1. Presented by: Dr. Nguyen Thanh Long Presentation BAUXITE BLOCK MODELING AND RESERVE ESTIMATION FOR THE WESTERN PART OF TAN RAI MINE MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT

2. INTRODUCTION BAUXITE RESERVE ESTIMATIONS AND RESULTS FOR WESTERN PART OF TAN RAI MINE IN BAO LAM DISTRICT, LAM DONG PROVINCE, VIETNAM CONCLUSIONS CONTENTS 1

3.  Tan Rai bauxite mine, about 42 km 2, 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: 11 0 38’08’’ - 11 0 41’56’’ N 107 0 49’54’’ - 107 0 53’12’’ E  In this research, the western part of Tan Rai mining is concentrated for bauxite ore modeling and reserve estimation. INTRODUCTION 2

4. –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 drillholes C1: 553 drillholes

5. 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: Al 2 O 3 volume in fined ore  40% - ratio of grain size +1 mm  20%. - Silica module ( Al 2 O 3 /SiO 2 ) for the fined ore  7.0 The thickness of industrial ore is at least 1.0 m INTRODUCTION 4

6. 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

7. collars.txtX, Y, Z coordinates of the drillhole collars surveys.txtDownhole measurements of drillhole azimuth and inclination assays.txtMineral assays of drillhole samples geology.txtDrillhole sample lithology logs point.txtInformation about terrain surface: rivers, roads, contour, etc… DATA PREPARATION 6  Principle data in Datamine  Data structure of collars, surveys, assays, geology, and point files Collars Geolog y Surveys Assays

8. 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

9. 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

10. 9 CREATING STRINGS OF ALL ORE BODIES (B LEVEL) IN PARALLEL SECTIONS (35-45) Profile 35 Profile 36 Profile 37 Profile 38 Profile 39 Profile 40 Profile 41 Profile 42 Profile 43 Profile 44 Profile 45

11. 10 CREATING STRINGS OF ALL ORE BODIES (C1 LEVEL) IN PARALLEL SECTIONS (1-69) Profile 1 Profile 3 Profile 5 Profile 7 Profile 9 Profile 11

12. 11 LINKING STRINGS IN PARALLEL SECTIONS TO CREATE THE BLANK WIREFRAME (C1 LEVEL)

13. 12 LINKING STRINGS IN PARALLEL SECTIONS TO CREATE THE BLANK WIREFRAME (B LEVEL)

14. 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

15. 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 FieldNumberDescription SREFNUMSearch volume reference number SMETHOD2Search volume method (1 = 3D rectangle, 2 = ellipsoid) SDIST1300Length of axis 1, initially in X direction prior to rotation SDIST2300Length of axis 2, initially in Y direction prior to rotation SDIST350Length of axis 3, initially in Z direction prior to rotation SANGLE10First rotation angle, defining orientation of search ellipsoid SANGLE20Second rotation angle, defining orientation of search ellipsoid SANGLE30Third rotation angle, defining orientation of search ellipsoid SAXIS13First rotation axis (1=X axis, 2=Y axis, 3=Z axis) SAXIS21Second rotation axis (1=X axis, 2=Y axis, 3=Z axis) SAXIS33Third rotation axis (1=X axis, 2=Y axis, 3=Z axis) MINNUM11Minimum number of samples for first dynamic search volume MAXNUM120Maximum number of samples for first dynamic search volume SVOLFAC20Axis multiplying factor for second dynamic search volume MINNUM21Minimum number of samples for second dynamic search volume MAXNUM220Maximum number of samples for second dynamic search volume SVOLFAC30Axis multiplying factor for third dynamic search volume MINNUM31Minimum number of samples for third dynamic search volume MAXNUM320Maximum number of samples for third dynamic search volume OCTMETH0Octant definition method (0 = do not use octants, 1 = use octants) MINOCTMinimum number of octants to be filled MINPEROCMinimum number of samples in an octant MAXPEROCMaximum number of samples in an octant MAXKEYMaximum number of samples with same key field value

16. 17 FieldNumberDescription SREFNUMSearch volume reference number SMETHOD2Search volume method (1 = 3D rectangle, 2 = ellipsoid) SDIST1150Length of axis 1, initially in X direction prior to rotation SDIST2150Length of axis 2, initially in Y direction prior to rotation SDIST350Length of axis 3, initially in Z direction prior to rotation SANGLE10First rotation angle, defining orientation of search ellipsoid SANGLE20Second rotation angle, defining orientation of search ellipsoid SANGLE30Third rotation angle, defining orientation of search ellipsoid SAXIS13First rotation axis (1=X axis, 2=Y axis, 3=Z axis) SAXIS21Second rotation axis (1=X axis, 2=Y axis, 3=Z axis) SAXIS33Third rotation axis (1=X axis, 2=Y axis, 3=Z axis) MINNUM11Minimum number of samples for first dynamic search volume MAXNUM120Maximum number of samples for first dynamic search volume SVOLFAC20Axis multiplying factor for second dynamic search volume MINNUM21Minimum number of samples for second dynamic search volume MAXNUM220Maximum number of samples for second dynamic search volume SVOLFAC30Axis multiplying factor for third dynamic search volume MINNUM31Minimum number of samples for third dynamic search volume MAXNUM320Maximum number of samples for third dynamic search volume OCTMETH0Octant definition method (0 = do not use octants, 1 = use octants) MINOCTMinimum number of octants to be filled MINPEROCMinimum number of samples in an octant MAXPEROCMaximum number of samples in an octant MAXKEYMaximum 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

17. B level reserve estimation: –Total bauxite ore volume: 7,696,097m 3 –Bauxite weight unit average of all ore bodies: 1.71 (ton/m 3 ) –Bauxite crude ore reserve: 13,160,330 ton –Al 2 O 3 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: 867,180,300m 3 –Bauxite weight unit average of all ore bodies : 1.71 (ton/m 3 ) –Bauxite crude ore reserve: 148,288,300 ton –Al 2 O 3 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

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.

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