Narrow Vein Mining Citicorp
description
Transcript of Narrow Vein Mining Citicorp
Chris TowseyChris TowseyChief Operating Officer, Citigold Corporation LtdChief Operating Officer, Citigold Corporation Ltd
Narrow Vein Mining. CASE STUDY.Narrow Vein Mining. CASE STUDY.Citigold’s perspective on weighing up the Citigold’s perspective on weighing up the benefits against the challenges of narrow benefits against the challenges of narrow
vein miningvein mining
1000 km625 miles
4 kilometres
Railw
ay
Previous mining (yellow) developed200km of underground drives andproduced 6.6 million ounces of gold
Processing Plant
Tailings dam
Stockholmmine
Washingtonmine
Declineportal
0 1km
XWarrior
mine
Warrior Mine
Diagram from Peters, 1987. EGRU Contrib 19
No. 2 Cross Vein(Maude St. Leger reef)
No. 2 Cross Vein (Maude St. Leger reef)
Processing Plant
Tailings dam
Stockholmmine
Washingtonmine
Declineportal
0 1km
XWarrior
mine
Warrior Mine
Development PlanWarrior mine & gold resource – Long section
Development PlanWarrior gold resource – drilling Cross Section
Cross sectionLooking West
BENEFITS OF MECHANISEDBENEFITS OF MECHANISEDNARROW VEIN MININGNARROW VEIN MINING
Low mining cost per ounceLow mining cost per ounce–– low tonnage to break, haul and milllow tonnage to break, haul and mill–– high grade per tonne high grade per tonne –– 13 13 g/tg/t–– floor of drive preservedfloor of drive preserved
Mining method:Longhole open stoping10m sub-levels
Atlas Copco Simba
BENEFITS OF MECHANISEDBENEFITS OF MECHANISEDNARROW VEIN MININGNARROW VEIN MINING
Low mining cost per ounceLow mining cost per ounce–– low tonnage to break, haul and milllow tonnage to break, haul and mill–– high grade per tonne high grade per tonne –– 13 13 g/tg/t–– floor of drive preservedfloor of drive preservedSafer than handSafer than hand--heldheld
MechanisedCut and fill
Shrink stoping
Mining method:Longhole open stoping10m sub-levelsExpansion slot byvertical crater retreat
BENEFITS OF MECHANISEDBENEFITS OF MECHANISEDNARROW VEIN MININGNARROW VEIN MINING
Low mining cost per ounceLow mining cost per ounce–– low tonnage to break, haul and milllow tonnage to break, haul and mill–– high grade per tonne high grade per tonne –– 13 13 g/tg/t–– floor of drive preservedfloor of drive preservedSafer than handSafer than hand--heldheldAccurate grade controlAccurate grade control
9.6 g/t Au1.1 g/t Au 7.0 g/t Au
Grade variationGrade variation
No. 2 Cross Vein in stope pillarshowing rapid pinch-out
0.1m
0.2m
0.7m
CHALLENGESCHALLENGES
Dilution Dilution –– planned and unplannedplanned and unplanned
Planneddilution
Ore
Overbreak
Unplanned dilution
Cross section
Ore SortingDilution removed by ore sorting
Photometric ore sorter
The 30% waste and
dilution removed
by sorting
Feed screenedand washed
OREWASTE
CHALLENGESCHALLENGES
Dilution Dilution –– planned and unplannedplanned and unplannedMultiple working faces requiredMultiple working faces required
Conventional long-section view of a shoot within a planar structurePayability of structure 30%
Drill pierce pointsbelow cut-off
Drill pierce pointsAbove cut-off
Extraction levels
Charters Towers structure with payable areas – no defined shootPayability of structure 30%70% chance of a barren hole
Drill pierce pointsbelow cut-off
Drill pierce pointsAbove cut-off
Extraction levels
Stope blocks
CHALLENGESCHALLENGES
Dilution Dilution –– planned and unplannedplanned and unplannedMultiple working faces requiredMultiple working faces requiredFlatFlat--dipping stopes dipping stopes –– difficult muckingdifficult mucking
Stope cleaning of 10m x 20m panelswill use water-jets rather than scrapers
Ore is jetted down the stope to a gully or sump
Mining CostsMining Costs
222853352TOTAL COST 21844ADMINISTRATION 5202SURFACE HAULAGE
4517710PROCESSING 151582236Sub-total 7429623Development 77291613Production
MINING
Total$/oz
Total$/Tonne
Ore
Labour$/Tonne
Ore
Materials$/Tonne
Ore
Thank you