital
Total Payable Gold
Toroparu Gold Project,
Guyana
Figure 22.1.1
Cumulative Cash FlowSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 302/340
0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
30.00%
35.00%
80% 90% 100% 110% 120%
IRR Sensivity (%)
Capital Costs
Operating Costs
Revenue
Toroparu Gold Project,
Guyana
Figure 22.4.1
IRR Sensiti vitySource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 303/340
(200,000)
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
0 %
1 %
2 %
3 %
4 %
5 %
6 %
7 %
8 %
9 %
1 0 %
1 1 %
1 2 %
1 3 %
1 4 %
1 5 %
1 6 %
1 7 %
1 8 %
1 9 %
2 0 %
2 1 %
2 2 %
2 3 %
2 4 %
2 5 %
2 6 %
2 7 %
2 8 %
2 9 %
3 0 %
NPV vs Discount Rate
NPV
Toroparu Gold Project,
Guyana
Figure 22.4.2
NPV sensit ivity to Discoun t RateSource: SRK, 2013
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 304/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 290
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
23 Adjacent PropertiesSandspring is not aware of any significant properties situated immediately adjacent to Toroparu.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 305/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 291
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
24 Other Relevant Data and InformationThere is no other additional information or explanation necessary to make the technical report
understandable and not misleading.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 306/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 292
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
25 Interpretation and Conclusions
25.1 Geology and Resources
The geology of the Toroparu gold-copper deposit is defined primarily from drill core. The depositgeology is a network of veinlets and fractures hosting quartz and calcite and minor amounts of pyrite
and chalcopyrite that contain the gold and copper mineralization, hosted in a WNW to E-W structural
zone that forms the deposit. The Toroparu deposit is sufficiently drilled for feasibility level study.
Drilling and sampling procedures, analytical procedures, and QA/QC programs and results establish
the drillhole database that supports mineral resource estimation as credible, verifiable, and
developed by appropriate common industry best practices.
Since the 2012 PEA resource estimation (P&E, 2012), the drillhole database has been augmented
with an additional 214 drillholes for 56,259 m, or an increase of 38% in total meters of drilling. A total
of 48 of the holes, for 12,163 m, in both the Main Zone and the Southeast Zone, were for targeted
infill drilling designed to both increase confidence in the estimation and to provide a better definitionof mineralized zones. The majority of the remaining 166 holes were for delineation drilling. The
additional sampling was effective in upgrading confidence in the resource estimate. Additional
information has allowed the development of internal controls delineating mineralized versus non-
mineralized areas of the overall deposit.
Mineral resources have been updated for this prefeasibility level technical report. The Toroparu
deposit contains approximately 240.2 Mt of Measured and Indicated mineral resources grading 0.89
g/t Au and 0.084% Cu for 6.894 Moz of contained gold and 444 Mlb of contained copper, at a 0.30
g/t Au cut-off grade, in all mineralized zones. In addition there is an additional 129.5 Mt of Inferred
mineral resources grading 0.74 g/t Au and 0.042% Cu, for 3.090 Moz of contained gold and 120 Mlb
of contained copper, at the same 0.30 g/t Au cut-off grade.Within the prefeasibility design pit shape, there is 97% Measured and Indicated resources.
Therefore, additional targeted drilling to convert Inferred resource’s to Measured and Indicated is
possible, but in SRK’s opinion not necessary to advance the Project to full feasibility level study. The
resource estimate, therefore, is deemed sufficient for feasibility level.
Additional step-out definition drilling can be done to explore the eastern extension of mineralization in
the main pit area; a region of shallow placer working that is low in topography and partially flooded.
The potential exits in this area for expanding the pit to the east with incremental additions of low
grade material. The Southeast Zone is open at depth and to the southeast, and is a target for
exploration drilling – access is difficult due to the proximity of the river. These areas of additional
exploration drilling are warranted, at some point in time, but are not in SRK’s opinion necessary toadvance the Project to full feasibility level study.
25.2 Mining and Reserves
Pit Slope Geotechnical
The PFS pit slope design for the Toroparu Project was based on the currently available geotechnical
data and the geological model. This design mainly focuses on the proposed open pit in the main
deposit area. The stability analyses confirm that the recommended pit slope angles are reasonable
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 307/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 293
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
and appropriate. This design has a number of operational constraints including requirements for
careful blasting and for effective management of surface run-off water and seepage. Extensive
monitoring and ongoing commitment to data collection are also recommended throughout the
operational life of the mine.
The 2010 field program did not cover the SE Pit area. Additional data collection and further studieswill be required to carry the Project to a feasibility level of design, however, the geologic conditions
are similar and this pit is a likely proxy for the Toroparu main deposit. The SE Pit contributes 6.8% to
the Proven and Probable reserves and it is commissioned after the 4th year of full production.
Mining
The PFS mining studies were based on multiple trade-off studies to arrive at an optimum production
schedule for the Project. Some refinements with respect to the pit designs, mine production
schedule, and mine equipment selections can be made at a feasibility level study. The current PFS
mining studies exceed the requirements of a prefeasibility level study.
25.3 Metallurgy, Processing and RecoveriesSandspring conducted several metallurgical testwork programs between 2009 and 2013 which
provided the basis for process design to prefeasibility level.
Sandspring has provided a list of drillholes and intervals of samples collected for metallurgical
testwork performed between 2011 and 2013, along with a 3-D plot showing the location of the
samples within the deposit. Assays of drill core intervals show that low, medium and high grade
portions of the ore body are represented in the sample set. The samples appear to be spread
geographically across the ore body. Although more sampling is recommended to cover variability
metallurgical testwork to support a feasibility study, the samples appear to be representative and
sufficient for the Prefeasibility study.
Testwork showed that multiple processes are warranted to provide economic benefit to different ore
variabilities in the deposit. Metallurgical testwork and financial analysis tradeoffs were performed to
show that processing the deposit with both flotation and cyanide leaching, depending on Cu content,
would provide economic benefit due to the recovery of a marketable Cu concentrate.
Ores containing a higher Cu content responded more economically to gravity concentration followed
by Cu flotation and cyanide leaching of the cleaner flotation tailings. Overall recoveries of this
process are expected to be 91% for Cu and 88% for Au.
Ores with low Cu content responded more economically to gravity concentration followed by cyanide
leaching of the gravity tailings. Overall recoveries of this process are expected to be 96% for Au.
Gold bearing saprolite ores showed no benefit from gravity concentration but did respond best to
whole ore cyanide leaching. Recoveries of this process ranged between 88% to 98% depending on
the retention time in the leach circuit, which varies throughout the LoM.
Process facilities were designed to achieve the stated recoveries based on test results and standard
engineering design practices to a prefeasibility level. Process facilities include comminution circuits
consisting of primary/secondary crushing circuit feeding into one of two HPGR/ball mill grinding
circuits. Each circuit is followed by Cu flotation and/or cyanide leaching. Tailings from the process
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 308/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 294
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
facility will be treated through a cyanide destruction circuit prior to discharge into the TMA facility.
Products from the process facility include gold bearing copper concentrate and gold doré.
25.4 Infrastructure
On-Site Infrastructure
On-site infrastructure was identified and designed sufficient to support the PFS report. Internal
service roads, bridge crossings, and operational support facilities were developed to a point sufficient
for costing and use in the economic model. Power is generated to support the operation. Water is
sourced from the Puruni River and Wyanmu River. An extensive water management plan was
performed to assure year round operation.
Off-Site Infrastructure
Considering the relatively remote location of the Toroparu Mine, off-site infrastructure will play a key
role in the operation and success of the Project. The presence of an existing roadway from the
Mazaruni River to the mine is advantageous, and upgrades to the roadway will ensure safe, reliable
transport of cargo to and from the mine. Overall operation and maintenance of the roadway is
currently administered by the GoG via a contract with a local contractor. After upgrade of the
roadway, the GoG will bear the full operating costs associated with the Toroparu Mine Road.
Construction of the port facility at Pine Tree Landing will create a secure shipping point for mine
equipment, bulk mine supplies and concentrate, and will serve as a base camp for mine supply chain
transport vehicles.
25.5 Project Implementation
The Project schedule would be an estimated duration of 36 months from the award of the EPCM
contract for detailed engineering, to the mechanical completion of the processing plant, through
commissioning activities and into production.
The schedule critical path, which determines the overall Project duration as determined by the
shortest logical chain of related events, must be followed to ensure completion of the Project by the
scheduled date. For the process plant construction of Toroparu Gold Project, it is estimated that the
critical path will run through the substation installation, electrical procurement, and electrical design.
