Display the block model by SG Attribute
Fill the “Gold” attribute with the Inverse Distance2 estimation method 16. Use the following estimation parameters:
For QPY1.DTM ore solid
VII. Composite file = cmpq1.str VIII. Maximum search radius = 100m
IX. Maximum vertical search distance = 9999 X. Bearing of major axis = 40
XI. Plunge of major axis = 0 XII. Dip of semi-major axis = 42 XIII. Anisotropy Ratios
i. major / semi-major = 2 ii. major / minor = 10
XIV. Constraints: Inside 3DM (qpy1.dtm) XV. Ellipsoid Origin: Y:7260 X:1560 Z:900
For BIF1.DTM ore solid
XVI. Composite file = cmpb1.str XVII. Maximum search radius = 100m
XVIII. Maximum vertical search distance = 9999 XIX. Bearing of major axis = 50
XX. Plunge of major axis = 0 XXI. Dip of semi-major axis = 55 XXII. Anisotropy Ratios
i. major / semi-major = 3 ii. major / minor = 10
XXIII. Constraints: Inside 3DM (bif1.dtm) XXIV. Ellipsoid Origin: Y:7350 X:1840 Z:1000 For SAND1.DTM ore solid
XXV. Composite file = cmps1.str XXVI. Maximum search radius = 100m
XXVII. Maximum vertical search distance = 9999 XXVIII. Bearing of major axis = 27
XXIX. Plunge of major axis = 0 XXX. Dip of semi-major axis = 0 XXXI. Anisotropy Ratios
i. major / semi-major = 4 ii. major / minor = 10
XXXII. Constraints: Inside 3DM (sand1.dtm) XXXIII. Ellipsoid Origin: Y:7335 X:1760 Z:1000 Create a Block Model Report
17. Create a Block Model Report and report the following 1. Average weighted gold grade
2. Average weighted specific gravity 3. Tonnage (multiplication factor = SG) 4. Organized by bench (800,1000,10)
Files required:
USEFUL TOOLBAR ICONS
BLOCK MODELLING
Open Block Model Close Block Model Display Block Model Add New Graphical Constraint Remove Last Graphical Constraint
Remove All Graphical Constraint Edit Block Model Constraint Block Edge and Face Visibility
Add Slicing Plane Constraint Remove Slicing Plane Constraint
Colour Model by Attribute Remove Block Colours Add Block Model Attribute Delete Block Model Attribute
Edit Block Model Attribute Block Maths Identify Block Values
PROCEDURE
Open Database
1. Open the database DB1.DDB and display the drill holes – determine extents and become familiar with the dataset.
a. Open the db1.ddb and display the drill holes (DATABASE | DISPLAY | DRILLHOLES)
b. Open the topography file TOPO1.DTM
c. Plot a 2D grid (PG) and determine the minimum and maximum co-ordinates of the area.
d. The co-ordinates to adequately cover the block model would be approximately: • Northing: 7100 -7620
• Easting: 1200 - 2000 • RL: 820 -1050
2. Create an empty block model, ensuring to cover the area required totally. a. Select Block Model | New/Open
b. Enter the minimum and maximum co-ordinate as determined above and select a user block size and variable sub-celling size. The block size should reflect the drill hole spacing, mining equipment to be used and the structure of the ore.
c. Apply through the following form, if required, you can change the block size if needed.
d. The block model has now been created and the name of the block model will appear on the status bar.
e. Save the block model.
3. Export the centroid points to a string file and validate the model area.
4. Create a graphical constraint of the qpy1.dtm & bif1.dtm and validate the user block size of your new block model.
a. Select Constraints | New graphical constraint and complete the form as shown below – there is no need save this constraint.
b. Drag and drop QPY1.dtm and validate the user block size of your new block model.
c. Select Constraints | Remove all graphical constraints.
d. Select Constraints | New graphical constraint and complete the form as shown below – there is no need save this constraint.
e. Drag and drop BIF1.dtm and validate the user block size of your new block model.
f. Select Constraints | New graphical constraint and complete the form as shown below – there is no need save this constraint. Combine both the BIF1.DTM and the QPY1.DTM. Note the constraint combination (a or b).
Create Attributes
5. Add the attribute “gold” to the block model.
a. Make sure you’re connected to the block model first. From the Navigator, click and drag the block model “blockmodel.mdl” into the view port to connect to it. Notice the special icon and name of the block model that appears in the status bar.
b. From the Block Model menu, choose Attribute, New. c. Fill the subsequent form as follows:
6. Add the attribute “sg” to the block model.
a. From the Block Model menu, choose Attribute, New. b. Fill the subsequent form as follows:
7. Add the attribute “gold_cut” to the block model.
a. From the Block Model menu, choose Attribute, New. b. Fill the subsequent form as follows:
8. Add the attribute “orecat” to the block model.
a. From the Block Model menu, choose Attribute, New. b. Fill the subsequent form as follows:
View the new attributes and values created above by having the block model displayed and then selecting Attribute | View attributes for one block and then select a block.
Apply constraints to model
9. Create and save a constraint file for:
• Inside qpy1.dtm save as qpy1.con
• Inside bif1.dtm save as bif1.con
• Inside sand1.dtm save as sand1.con
• Combination of all above save as qpy_bif_sand.con
Select Block Model | Constraint | New Graphical Constraint and complete constraints for the above.
Example given below for qpy1.con constraint, repeat for bif1.dtm and sand1.dtm
Fill Block Model with SG Values
10. Fill the “sg” attribute with the Assign Value method. Assign a specific gravity of 0.00 to all blocks above the topography “topo1.dtm”.
a. From the Block Model menu, choose Estimation, Assign value. b. Fill the subsequent forms as follows:
11. Fill the “sg” attribute with the Assign Value method. Assign a specific gravity of 1.68 to all blocks below the topography “topo1.dtm” and above “weath_ew1.dtm”.
12. Fill the “sg” attribute with the Assign Value method. Assign a specific gravity of 2.11 to all blocks below “weath_ew1.dtm” and above “weath_fresh.dtm”.
13. Fill the “sg” attribute with the Assign Value method. Assign a specific gravity of 2.46 to all blocks below “weath_fresh.dtm”.
14. Fill the “sg” attribute with the Assign Value method. Assign a specific gravity of 2.9 to all blocks in the ore solid “bif1.dtm”.
Display the block model by SG Attribute
15. Remove all graphical constraints and then constrain the block model below the