Presented by: Dr. Nguyen Thanh Long

PresentationBAUXITE BLOCK MODELING AND RESERVE ESTIMATION

FOR THE WESTERN PART OF TAN RAI MINE

MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT

CONTENTS

1

Tan Rai bauxite mine, about 42 km2, locates in 3 communes: Loc Thang, Loc Phu and Loc Ngai in Bao Lam District, Lam Dong Province, 20km NE direction from Bao Loc town. It has geographical coordinates:

11038’08’’ - 11041’56’’ N 107049’54’’ - 107053’12’’ E

In this research, the western part of Tan Rai mining is concentrated for bauxite ore modeling and reserve estimation.

INTRODUCTION

2

– The boreholes grid in the area in which the C1 bauxite mineral reserve level was set up 200m-distance.

– The boreholes grid in the area in which the C1 bauxite mineral reserve level was set up 100m-distance.

INTRODUCTION

3

C1 level

B level

The bauxite reserves of Tan Rai mine were estimated according 2 different mineral reserve levels i.e., B and C1.

B: 198 drillholesC1: 553 drillholes

  Bauxite mineral reserve criteria for estimation– The bauxite mineral reserve of Tan Rai bauxite mining is calculated

according to decision 22/QĐ-HĐĐGTLKS which Chairman of Mineral Reserve Assessment Committee approved April 13, 2000.That are:Al2O3 volume in fined ore 40%

- ratio of grain size +1 mm 20%. - Silica module ( Al2O3/SiO2) for the fined ore 7.0

The thickness of industrial ore is at least 1.0 m

INTRODUCTION

4

Creating drillhole file

Viewing drillholes in 3D

Creating wireframe modeling for ore bodies

Creating strings of ore body in parallel sections

Creating BLOCK MODEL for the ore bodies

Grade interpolation

The results of reserve estimation and report

The reserves estimation

The grade interpolation results

Linking all strings in parallel sections to build the blank wireframe

PROCESS FOR MINERAL RESERVE ESTIMATION

IN DATAMINE SOFTWARE

5

Data preparation

collars.txt X, Y, Z coordinates of the drillhole collarssurveys.txt Downhole measurements of drillhole azimuth and inclinationassays.txt Mineral assays of drillhole samplesgeology.txt Drillhole sample lithology logspoint.txt Information about terrain surface: rivers, roads, contour, etc…

DATA PREPARATION

6

Principle data in Datamine

Data structure of collars, surveys, assays, geology, and point files

CollarsCollars GeologyGeology

SurveysSurveysAssaysAssays

X, Y, Z coordinates of the drillhole collars

Mineral assays of drillhole samples

Drillhole sample lithology logs

Downhole measurements of drillhole azimuth and inclination

Terrain surface (contour, river, road, ...)

Drillhole file

CREATING DRILLHOLE FILE

7

Datamine provides several different ways of drillhole view in the 2D or 3D for several purposes

8

VIEWING DRILLHOLES IN 3D

553 drillholes

198 drillholes

9

CREATING STRINGS OF ALL ORE BODIES (B LEVEL)

IN PARALLEL SECTIONS (35-45)Profile 35Profile 35Profile 36Profile 36Profile 37Profile 37Profile 38Profile 38Profile 39Profile 39Profile 40Profile 40Profile 41Profile 41Profile 42Profile 42Profile 43Profile 43Profile 44Profile 44

Profile 45Profile 45

10

CREATING STRINGS OF ALL ORE BODIES (C1 LEVEL)

IN PARALLEL SECTIONS (1-69)

Profile 1Profile 1Profile 3Profile 3Profile 5Profile 5Profile 7Profile 7Profile 9Profile 9Profile 11Profile 11

11

LINKING STRINGS IN PARALLEL SECTIONS TO CREATE THE BLANK WIREFRAME (C1 LEVEL)

12

LINKING STRINGS IN PARALLEL SECTIONS TO CREATE THE BLANK WIREFRAME (B LEVEL)

  Define block (PROTOM )– Identify block coordinates (X,Y,Z):

B: (482400, 1288296, 830) C1: (480975, 1286976, 788)– Define cellsize by X,Y,Z axis:

B: (10, 10, 2) C1: (20, 20, 2)– Calculate the number of cell by X,Y,Z axis :

– B: (242, 230, 35) C1: (253, 353, 83)  Define and create wirefill modeling

– Choose wirefill definition (Protom)– Define min and max cellsize by X,Y,Z axis– Choose wirefill modeling

13

CREATING BLOCK MODEL FOR THE ORE BODIES

The parameters is used to the grade interpolation of Al2O3, silica module and ratio of grain size +1 mm of bauxite fined ore (for C1 level )