Critical milestones included Sandspring’s ability to obtain Project financing, award of EPCM contract,
as well as the associated pre-development work in the open pit and tailings area.
Project approval and the beginning of pre-development construction activities are scheduled to occur
right away in order to maximize the usable construction seasons. It is imperative that road access
into the various parts of the site be completed early in order to facilitate the transport of constructionmaterials and equipment to their work areas.
Three engineering disciplines must be started right away. The first is geotechnical in order to confirm
site conditions and provide the civil engineers with necessary information for the early detailed
engineering. The second and third are the process and mechanical in order to facilitate plant design
for the early ordering of long lead time equipment.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 309/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 295
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
There are a number of pieces of equipment in this Project which typically have long delivery times
associated with them, which will need to be addressed as priorities. The longest delivery items
should get priority for placing purchase orders to support the construction schedule.
This Project schedule is driven by construction, and construction in turn is driven by site conditions.
There are three key activities which must start on schedule and which will dictate the success of
bringing this Project in on time. These activities are:
Primary power;
Process plant design;
Site infrastructure; and
Roads.
25.6 Environmental Studies and Permitting
The Project area has been historically impacted by mining activities, logging, and hunting.
With only a few exceptions, species classified as rare, threatened or endangered have not beenobserved in the Project area.
There are no formal or established communities in the immediate vicinity of the site. The Project is
not expected to generate many direct socio-economic impacts. A Social Management Plan has been
proposed to mitigate the socio-cultural impacts identified in the ESIA.
No indigenous hunting activity or cultural resources were identified within the proposed mining area.
Results of the geochemical testing of the waste rock showed that the waste rock lithologies and LGO
samples contained very low sulfide-sulfur concentrations, indicating low risk of PAG, except for the
saprolite. The saprolite and transition zone samples contained very low NP, whereas the waste rock
and LGO had NP related to reactive carbonate minerals. The saprolite samples were classifiedprimarily as acid-generating and PAG, whereas the other waste rock and LGO samples were
classified as non-PAG.
The tailings samples contained low to negligible sulfide-sulfur concentrations and were classified as
non-PAG. The majority of the NP of the tailings was associated with the reactive carbonate minerals
and/or lime added during the metallurgical testing. The saprolite tailings contained little to no reactive
carbonate minerals, and thus the NP present in the saprolite tailings was related to the lime added
during the metallurgical process.
Leachate testing indicated that the waste rock may develop alkaline drainage with the possibility of
elevated concentrations of aluminum, selenium, chromium and, to a lesser extent, copper and
phosphorus. The tailings could develop alkaline drainage with the possibility of elevatedconcentrations of aluminum, selenium, chromium, arsenic, cobalt, copper, iron, molybdenum, WAD
cyanide and sulfate. The TMA design assumes that the natural low permeability of the surficial soils,
and the lower concentrations of elements in the TMA pond due to attenuation from natural
degradation, settling, and mixing with precipitation, which averages about 2.6 m annually, will reduce
concentrations in any TMA discharge effluent to the aquatic receiving environment. Additional
analysis (i.e., predictive water quality modeling) will be needed in a later phase to verify this
assumption.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 310/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 296
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The Project will develop and implement an Environmental Management Plan.
An ESIA was prepared and submitted to the Guyana EPA, which subsequently issued an
environmental permit for mining and processing. The final mining permit will be required prior to
commencing full-scale operations.
25.7 Economic Analysis
A discounted cash flow model was created to evaluate the Toroparu Project assuming the Project is
100% equity financed. All revenues and costs are expressed in US dollars.
An income tax rate of 30% has assumed. The resulting cash flow in each year of the Project life was
discounted back to January of Year -3 to determine the estimated discounted cash flow. Using this
same data, the estimated internal rate of return and the undiscounted cash flow were also
determined.
Using a gold price of US$1,400/oz and a copper price of US$3.25/lb, results of the base case
analysis indicate that the Toroparu Project has a potential after-tax internal rate of return of 23% and
a present value of approximately US$690 million, based on a 5% discount rate.
The base case payback period is estimated at 2.6 years, including sustaining capital, from the start
of the production period (from the start of Year 1).
These positive results indicate that the Project should be advanced to a Feasibility Study.
25.8 Risks and Uncertainties
Mining
The following potential risk aspects should be further assessed during a feasibility study for the
Project:
Determination of peak water inflows to the pit at various stages of mine development to
ensure adequate pit dewatering capacity exists to achieve close to continuous operations;
Assessment of appropriate pit development methods (including drainage) and mining fleet
equipment selection for efficient mining of the significant thicknesses of saprolite material (up
to approximately 75 m); and
Detailed mine production scheduling to ensure continuous ore exposure in the pits,
particularly during periods of low ore stockpile inventories.
Mineral Processing
A full risk assessment of the transportation of reagents and consumables to site and concentrates to
the port facility should be conducted to determine any logistics issues given the plant site location.
Whilst there is no shortage of water on-site, a clean source of fresh water has yet to be finalized, and
should be identified early in the next phase of the Project.
On-site Infrastructure Risks
The site locations for plant facilities and man camp do not have condemnation drilling. There is a
potential that resource could be found under these locations that could potentially necessitate
relocation of this infrastructure.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 311/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 297
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
The cost estimate has been developed based on maximizing the use of local borrow sources and
reduced construction material haul distances to help lower the construction costs. Increase of
material haul distances will negatively impact the construction costs.
Tailings Management Area
The following potential risk aspects exist for the TMA:
The key risk at the tailings storage area is the absence of ground information. The designs
presented above are only conceptual until it is shown the ground can support the proposed
dam structures. It has been assumed that the site presents a thick horizon of low
permeability residual soils, which is key to minimize seepage into the groundwater regime
and to eliminate the need of a geomembrane liner along the pond basin;
The climatic information at the site is sparse so the sizing of diversion ditches, spillways, and
freeboard are rough estimates at this time. Climatic data needs to be collected now and
throughout the life of the Project; and
A key assumption is that the surface soils within the tailings pond will form an effective
barrier to contaminants exiting the impoundment area as was experienced at the second
Omai tailings impoundment. This cannot be confirmed without a ground investigation
program at the tailings area.
Off-site Infrastructure
The use of trained, reliable local labor has been assumed in developing the roadway construction
costs and estimated schedule of work. Therefore, the unavailability of trained, reliable labor would
negatively impact construction costs and may cause delays in completion of the upgrades.
Also, the estimated roadway upgrade cost was based on accessible local aggregate surfacing
sources which have been preliminarily identified by Sandspring. The logistics to access, process and
transport these materials may vary somewhat from those assumed in the development of the costestimate. To hedge against this variability, a 20% contingency was assigned to this item in the
upgrade capital costs.
Overall operation and maintenance of the roadway is currently administered by the Government of
Guyana (GoG) via a contract with a location contractor, and the GoG will bear the full operating costs
associated with the Toroparu Mine Road after upgrade of the roadway. If the GoG should
discontinue its participation in the roadway, Sandspring will be required to facilitate some
maintenance of the portion of the roadway necessary for operation of the Toroparu Mine.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 312/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 298
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
26 Recommendations
26.1 Recommended Work Programs and Costs
Phase I is the fieldwork and testwork necessary in order to complete a feasibility study, with Phase IIbeing the actual feasibility study having all fieldwork and testwork available.
26.1.1 Phase I
Open Pit Geotechnical/Hydrogeological Programs
The PFS pit slope design for the Toroparu Project was based on the currently available geotechnical
data and the geological model, which mainly focused on the proposed open pit in the main deposit
area. The 2010 field program did not cover the SE Pit area, and additional data collection is
recommended. Recommendations for future pit geotechnical/hydrogeological programs to carry the
Project to feasibility are below:
Complete additional geotechnical investigation at the proposed satellite pit; and
Evaluate the hydrogeological characteristics and pit dewatering requirements (shallow well
pumping tests for dewatering design).
The costs for the above pit geotechnical/hydrogeological programs are estimated below:
Oriented core drilling and testing at South-East deposit (3 holes, 200 m deep), with
mobilization/demobilization, special equipment, materials and testing: US$170,000; and
Engineering time and travel charges for field supervision and senior supervision site visit:
US$100,000.
The total cost for pit geotechnical/hydrogeological programs is in the order of US$270,000.
Drilling/Geology/Resources:
There is no need for additional in-fill or step-out drilling for Phase I recommended work to advance
the Project to completion of feasibility level study.
Mining
No mining related fieldwork or testwork will be required in advance of a feasibility study.
Condemnation Drilling
Sandspring intends to perform a planned condemnation drilling program for the Toroparu Project
site, to include sites for the waste dumps, stockpile, process plant, site infrastructure, tailings
management area, mine village, etc. The two main site locations would be the mine facilities area(dumps, stockpile, plant, etc.) and the tailings management area (approximately 8 km to the
northeast). It is proposed to dill a total of 16,000 m of drilling consisting of drillhole lines spaced
either 500 m or 1,000 m apart, with drillholes placed at 100 m intervals along these lines. Drillholes
would be drilled at 45 degree inclinations to a depth of 70 m. An allowance for an additional 2,000 m
of drilling has been included to further investigate areas where drill results indicate mineralization.
The total drilling program may take seven months.
The estimated costs for the condemnation drilling program are shown in Table 26.1.1.1.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 313/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 299
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Table 26.1.1.1: Condemnation Drilling Program
Condemnation Drilling RAB RigDrillingLength
(m)No. of
Samples
Cost per Unit
($/unit)Total Costs
(US$s)
RAB Drill Costs 16,000 $30/m $480,000 Laboratory Costs (RAB Samples) 900 $24/sample $138,240 Drill Fuel 96,000 Road and Pad Preparation
Fuel, Oil, Lubricants 80,00 Maintenance and Spare Parts 179,200
Technical Personnel 89,600 Local Team Wages (4 RAB) 118,400 Sub-totals 16,000 900 $1,181,440
Additional Investigative Drilling 2,000 150 $148,560Totals 18,000 1,050 $1,330,000
Source: Sandspring, 2013Costs exclude existing camp operating costs, and transport costs to and from site of personnel and materials.
Metallurgy and Processing
Testwork on the ACO and LCO composites has shown that a significant amount of copper is loaded
onto the carbon following cyanide leaching. To limit the amount of copper loading on the carbon, the
initial cyanide concentration may need to be increased. The higher cyanide concentration will likely
increase the extraction of copper and we recommend further optimization testing to further define the
design parameters. It is also recommended that a Gravity Recoverable Gold (GRG) test be
conducted to further define the effect of grind size on the recovery of gold. Flotation testwork
conducted during this program has focused on evaluating the effect of grind size on recovery, but
additional study will be required to finalize a flotation circuit flowsheet. The results from the locked
cycle test of the ACO Master Composite indicated that there is a build-up of non-sulfide gangue in
the cleaning circuit. It is recommended that further flotation testwork be conducted to betterunderstand the effect of cleaner circuit flowsheet and use of gangue depressant, CMC, and other
reagents and flotation flowsheets to potentially improve the process.
We recommend additional variability testing with regard to gravity separation, copper flotation and
cyanide leaching on the LCO composite. The testing should identify the gold response in variation to
head grade. .
A pilot scale HPGR test, in which 2 tonnes of material is tested, is recommended to properly size the
HPGR unit, as the relevant testwork to date only provides preliminary sizing information on a scoping
level. This should be performed in conjunction with variability comminution testing to provide better
selection of ball mills.
Due to the number of thickeners present in the proposed flowsheet, additional thickening tests are
recommended to properly size the thickeners. These tests should evaluate the following:
ACO rougher flotation tailings;
A mixture of the CIP tailings comprised of saprolite and ACO cleaner flotation tailings;
LCO whole ore material; and
A mixture of the CIP tailings comprised of LCO material and ACO cleaner flotation tailings.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 314/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 300
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
In the event that variability gravity/float/and leach testing of the ACO or LCO material indicates an
alternative process flowsheet, then thickening tests should be expanded to reflect such a change.
This is especially relevant if an LCO cleaner flotation process is considered to better define the
impact of finer particles due to the regrind circuit which will impact on settling behavior.
If sufficient sample is produced, thickening and filtration testing of the copper concentrate should beperformed as selection and sizing of concentrate dewatering equipment is currently assumed due to
the absence of any related testwork.
Additional CND testing should be performed to confirm earlier findings. In addition, should any of the
variability testing of the ACO or LCO material yield a flowsheet significantly different than what is
currently proposed then CND testing should be expanded to included such changes.
Along with the recommend testwork necessary for the feasibility study, Sandspring may consider
investigating alternative processes methods such as SART (Sulfidization Acidification Recycle
Thickening).
It is estimated that the costs of this testwork is US$225,000. This excludes the costs of engineering
oversight and the costs of procurement of the samples themselves.
On-site Infrastructure
Tt recommends the following work to progress the Project to the next level:
Perform condemnation drilling and testing at the proposed plant site and man camp site;
Perform a geotechnical site investigation that includes test pits, drillholes and seismic
refraction surveys to support foundation design and engineering;
Perform a feasibility study design on the on-site infrastructure;
Confirm water supply source, quality and quantity requirements; and
Confirm wastewater treatment, discharge point, quality and quantity requirements.
Geotechnical Site Investigation
Tt recommends a geotechnical field investigation at the Toroparu Gold Project to supplement
previous investigation testing programs conducted at the site and to provide data to support a
feasibility study. The investigation program should include drilling of eight (8) boreholes and
excavating six test pits within the footprints of the proposed diversion structures, saddle dikes, man
camp and process facilities. The drilling and sampling program is aimed at characterizing the
subsurface conditions at the site as part of the feasibility design of the facilities.
Boreholes
The drilling program consists of a total of eight boreholes drilled to depths up to 50 m below ground
surface. Drilling can be stopped 3 m past the surface of competent bedrock if less than 50 m.
Surface drilling to the rock should be conducted using auger techniques that allows the ability of
performing Standard Penetration Testing, and collect disturbed and undisturbed samples. Sonic
drilling techniques are likely to fracture and/or crush coarse grained formations due to the vibratory
action at the drill bit and are therefore not acceptable for obtaining representative subsurface
samples for geotechnical characterization.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 315/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 301
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Test Pits
The test pit program should consist of a series of test pits to be trenched within the proposed
excavation areas for the process facilities, man camp, diversion structures and saddle dams. Test
pits depths should range 3 to 6 m below ground surface based on the ability of the available
equipment.
Sampling Requirements
The following sampling techniques are recommended for the Project:
SPT Split Barrel Sampling (ASTM D1586);
Undisturbed Samples with Shelby Tubes; and
Disturbed Samples in 5 gallon buckets.
Laboratory and Field Tests
Tt recommends the following laboratory and field tests. All testing should be performed according to
the appropriate ASTM Standard.
Modified proctor test;
Full gradation;
-200 sieve wash;
Atterberg limits;
Moisture content/in-place density;
Unconfined compressive strength of rock;
Swell/consolidation test;
Direct shear test (3 point); and
pH, chlorides and sulfates Test.
The estimated cost for performing the above mentioned work ranges between US$75,000 toUS$100,000.
Tailings Management Area
Recommended fieldwork and testwork for feasibility design of the Tailings Management Area
includes the following:
Geotechnical field investigation program including:
o Local mapping;
o Drilling, coring and sampling of foundation materials;
o In situ testing and piezometer installation;
o
Test pit program with excavator for review of shallow foundation soils and sampling;o Site wide mapping program to search for filter materials, and
o Laboratory testing.
Estimated costs (including a 25% contingency):
o Drilling contractor costs: US$ 200,000 to US$ 250,000);
o Field supervision and travel fees: US$ 215,000;
o Laboratory fess: US$ 15,000; and
o Costs for construction of accesses not included and to be assumed by Sandspring.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 316/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 302
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Off-site Infrastructure
Logistics Phase I – US$30,000:
o Verification of road maintenance agreement with GoG;
o Further definition of fuel supply logistics. Possible Trade-off Study of turnkey supply to
mine vs. SSP transport from port bulk storage; ando Verify availability and cost of port aggregate surfacing.
Pre-Design Engineering Phase I – US$85,000
o Further proving of aggregate surfacing sources;
o Further definition of tidal fluctuations;
o Bathymetric survey of Pine Tree Landing area; and
o Bridge and culvert hydrologic review.
Site Environmental and Project Closure
The geochemistry program should be advanced to a more detailed program that will include
predictions of water quality associated with the mining wastes run-off and discharges. Water quality
management strategies are needed for the tailings pond. Further static and kinetic testing isrecommended.
It is recommended that monitoring at the weather station be re-established, and that the data
collected include evaporation information as well as precipitation data recorded at intervals less than
1 hour to understand the severity of storms. Long-term and detailed metrological data are needed as
input for the design of the tailings impoundment facility and surface water control facilities.