16

GRADE INTERPOLATION

Field Number DescriptionSREFNUM Search volume reference numberSMETHOD 2 Search volume method   (1 = 3D rectangle,  2 = ellipsoid)SDIST1 300 Length of axis 1, initially in X direction prior to rotationSDIST2 300 Length of axis 2, initially in Y direction prior to rotationSDIST3 50 Length of axis 3, initially in Z direction prior to rotationSANGLE1 0 First rotation angle, defining orientation of search ellipsoidSANGLE2 0 Second rotation angle, defining orientation of search ellipsoidSANGLE3 0 Third rotation angle, defining orientation of search ellipsoidSAXIS1 3 First rotation axis  (1=X axis,   2=Y axis,  3=Z axis)SAXIS2 1 Second rotation axis  (1=X axis,   2=Y axis,  3=Z axis)SAXIS3 3 Third rotation axis  (1=X axis,   2=Y axis,  3=Z axis)MINNUM1 1 Minimum number of samples for first dynamic search volumeMAXNUM1 20 Maximum number of samples for first dynamic search volumeSVOLFAC2 0 Axis multiplying factor for second dynamic search volumeMINNUM2 1 Minimum number of samples for second dynamic search volumeMAXNUM2 20 Maximum number of samples for second dynamic search volumeSVOLFAC3 0 Axis multiplying factor for third dynamic search volumeMINNUM3 1 Minimum number of samples for third dynamic search volumeMAXNUM3 20 Maximum number of samples for third dynamic search volumeOCTMETH 0 Octant definition method   (0 = do not use octants,  1 = use octants)MINOCT Minimum number of octants to be filledMINPEROC Minimum number of samples in an octantMAXPEROC Maximum number of samples in an octantMAXKEY Maximum number of samples with same key field value

17

Field Number DescriptionSREFNUM Search volume reference numberSMETHOD 2 Search volume method   (1 = 3D rectangle,  2 = ellipsoid)

SDIST1 150 Length of axis 1, initially in X direction prior to rotationSDIST2 150 Length of axis 2, initially in Y direction prior to rotationSDIST3 50 Length of axis 3, initially in Z direction prior to rotation

SANGLE1 0 First rotation angle, defining orientation of search ellipsoid

SANGLE2 0 Second rotation angle, defining orientation of search ellipsoid

SANGLE3 0 Third rotation angle, defining orientation of search ellipsoid

SAXIS1 3 First rotation axis  (1=X axis,   2=Y axis,  3=Z axis)

SAXIS2 1 Second rotation axis  (1=X axis,   2=Y axis,  3=Z axis)

SAXIS3 3 Third rotation axis  (1=X axis,   2=Y axis,  3=Z axis)

MINNUM1 1 Minimum number of samples for first dynamic search volume

MAXNUM1 20 Maximum number of samples for first dynamic search volume

SVOLFAC2 0 Axis multiplying factor for second dynamic search volume

MINNUM2 1 Minimum number of samples for second dynamic search volume

MAXNUM2 20 Maximum number of samples for second dynamic search volume

SVOLFAC3 0 Axis multiplying factor for third dynamic search volume

MINNUM3 1 Minimum number of samples for third dynamic search volume

MAXNUM3 20 Maximum number of samples for third dynamic search volume

OCTMETH 0 Octant definition method   (0 = do not use octants,  1 = use octants)MINOCT Minimum number of octants to be filled

MINPEROC Minimum number of samples in an octant

MAXPEROC Maximum number of samples in an octantMAXKEY Maximum number of samples with same key field value

The parameters is used to the grade interpolation of Al2O3, silica module and ratio of grain size +1 mm of bauxite fined ore (for B level )

GRADE INTERPOLATION

  B level reserve estimation:– Total bauxite ore volume: 7,696,097m3

– Bauxite weight unit average of all ore bodies: 1.71 (ton/m3)– Bauxite crude ore reserve: 13,160,330 ton– Al2O3 grade average in ore bodies: 47.679%– Silica module average value in ore bodies: 24.14%– Average value of ratio of grain size +1 mm: 32.94%– The fined ore reserve: 4335013 ton

  C1 level reserve estimation– Bauxite ore bodies volume: 867,180,300m3

– Bauxite weight unit average of all ore bodies : 1.71 (ton/m3)– Bauxite crude ore reserve: 148,288,300 ton– Al2O3 grade average in ore bodies : 47.57%– Silica module average value in ore bodies : 24.44%– Average value of ratio of grain size +1 mm: 34.62%– The fined ore reserve : 51,337,409 ton

THE RESULTS OF RESERVE ESTIMATION AND

REPORT

18

CONCLUSIONS

19

1. The results provide a visual view in 3D of the ore bodies in the study area.

2. The bauxite reserve estimations were done for western part of Tan Rai mine in Bao Lam district, Lam Dong province, Vietnam. It’s very helpful for designing and exploiting in the future in this area.

3. The result of this research is also a basement for management of mineral resources of the local administrative.

20