The water quality baseline sampling has not included specific sampling events to establish a
baseline characterization trend with seasonal variability. SRK recommends that quarterly sampling
be re-established to coincide with the variation in the wet and dry seasons. The groundwater quality
results exhibited abnormally high concentrations of total suspended solids. In SRK’s experiencethese levels can be due to improper monitor well construction, development or sampling techniques.
SRK recommends that the sampling methodology and water construction and development
procedures be further reviewed to see if the well filter pack is appropriate, the well development was
adequate and the sampling technique is acceptable to international standards.
Consultation with the community should be continued. The Social Management Plan proposed in the
ESIA should be prepared and aspects implemented.
A conceptual closure plan should be developed based on the results of the additional information
generated during the Phase I.
The estimated cost for performing the environmental and closure tasks mentioned above ranges
between US$150,000 to US$250,000.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 317/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 303
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
26.1.2 Phase II
Phase II work will be completing a feasibility study (having all fieldwork and testwork available from
Phase I).
Drilling/Geology/Resources:
The mineral resource model developed for the prefeasibility study will be quite adequate for a
feasibility study. No additional resource estimation work will be required, unless further definition of
the saprolite resource is requested in order to optimize the Project front-end saprolite processing
rate.
Open Pit Geotechnical/Hydrogeological Programs
Recommendations for future pit geotechnical/hydrogeological studies to complete a feasibility study
are below:
Incorporate the exploration drillhole data into the existing geotechnical database to refine the
rock mass model;
Update the geological and structural models; and
Conduct additional slope stability analyses (including numerical stress modeling).
The costs for the above pit geotechnical/hydrogeological feasibility level pit slope design and
dewatering plan are estimated to be US$80,000.
Mining
Additional mining studies required at the feasibility level of design for the Project include:
Detailed schedule for pre-production earthworks;
Incorporate additional geotechnical design data into the SE Pit design;
Feasibility level pit designs including dewatering structures;
Improved estimates of groundwater in-flow from local structures into the pit;
Assessment of a condemnation drilling program to confirm the locations of the low grade ore
stockpile, primary crusher and waste dumps;
Develop a feasibility level mine production schedule including monthly periods to start, and
completing the LoM schedule in quarterly periods to determine continuous ore exposure;
Assessment of an expanded articulated dump truck (ADT) fleet to mine part of the saprolite
waste and ore throughout most of the LoM mine production schedule;
Continued discussion with vendors for equipment quotes and detailed fuel usage;
Assessment of the adoption of a Maintenance and Repair Contract (MARC) as being an
optimum approach for mining equipment maintenance for the Toroparu Project;
Development of operational guidelines for treatment of any ARD waste rock; and
Further assessment of the low grade ore stockpiling approach with respect to water run-off
water quality management and oxidation of the ore. Given the competent nature of the fresh
rock (average UCS 150 MPa) it may be expected that oxidation will not penetrate RoM low
grade ore significantly.
The estimated cost for mining and mining related studies for a feasibility study are estimated to be
approximately US$250,000.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 318/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 304
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Saprolite Stockpile
For feasibility level the saprolite stockpile and ore re-handling will need to be defined. The stockpile
will need to be designed, and determination made whether re-handling will be by truck hauling or
pumping. The estimated cost for this portion of work is US$60,000.
Metallurgy and Processing
After the metallurgical results from the recommended testwork program are analyzed, the design
criteria will be reassessed and confirmed or adjusted. Additional trade-off studies should be
investigated and performed. Tt recommends Sandspring Resources perform a feasibility level study
on this criteria, process design, and mass balance revisions. As part of this study, Sandspring should
consider the incorporation of silver within the resource as a payable metal. This would be part of an
overall feasibility study. The estimated cost for this portion of the work ranges between US$500,000
to US$750,000,
On-Site Infrastructure
Tt recommends Sandspring Resources Ltd. perform a feasibility study design on the on-siteinfrastructure. This would be part of an overall feasibility study effort. The estimated cost for this
portion of the work is US$250,000 to US$350,000.
Water Supply
Tt recommends Sandspring Resources Ltd. confirm the water supply source, quality and quantity
requirements. The estimated cost for this portion of the work is US$30,000.
Wastewater Treatment
Tt recommends Sandspring Resources Ltd. confirm the wastewater treatment, discharge point,
quality and quantity requirements. The estimated cost for this portion of the work is US$30,000.
Tailings Management Area
Recommended work for feasibility design of the Tailings Management Area includes the following:
TMA Feasibility Design including the following main tasks:
o Site characterization: field program results compilation, design basis update and
hydrology parameters review;
o Feasibility level tailings characterization;
o Tailings facility layout, staging optimization, deposition modeling and analysis;
o Water management and water balance;
o Construction schedule and quantities; and
o Estimated cost (including a 25% contingency): US$300,000.
Off-site Infrastructure
Logistics Phase II = US$7,000
o Availability and costs of desired barge service;
o Further verification of the navigability of the Cuyuni River for desired barge traffic;
Pre-Design Engineering Phase II – US$20,000
o Detailed boundary and topographical survey of Pine Tree Landing and road section from
Pine Tree Landing to Toll House. US$300,000.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 319/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 305
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Feasibility Study Project Management and Other Disciplines
Additional feasibility study Project management and other discipline studies required at the feasibility
level of design for the Project include:
Feasibility study Project management;
Review and risk analysis;
Economic modeling;
Other as required; and
Report compilation.
The estimated costs for these items for a feasibility study are estimated to range between
US$250,000 and US$300,000.
26.1.3 Summary of Recommended Work Program Costs
A summary of the estimated costs for the Phase I Programs and Phase II Studies to complete a
feasibility study are shown in Table 26.1.3.1.
Table 26.1.3.1: Cost Summary for Recommended Work for FS Completion
Recommended Work ProgramsBase Estimate
(US$)Upper Limit Estimate
(US$)Phase I Programs – Fieldwork and TestworkPit Geotechnical/Hydrogeological Program 270,000 270,000Condemnation Drilling Program 1,330,000 1,330,000Metallurgy and Processing Testwork 225,000 225,000On-Site Infrastructure Geotechnical Site Investigation 75,000 100,000Tailings Management Area Program 430,000 480,000Off-Site Infrastructure Program 115,000 115,000Site Environmental Program 150,000 250,000Phase I Totals $2,595,000 $2,770,000
Phase II Studies – Feasibility Study Completion Pit Geotechnical/Hydrogeological Studies 80,000 80,000Mining Studies 250,000 250,000Saprolite Stockpile Design 60,000 60,000Metallurgy and Processing Studies 500,000 750,000On-Site Infrastructure Studies 310,000 410,000Tailings Management Area Studies 300,000 300,000Off-Site Infrastructure Studies 27,000 27,000Site Environmental Studies/Report 50,000 50,000Feasibility Study Project Mgmt and Other Disciplines 250,000 300,000Phase II Totals $1,827,000 $2,227,000
Phase I and Phase II Totals $4,422,000 $4,997,000
Source: SRK based on other consultants’ submissions.Costs excluded existing camp operating costs.Costs excluded for construction of accesses.
The estimated costs for completing Phase I range between US$2,595,000 and US$2,770,000. The
estimated costs for completing Phase II range between US$1,777,000 and US$2,177,000.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 320/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 306
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
27 References American Water Works Association, (1984). Design and Construction of Small Water Systems: A
Guide for Managers,
British Columbia Ministry of Environment (2012). Approved and Working Water Quality Guidelinesfor the Protection of Freshwater Aquatic Life. British Columbia Ministry of Environment,
Environmental Protection Division (http://www.env.gov.bc.ca/wat/wq/wq_guidelines.html).
Caterpillar Inc., (2012). Caterpillar Performance Handbook Edition 42, Caterpillar Publications,
Peoria, Illinois, 27 Sections.
Canadian Council of Ministers of the Environment (2012). Water Quality Guidelines for the Protection
of Aquatic Life (http://ceqg-rcqe.ccme.ca/).
Dardenne M.A. and Schobbenhaus C., (2003). Metallogeny of the Guiana Shield. Géologie de
France 2-3-4, p. 291-319.
Delor C., Roever E.W.F., Lafon J.M., Lahondère D., Rossi P., Cocherie A., Guerrot C. and Potrel A., (2003). The Bakhuis ultrahigh-temperature granulite belt (Surinam): Implications fro late
Transamazonian crustal stretching in a revisited Guiana Shield framework (2è Ed.):
Géologie de France, vol. 2-4, p. 207-230.
Dubé B. and Gosselin P., (2007). Greenstone-Hosted Quartz-Carbonate Vein Deposits. In
Goodfellow, W.D., ed., Mineral Deposits of Canada : A Synthesis of Major Deposit-Types,
District Metallogeny, the Evolution of Geological Provinces, and Exploration Methods:
Geological Association of Canada, Mineral Deposits Division, Special Publication No. 5, p.
49-73
ETK Inc. (2012). Final environmental and social impact assessment, Toroparu Gold and Copper
Mine, January, 2012, 335 p.
Fraga L.M., Reis N.J. and Agnol R.D., (2009). Cauarane – Coeroeni Belt - The Main Tectonic
Feature of the Central Guyana Shield, northern Amazonian Craton. International Geological
Congres , 33. Oslo, Norway. Abstract.
Gibbs A.K. and Barron C.N., (1993). The Geology of the Guiana Shield. Oxford University Press,
New York., Claredon Press. 245 p.
Guyana Environmental Protection Agency (2012). Environmental Permit No. 20050201-ETKIO.
Issued by Guyana Environmental Protection Agency for ETK Inc., June 2012, 13 p.
Hirdes W., Davis D.W., Ludtke G. and Konan G., (1996). Two generations of Birimian
(Paleoproterozoic) volcanic belts in northeastern Côte d’Ivoire (West Africa): consequences
for the “Birimian controversy”. Precambrian Research 80, p. 173-191.
Hollister V.F., (1992). On a proposed plutonic porphyry-gold deposit model. Nonrenewable
Resources 1 (9), p. 293-302.
IUCN (2010). International Union for Conservation of Nature. Web. 01 May 2013. <http://iucn.org/>.
InfoMine USA, Inc., (2012). Mine and Mill Equipment Costs, Spokane Valley, Washington.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 321/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 307
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
InfoMine USA Inc., (2013). Mining Cost Service, Spokane Valley, Washington.Klein E.L., Moura
C.A.V., Krymsky R.S. and Griffin W.L., 2005. The Gurupi Belt, northern Brazil :
Lithostratigraphy, geochronology, and geodynamic evolution. Precambrian Res. 141, p. 83-
105
Inspectorate. (2013) Prefeasibility Metallurgical Testing to Recover Gold on Samples fromSandspring’s Toroparu Project, Guyana. Prepared for Sandspring Resources Ltd. Report
dated February 18, 2013.
International Finance Corporation World Bank Group (2007). Environmental, Health and Safety
Guidelines for Mining, December 10, 2007, p. 26.
International Network for Acid Prevention (2012). The Global Acid Rock Drainage (GARD) Guide.
(http://www.gardguide.com/index.php).
Jacobs Minerals Canada Inc. (2011). SAG Versus HPGR Trade-off Study Toroparu Project.
Prepared for Sandspring Resources Ltd. Report dated November 18, 2011.
Jacobs Minerals Canada Inc. (2012). 15KTPD SAG Versus HPGR Trade-Off Study – ToroparuProject; Project 1878 – DRAFT. Prepared for Sandspring Resources Ltd. Report dated
January 13, 2012.
Jacobs Minerals Canada Inc. (2013). SAG Versus HPGR Trade-off Study – Toroparu Project;
CD1878.00. Prepared for Sandspring Resources Ltd. Report dated May 1, 2013.
Jacobs Minerals Canada Inc. (2013). Trade Off Study: SAG vs HPGR – 15k with future expansion;
Project 1878 – Rev A. Prepared for Sandspring Resources Ltd. Report dated January 31,
2013.
Klohn Crippen Berger (2011). Draft Tailings Storage Facility Alternatives Selection Assessment, draft
report prepared for Sandspring Resources Limited, December 5, 2011, 269 p.
Klohn, Krippen, Berger, (2012). Toroparu Geotechnical site Characterization-DRAFT. March 8.
Klohn Crippen Berger (2012a). Toroparu Project, Baseline ARD/ML Characterization – Waste Rock
and Low Grade Ore – Static Tests: unpublished report prepared for Sandspring Resources
Limited, May 5, 2012, 78 p.
Klohn Crippen Berger (2012b). Draft Toroparu Project, Acid Rock Drainage and Metal Leaching
(ARD/ML) Characterization Program, Waste Rock Short-term Leach Test Results:
unpublished draft report prepared for Sandspring Resources Limited, December 21, 2012,
31 p.
Klohn Crippen Berger Ltd (2012c) – “Toroparu Tailings Site Selection Assessment”.
Klohn Crippen Berger Ltd (2012d) – “Toroparu Geotechnical Site Characterization-DRAFT”. March 8.
Klohn Crippen Berger (2013). Toroparu Project, Baseline Geochemical (ARD/ML) Characterization
for ARD/ML Prediction, Draft: unpublished draft report prepared for Sandspring Resources
Limited, May 8, 2013, 103 p.
Knight Piésold Ltd. (2013). Toroparu Project – Prefeasibility Pit Slope Design Report.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 322/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 308
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Lang J.R. and Baker T., 2001. Intrusion-related gold systems : the present level of understanding.
Mineralium Deposita 36, p. 477-489.
Liègeois J.P., Claessens L.W., Camara D. and Klerkx J., (1991). Short-lived Eburnian orogeny in
southern Mali. Geology, tectonics, U-Pb and Rb-Sr geochronology. Precambrian Research
50, p. 111-136.
Lompo M., (2009). Geodynamic evolution of the 2.25-2.0 Ga Paleoproterozoic magmatic rocks in
the Man-Leo Shield of the West African Craton. A model of subsidence of an oceanic
plateau. In Palaeoproterozoic Supercontinents and Global Evolution. Geological Society,
London, Special Publications, 323, p. 231-254.
McCuaig T.C., Behn M., Stein H.J., Hagemann S.G., McNaughton N., Cassidy K.F., Champion D.
and Wyborn L., (2001). The Boddington gold mine : a new style of Archean Au-Cu deposit.
AGSO – Geoscience Australia 2001, p. 453-455.
Meixner (2008). Technical Report on the Toroparu Copper-Gold Prospect, Upper Puruni River Area,
Guyana”, dated July 10, 2008, revised August 8, 2008 with a second revision dated October
15, 2008.
Milesi J.P., Ledru P., Feybess J.L., Dommanget A. and Marcoux E., (1992). Early Proterozoic ore
deposits and tectonics of the Birimian orogenic belt, West Africa. Precambrian Research 58,
p. 305-344
Mine Development Associates, (2007). NI 43-101 Technical Report, Update Feasability Study, Las
Christinas Project, Venezuela (Crystallex International Corporation).
Mine Environment Neutral Drainage (2009) Prediction Manual for Drainage Chemistry from Sulphidic
Geologic Materials MEND Report 1.20.1. NRCan.
Morgan Building Systems. 2013. Budget Proposal for Man Camp. March 7.
P&E Mining Consultants, January 06, (2009); Technical Report, Resource Estimate on the Toroparu
Gold-Copper Deposit, Upper Puruni River Area, Guyana; NI 43-101 technical report No 153
prepared by P&E Mining Consultants Inc, for Sandspring Resources Ltd., Effective date of
October 26, 2008, 105 pages.
P&E Mining Consultants, (2010). Technical Report, Updated Resource Estimate on the Toroparu
Gold-Copper Deposit, Upper Puruni River Area, Guyana; NI 43-101 technical report No 186
prepared by P&E Mining Consultants Inc, for Sandspring Resources Ltd., Effective date of
May 12, 2010, Report Date July 16, 2010, 129 pages.
P&E Mining Consultants, March 12, 2012; Technical Report, Updated Resource Estimate and
Preliminary Economic Assessment of the Toroparu Gold-Copper Deposit, Upper PuruniProperty, Upper Puruni River Area, Guyana; NI 43-101 Technical Report No 234 prepared
by P&E Mining Consultants Inc, for Sandspring Resources Ltd., Effective Date of January
30, 2012, 215 pages.
P&E Mining Consultants, May 05, 2011; Technical Report, Updated Resource Estimate and
Preliminary Economic Assessment of the Toroparu Gold-Copper Deposit, Upper Puruni
Property, Upper Puruni River Area, Guyana; NI 43-101 Technical Report No. 208 prepared
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 323/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 309
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
by P&E Mining Consultants Inc., for Sandspring Resources Ltd., Effective Date of April 30,
2011, 213 pages.
P&E Mining Consultants, October 13, 2010; Technical Report, Updated Resource Estimate on the
Toroparu Gold-Copper Deposit, Upper Puruni River Area, Guyana; NI 43-101 Technical
Report No 193 prepared by P&E Mining Consultants Inc, for Sandspring Resources Ltd.,Effective date of September 12, 2010, 145 pages.
Pincock, Allen & Holt, 2008. NI 43-101 Technical Report, Update Feasability Study, Las Brisas
Project, Venezuela (Gold Reserve Inc.).
Planning for an Individual Water System. American Association for Vocational Instructional Materials,
1982
Ray, Brian, March 21, 2013;, Toroparu Property Check Assay Report, Sandspring Resources
internal Memorandum, 24 p.
Resource Development Inc. (2011) Gravity Test Results. Prepared for Sandspring Resources Ltd.
Report dated May 24, 2011.
Rowley D.B. and Pindell J.L., 1989. End Paleozoic-Early Mesozoic Western Pangean
Reconstruction and its Implications for the Distribution of Precambrian and Paleozoic Rocks
around Meso-America. Precambrian Research 42, p. 411-444.
SGS Canada Inc. (2013) A Prefeasibility Study of Gold Ore Containing Low and Average Copper
Grade from the Toroparu Deposit; Project 12520-002 – Final Report. Prepared for
Sandspring Resources Ltd. Report dated January 9, 2013.
SGS Canada Inc. (2011) A Deportment Study of Gold Deportment Study for a Sample from the
Toroparu Cu-Au Porphyry Property; Project 125020-001 – Final Report. Prepared for
Sandspring Resources Ltd. Report dated May 18, 2011.
SGS Canada Inc. (2012) A Metallurgical Evaluation of the Master Composite and Variability Samples
from the Toroparu Deposit; Project 12520-001 – Report 2. Prepared for Sandspring
Resources Ltd. Report dated November 19, 2012.
SGS Canada Inc. (2012) A Preliminary Metallurgical Evaluation of a Master Composite from the
Toroparu Deposit; Project 12520-001 – Report 1. Prepared for Sandspring Resources Ltd.
Report dated October 3, 2012.
SGS Lakefield Research Limited. (2009) An Investigation Into the Recovery of Gold and Copper
From the Toroparu Deposit of Sandspring Resources (Guyana); Project 12039-001 – Final
Report. Prepared for ETK. Report dated June 22, 2009.
Sidder G.B., 1995. Mineral Deposits of the Venezuelan Guayana Shield. U.S. Geological Survey
Bulletin 2124, 20 p.
Taylor G.H., Coste B., Lambert A., and Zeegers H., 1989. Geochemical signature (bedrock and
Saprolite) of gold mineralization and associated hydrothermal alteration at Dorlin, French
Guyana. Journal of Geochemical Exploration 32, p. 59-60
Tetra Tech, 2013. NI 43-101 Technical Report, Update Feasibility Study, Aurora Gold Project,
Guyana (Guyana Goldfields Ltd.)
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 324/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Page 310
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Voicu G., Bardoux M., Jébrak, M. and Crépeau R., 1999. Structural, Mineralogical and
Geochemical Studies of the Paleaproterozoic Omai Gold Deposit, Guyana. Economic
Geology 94, p. 1277-1304
Voicu G., Bardoux M. and Stevenson R., 2001. Lithostratigraphy, geochrono-logy and gold
metallogeny in the northern Guiana Shield, South America: a review. Ore Geology Reviews18, p. 211-236.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 325/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Appendices
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Appendices
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 326/340
SRK Consulting (U.S.), Inc.NI 43-101 Technical Report – Toroparu Gold Project Appendices
PC/MLM Toroparu_NI43-101_TechnicalReport_349800.020_044_MLM.docx May 24, 2013
Appendix A: Cert ificates of Authors
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 327/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 328/340
SRK Consulting (US) Inc.
Suite 240, 3275 West Ina Road
Tucson, AZ 85741
T: 520 544 3688
F: 520 544 9853
www.srk.com
U.S. Offices:
Anchorage 907.677.3520
Denver 303.985.1333
Elko 775.753.4151
Fort Collins 970.407.8302
Reno 775.828.6800
Tucson 520.544.3688
Mexico Office:
Guadalupe,
Zacatecas
52.492.927.8982
Canadian Offi ces:
Saskatoon 306.955.4778
Sudbury 705.682.3270
Toronto 416.601.1445
Vancouver 604.681.4196
Yellowknife 867.873.8670
Group Offices:
Africa
Asia
Australia
Europe
North America
South America
CERTIFICATE OF AUTHOR
I, Al lan V. Moran, a Registered Geologist and a Certified Professional Geologist, do herebycertify that:
1. I am currently employed as a consulting geologist to the mining and mineral explorationindustry, as Principal Geologist with SRK Consulting (U.S.) Inc, with an office address of3275 W. Ina Rd., Tucson, Arizona, USA, 85741.
2. I graduated with a Bachelors of Science Degree in Geological Engineering from theColorado School of Mines, Golden, Colorado, USA; May 1970.
3. I am a Certified Professional Geologist through membership in the American Institute of
Professional Geologists, CPG - 09565, and have been since 1995; and I am a RegisteredGeologist in the State of Oregon, USA, # G-313, and have been since 1978.
4. I have been employed as a geologist in the mining and mineral exploration business,continuously, for the past 42 years.
5. I have read the definition of “qualified person” set out in National Instrument 43-101 (“NI 43-101”) and certify that by reason of my education, affiliation with a professional association(as defined in NI 43-101) and past relevant work experience, I fulfill the requirements to bea “qualified person” for the purposes of NI 43-101. The Technical Report is based upon mypersonal review of the information provided by the issuer. My relevant experience for thepurpose of the Technical Report is:
Manager, Exploration North America for Cameco Gold Inc., 1998-2002:
Vice President and U.S. Exploration Manager for Independence Mining Company,Reno, Nevada, 1990-1993;
Exploration Geologist for Freeport McMoRan Gold, 1980-1990;
Gold exploration experience, as an exploration geologist, from 1980 through 2002; andwork with gold deposits since 2002 as a consultant with SRK Consulting (U.S.) Inc;
Experience in the above positions working with and reviewing resource estimationmethods and models, in concert with resource estimation geologists and engineers.
As a consultant, from 2003 to 2013, I have completed several NI 43-101 Technicalreports.
6. I am responsible for all of Sections 6 through 12, and for inputs to Sections 1, 25, and 26 ofthe Technical Report titled “NI 43-101 Technical Report, Prefeasibility Study, Toroparu GoldProject, Upper Puruni River Area, Guyana.”, with an effective date of May 08, 2013 (the
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 329/340
SRK Consulting Page 2
“Technical Report”) relating to Sandspring Resources Ltd.’s interests in the Toroparu GoldProject . I have personally visited the Project on April 18 and 19, 2012, for 2 days.
7. I have not had prior involvement with the property that is the subject of this TechnicalReport.
8. As of May 08, 2013, the effective date of this report, to the best of my knowledge,
information and belief, the Technical Report contains all the scientific and technicalinformation that is required to be disclosed to make the Technical Report not misleading.
9. I am not aware of any material fact or material change with respect to the subject matter ofthe Technical Report that is not reflected in the Technical Report, for which the omission todisclose would make the Technical Report misleading.
10. I am independent of the issuer applying all of the tests in Item 1.5 of National Instrument43-101.
11. I have read National Instrument 43-101 and Form 43-101F1, and the Technical Report hasbeen prepared in compliance with that instrument and form.
12. I consent to the filing of the Technical Report with any stock exchange and other regulatoryauthority and any publication by them, including electronic publication in the publiccompany files on their websites accessible to the public, of the Technical Report.
Dated in Tucson, Arizona, May 17, 2013.
Allan V. Moran, R. Geol., CPG
AIPG CPG – 09565
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 330/340
Tetra Tech, Inc.
350 Indiana Street, Suite 500, Golden, CO 80401
Tel 303-217-5700 Fax 303-217-5705 tetratech.com
C E R T I F I C A T E O F Q U A L I F I E D P E R S O N
D. Erik Spiller
As co-author of this report entitled “NI 43-101 Technical Report, Toroparu Gold Project, Upper Puruni River Area,Guyana”, with an effective date of 8 May, 2013 (the “Technical Report”), I, D. Erik Spiller, do hereby certify that:
1. I am employed as a Vice-President - Principal Metallurgist by, and carried out this assignment for: Tetra Tech,Inc., 350 Indiana Street, Suite 500, Golden, Colorado 80401, USA tel. (303) 217-5700 email:[email protected].
2. I hold the following academic qualifications: B.Sc.in Metallurgical Engineering, Colorado School of Mines, 1970.
3. I am a Qualified Professional (QP) member of the Mining and Metallurgical Society of America (MMSA#01021QP). In addition, I am a Registered (QP) member of Society for Mining, Metallurgy, and Exploration, Inc.(SME #3051820RM).
4. I have more than 40 years of relevant experience working as a metallurgical engineer in the mineral resourceindustry. During this career I held responsible positions in process research, process development, engineering,and senior management. In addition, since 2008 I have served as an appointed Research Professor at theColorado School of Mines; this was preceded by 15 years as an Adjunct Instructor at the same institution. I
lecture in mineral beneficiation and direct graduate students conducting metallurgical research in my area ofexpertise.
5. By reason of education, experience and qualified professional registration, I fulfill the requirements of aQualified Person as defined in NI 43-101.
6. I did not personally visit the Toroparu Gold Project site. I did visit SGS Canada to inspect the on-goingmetallurgical test work. My most recent personal inspection of the laboratory was November 1, 2012 for one day.
7. I am responsible for the preparation of Sections 13, 17, 18.1.8, 21.2.2, 21.2.3, and the portions of Sections 1,25 and 26 summarized therefrom, of the Technical Report.
8. I am independent of Sandspring Resources Ltd., as defined in Section 1.5 of NI 43-101.
9. I have had no previous involvement with the property.
10. I have read NI 43-101 and the portions of this report for which I am responsible have been prepared incompliance with the instrument.
11. As of the date of this certificate to the best of my knowledge, information and belief, the sections of thisTechnical Report for which I am responsible contain all scientific and technical information that is required to bedisclosed to make this report not misleading.
Dated this 24th day of May 2013
SIGNED AND SEALED
Signature of Qualified Person
D. Erik Spiller
Print Name of Qualified Person
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 331/340
Tetra Tech, Inc.
3801 Automation Way, Suite 100, Fort Collins, CO 80525Tel 970-223-9600 Fax 970-223-7171 tetratech.com
C E R T I F I C A T E O F Q U A L I F I E D P E R S O N
Daniel Lloyd Evans
As co-author of this report entitled “NI 43-101 Technical Report, Toroparu Gold Project, Upper Puruni River Area,Guyana”, with an effective date of 8 May, 2013 (the “Technical Report”), I, Daniel Lloyd Evans, do hereby certifythat:
1. I am employed as a Senior Water Resources Engineer by, and carried out this assignment for: Tetra Tech, Inc.,3801 Automation Way, Suite 100, Fort Collins, CO, 80525 tel. (970) 223-9600 email: [email protected] .
2. I hold the following academic qualifications: B.A. Geophysics, Occidental College, 1988; M.S. Civil Engineering – emphasis in Hydrology, Colorado State University, 1991.
3. I am a Professional Engineer registered with the State of Colorado, USA. (Registration number 32081).
4. I have practiced my profession continuously since 1991. Since 1994, I have engineered infrastructure designsfor a variety of early and advanced base mineral projects in the Yukon, Saskatchewan, Alaska, Australia, State ofWashington, and the State of Nevada.
I have worked in the minerals industry for 11 years; my work experience includes 11 years as a water resources
engineer working in the field of surface water hydrology and hydraulics.
5. I do, by reason of education, experience and professional registration, fulfill the requirements of a QualifiedPerson as defined in NI 43-101.
6. My most recent personal inspection of the Property was October 19 – 21, 2012 for three days.
7. I am responsible for water management Sections 16.9.1 through 16.9.3, 18.1.2, 18.1.9, 18.1.10 and portions ofSections 1, 25 and 26 summarized therefrom, of the Technical Report.
8. I am independent of Sandspring Resources Ltd., as defined in Section 1.5 of NI 43-101.
9. I have had no previous involvement with the property.
10. I have read NI 43-101 and the portions of this report for which I am responsible have been prepared incompliance with the instrument.
11. As of the date of this certificate to the best of my knowledge, information and belief, the sections of thisTechnical Report for which I am responsible contain all scientific and technical information that is required to bedisclosed to make this report not misleading.
Dated this 24th day of May 2013
Signature of Qualified Person
Daniel Lloyd Evans
Print Name of Qualified Person
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 332/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 333/340
SRK Tucson
3275 W. Ina Road
Suite 240
Tucson, AZ 85741
T: 520 544 3688
F: 520 544 9853
www.srk.com
U.S. Offices:
Anchorage 907.677.3520
Denver 303.985.1333
Elko 775.753.4151
Fort Collins 970.407.8302
Reno 775.828.6800
Tucson 520.544.3688
Mexico Offices:
Zacatecas 52.492.927.8982
Querétaro 52.442.218.1030
Canadian Offi ces:
Saskatoon 306.955.4778
Sudbury 705.682.3270
Toronto 416.601.1445
Vancouver 604.681.4196
Yellowknife 867.873.8670
Group Offices:
Africa
Asia
Australia
Europe
North America
South America
CERTIFICATE OF AUTHOR
I, Dawn H. Garcia, P.G., CPG, do hereby certify that:
1. I am a Principal Hydrogeologist of SRK Consulting (U.S.), Inc., 3275 W Ina Road, Suite 240, Tucson Arizona 85741.
2. This certificate applies to the technical report titled “NI 43-101 Technical Report, Prefeasibility Study,Toroparu Gold Project, Upper Puruni River Area, Guyana” with an Effective Date of May 8, 2013 (the“Technical Report”).
3. I graduated with a degree in Geological Sciences from Bradley University in 1982. In addition, I haveobtained a M.S., Geology, 1995, California State University Long Beach. I am a Certified ProfessionalGeologist of the American Institute of Professional Geologists (CPG-08313) and a Registered Member of
the Society of Mining Metallurgy, and Exploration, Inc. (RM-4135993).
4. I have worked as a geologist/hydrogeologist for a total of 28 years since my graduation from university.My relevant experience includes environmental compliance permitting, hydrogeological studies andgeotechnical studies at mining and processing operations.
5. I have read the definition of “qualified person” set out in National Instrument 43-101 (NI 43-101) andcertify that by reason of my education, affiliation with a professional association (as defined in NI 43-101)and past relevant work experience, I fulfill the requirements to be a “qualified person” for the purposes ofNI 43-101.
6. I have not visited the property and thus I have relied on the descriptions of others.
7. I am responsible for the preparation of Sections 20 (excluding geochemistry portions of 20.1 and TMAportion of 20.7.1), and portions of 1, 25 and 26 summarized therefrom, of this Technical Report.
8. I am independent of the issuer applying all of the tests in section 1.5 of NI 43-101.9. I have not had prior involvement with the property that is the subject of the Technical Report.
10. I have read NI 43-101 and Form 43-101-F1 and the sections of the Technical Report I am responsible forhave been prepared in compliance with that instrument and form.
11. As of 8 May 2013, to the best of my knowledge, information and belief, the sections of the TechnicalReport I am responsible for contains all scientific and technical information that is required to bedisclosed to make the Technical Report not misleading.
Dated this 8th Day of May, 2013, at Tucson, Arizona, USA.
________________________________ “Sealed ”
Dawn H. Garcia
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 334/340
SRK Denver
Suite 3000
7175 West Jefferson Avenue
Lakewood, CO 80235
T: 303.985.1333
F: 303.985.9947
www.srk.com
U.S. Offi ces:
Anchorage 907.677.3520
Denver 303.985.1333
Elko 775.753.4151
Fort Collins 970.407.8302
Reno 775.828.6800
Tucson 520.544.3688
Mexico Office:
Guadalupe, Zacatecas
52.492.927.8982
Canadian Offi ces:
Saskatoon 306.955.4778
Sudbury 705.682.3270
Toronto 416.601.1445
Vancouver 604.681.4196
Yellowknife 867.873.8670
Group Offices:
Africa
Asia
Australia
Europe
North America
South America
QP_Cert_Rodrigues_Toroparu_2013
CERTIFICATE OF AUTHOR
I, Fernando Rodrigues, B.S. Mining, MMSA do hereby certify that:
1. I am Senior Mining Engineer of:
SRK Consulting (U.S.), Inc.7175 W. Jefferson Ave, Suite 3000Denver, CO, USA, 80235
2. I graduated with a Bachelors of Science degree in Mining Engineering from South Dakota School ofMines and Technology in 1999.
3. I am a QP member of the MMSA.
4. I have worked as a Mining Engineer for a total of 13 years since my graduation from South DakotaSchool of Mines and Technology in 1999. My relevant experience includes contributions to multiple,feasibility, pre-feasibility, preliminary assessments, due diligence and competent person reports; designand implementation, short term mine design, dump design, haulage studies, blast design, ore control,grade estimation, and database management.
5. I have read the definition of “qualified person” set out in National Instrument 43-101 (NI 43-101) andcertify that by reason of my education, affiliation with a professional association (as defined in NI 43-101)
and past relevant work experience, I fulfill the requirements to be a “qualified person” for the purposes ofNI 43-101.
6. I am responsible for the preparation of Sections 15, 16 (except for sub-section 16.2, 16.8 and 16.9), andportions of Sections 1, 25 and 26 summarized therefrom, of the technical report titled “NI 43-101Technical Report, Prefeasibility Study, Toroparu Gold Project, Upper Puruni River Area, Guyana”, withan effective date of May 08, 2013, and dated May 24, 2013 (the “Technical Report”). I have not visitedthe property.
7. I have not had prior involvement with the property that is the subject of the Technical Report.
8. I am independent of the issuer applying all of the tests in section 1.5 of National Instrument 43-101.
9. I have read NI 43-101 and Form 43-101F1, and the Technical Report has been prepared in compliancewith that instrument and form.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 335/340
SRK Consulting Page 2
QP_Cert_Rodrigues_Toroparu_2013
10. I consent to the filing of the Technical Report with any stock exchange and other regulatory authority andany publication by them for regulatory purposes, including electronic publication in the public companyfiles on their websites accessible by the public, of the Technical Report.
11. As of May 8, 2013, to the best of my knowledge, information and belief, the portion(s) of the TechnicalReport I am responsible for contains all scientific and technical information that is required to be
disclosed to make the Technical Report not misleading.
Dated this 24th Day of May, 2013.
“Signed” “Sealed” ________________________________Fernando Rodrigues, B.S. M.Eng, MMSA MMSA # 01405QP
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 336/340
SRK Denver
Suite 3000
7175 West Jefferson Avenue
Lakewood, CO 80235
T: 303.985.1333
F: 303.985.9947
www.srk.com
CERTIFICATE OF AUTHOR
I, Frank Daviess, MAusIMM, Registered SME do hereby certify that:
1. I am currently employed as a consulting resource geologist to the mining and mineral explorationindustry and I am currently under contract as an Associate Resource Geologist of SRK Consulting(U.S.), Inc., 7175 W. Jefferson Ave, Suite 3000, Denver, CO, USA, 80235.
2. This certificate applies to the technical report titled ““NI 43-101 Technical Report, Prefeasibility Study,Toroparu Gold Project, Upper Puruni River Area, Guyana”” with an Effective Date of effective date ofMay 8, 2013 and dated May 24, 2013 (the “Technical Report”).
3. I graduated from the University Of Colorado, Boulder, Colorado, USA with a B.A. in Geology in 1971 anda M.A. in Natural Resource Economics and Statistics in 1975. I am a Member of the AustralasianInstitute of Mining and Metallurgy (Registration No. 226303). I am a Registered Member of the Societyfor Mining, Metallurgy and Exploration, Inc. (Registration No. 0742250). I have been employed as ageologist in the mining and mineral exploration business, continuously, for the past 38 years, since mygraduation from university. I am qualified as a competent person for the resource estimation of manycommodities under the JORC/CIM guidelines and also have experience with Sarbanes-Oxley (SOX)compliance, due diligence auditing and risk assessment.
4. I have read the definition of “qualified person” set out in National Instrument 43-101 (NI 43-101) andcertify that by reason of my education, affiliation with a professional association (as defined in NI 43-101)and past relevant work experience, I fulfill the requirements to be a “qualified person” for the purposes ofNI 43-101.
5. I visited the property on November 10 through 12, 2010 for three days.
6. I am responsible for the resource estimation Section 14 and portions of Sections 1, 25 and 26summarized therefrom, of this Technical Report.
7. I am independent of the issuer applying all of the tests in section 1.5 of NI 43-101. I have not had prior
involvement with the property that is the subject of the Technical Report.
8. I have read NI 43-101 and Form 43-101-F1 and the sections of the Technical Report I am responsible forhave been prepared in compliance with that instrument and form.
9. As of the aforementioned Effective Date, to the best of my knowledge, information and belief, thesections of the Technical Report I am responsible for contains all scientific and technical information thatis required to be disclosed to make the Technical Report not misleading.
Dated this 24th Day of May, 2013.
“signed” “sealed”
________________________________
Frank Daviess
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 337/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 338/340
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 339/340
SRK Denver
Suite 3000
7175 West Jefferson Avenue
Lakewood, CO 80235
T: 303.985.1333
F: 303.985.9947
www.srk.com
U.S. Offi ces:
Anchorage 907.677.3520
Denver 303.985.1333
Elko 775.753.4151
Fort Collins 970.407.8302
Reno 775.828.6800
Tucson 520.544.3688
Mexico Office:
Guadalupe, Zacatecas
52.492.927.8982
Canadian Offi ces:
Saskatoon 306.955.4778
Sudbury 705.682.3270
Toronto 416.601.1445
Vancouver 604.681.4196
Yellowknife 867.873.8670
Group Offices:
Africa
Asia
Australia
Europe
North America
South America
QP_Cert_Clarke_Toroparu_2013
CERTIFICATE OF AUTHOR
I, Peter Clarke, B.Sc., MBA, P. Eng. do hereby certify that:
1. I am a Principal Mining Engineer of:
SRK Consulting (U.S.), Inc.7175 W. Jefferson Ave, Suite 3000Denver, CO, USA, 80235
2. I graduated with a B.Sc. degree in Mining Engineering granted by the University of Leeds in 1975 and anMBA granted by the University of Phoenix in 2002.
3. I am a registered member in good standing of the Association of Professional Engineers andGeoscientists of British Columbia since 1982.
4. I have worked as a mining engineer for a total of 28 years since my graduation from university.experience as an open-pit mining engineer in mining operations and mine engineering consulting.Experience includes mining of precious metals, copper, lead, zinc, nickel, and industrial minerals in North
America and overseas. I have an extensive background in open-pit mine design, planning, productionscheduling, equipment selection and cost estimating. Studies conducted include property evaluations,scoping studies, feasibilities, mine planning optimizations, and due diligence.
5. I have read the definition of “qualified person” set out in National Instrument 43-101 (NI 43-101) andcertify that by reason of my education, affiliation with a professional association (as defined in NI 43-101)and past relevant work experience, I fulfill the requirements to be a “qualified person” for the purposes ofNI 43-101.
6. I am responsible for project economics, mining equipment and costs and other information in Sections 2through 5, 16.8, 16.9.4, 19, 21 (except for 21.2.2, 21.2.3, 21.3.3 and 21.3.4), 22 through 24, and portionsof Sections 1, 25 and 26 summarized therefrom of the technical report titled “NI 43-101 TechnicalReport, Prefeasibility Study, Toroparu Gold Project, Upper Puruni River Area, Guyana”, with an effectivedate of May 8, 2013, and dated May 24, 2013 (the “Technical Report. I did not visit the property.
7. I have not had prior involvement with the property that is the subject of the Technical Report.
8. I am not independent of the issuer applying all of the tests in section 1.5 of National Instrument 43-101.
9. I have read NI 43-101 and Form 43-101F1, and the Technical Report has been prepared in compliancewith that instrument and form.
7/24/2019 NI 43-101 Technical Report Prefeasibility Study Toroparu Gold Project Upper Puruni River Area, Guyana
http://slidepdf.com/reader/full/ni-43-101-technical-report-prefeasibility-study-toroparu-gold-project-upper 340/340
SRK Consulting Page 2
10. I consent to the filing of the Technical Report with any stock exchange and other regulatory authority andany publication by them for regulatory purposes, including electronic publication in the public companyfiles on their websites accessible by the public, of the Technical Report.
11. As of May 08, 2013, the effective date of this report, to the best of my knowledge, information and belief,the Technical Report contains all the scientific and technical information that is required to be disclosed
to make the Technical Report not misleading.
Dated this 24th Day of May, 2013.
“Signed” “Sealed”
________________________________Peter Clarke, B.Sc., MBA, P. Eng. P.Eng Registration No.: 13473