Grade Control Reporting / 2
Table of Contents
Grade Calculation Procedure 3
Change the Working Directory 3
Generate the Drillhole File 3
Build the Model File 3
Assign SG/RD To Ore Pods 4
Setup For Grade Calculation 7
Calculate Grades 8
Grade Output 13
Grade Text 13
The Report File 13
Appendix A: CAD Files 14
Appendix B: The Macro File 15
Grade Calculation Procedure
Change the Working Directory
1. Right-click the required folder in the File Explorer Pane.
2. Select the <Set as Default Directory> menu item from the context menu (Figure 2). The default directory is shown in pink in the File Explorer Pane.
Figure 1: Selecting a working directory.
Generate the Drillhole File
The drillhole file (GOLD.DHL) is imported from the Microsoft Access database GOLD.MDB. See the Block Modelling Tutorial for information on how to create and import the database.
Build the Model File
1. Select the <File<New<Model… menu item to display the model definition property sheet.
2. Enter the name of the model only. The model dimension parameters are irrelevant to this procedure and can be left as is.
3. Select the Assays page and press the <Add… button to display the Assay dialog box (Figure 3).
Figure 3: Assigning assay parameters.
4. Fill in the dialog box as shown in Figure 3.
“Length Weighted Average” is the best algorithm for polygonal grade calculations in the 3D View Pane.
The search distance should be zero for grade calculations. When the search distance is zero the algorithm searches to 'infinity' (i.e. all samples on screen).
5. Press the OK button to return to the Assays page where you can save the model file and close the model definition property sheet.
Assign SG/RD To Ore Pods
1. Load LEVEL-492.5.SVY by dragging it from the File Explorer Pane to the 3D View Pane.
2. Select the <View<Show All Data> menu item to view all the strings in the 3D View Pane.
3. Select the <Regions<Screen Area> menu item to create a region that encompasses the screen.
4. Select the <Strings<Examine/Edit menu item to display the Change Strings In Region dialog box (Figure 4).
Figure 4: Assigning SG/RD to pods.
5. Select the check boxes next to the required line types.
6. Press the <Edit… button display the String Properties dialog box (Figure 5).
Figure 5: Changing string properties.
7. Enter the parameters as shown in Figure 5.
8. Press the OK button to return to the Change Strings In Region dialog box.
9. Press the OK button to change the values of strings with the selected line types within the region.
Setup For Grade Calculation
1. Load GOLD.DHL, LEVEL-492.5.SVY and the model file created earlier in this tutorial.
2. Select the <View<Viewing Slice<Setup and Use Plan View Slice… menu item to display the Setup Plan Slice Parameters dialog box (Figure 6).
Figure 6: Setting parameters for the plan view slice.
3. Fill in the dialog box as shown in Figure 6.
4. Press the <OK> button. The view will be adjusted so that you are looking at only the samples that intersect the bench.
5. Select the <Regions<Cancel> menu item to make sure that a region is not active.
6. Select the <Strings<Examine/Edit… menu item and click on each polygon. Examine the value of the polygons to make sure it has been updated with the RD/SG for the bench.
7. Select the <View<Show All Data> menu item.
8. Select the <Regions<Screen Area> menu item.
Calculate Grades
1. Select the Drillholes<Calculate Grades...> menu item to display the first page of the grades wizard (Figure 7).
Figure 7: Selecting grade calculation parameters.
2. Select the grade calculation method and other parameters as shown in Figure 7.
3. Press the <Next> button to display the Algorithm page (Figure 8).
Figure 8: Mapping the assays.
4. Drag assays from the model assays list and drop them on the corresponding assay in the drillhole assays list. This maps the assays so that drillhole assays use the corresponding model assay’s algorithm.
5. Press the <Next> button to display the Macro Grade Text page (Figure 9).
Figure 9: Adding macro grade text.
6. Select the check box and enter the name of the macro file as shown in Figure 9.
7. Select the first macro in the macro list and press the Edit… button to display the macro dialog box (Figure 10).
Figure 10: Editing a grade text macro.
8. Make sure that the dialog box is filled as shown in Figure 10.
The macros already available in the macro file are listed in the available macros list. You can use the ID of an available macro in your own macro text. See APPENDIX B: THE MACRO FILE for more information about the available macros and how to define them.
9. Press the OK button to return to the Macro Grade Text page.
10. Press the Next button to display the Report page (Figure 11).
Figure 11: Report file details.
11. Enter the report name and header and press the <Finish> button to display the region dialog box (Figure 12).
Figure 12: Selecting a text creation method.
12. Specify that macro grade text should be created individually.
13. Press the <OK> button to begin the calculations.
Grade Output
Grade Text
IMS will now apply the calculations defined in the macro file to calculate the grades for all the polygons in the region. The resulting text is displayed at the centroid of each ore pod (you should see a similar display to the one shown in Figure 13).
Figure 13: Ore pods with grade calculation text.
If a text object overlaps another then you can move one (or both) to produce a more aesthetic display. To move the text:
1. Select the <Text<Move> menu item.
2. Click on the required text object.
3. Click again on the new position.
4. Press the Esc key to stop moving text.
Save the current CAD file but use another name so that you do not overwrite the current CAD file.
The Report File
The report file is a comma separated (CSV) file that contains all the values assigned during the grade calculation for each ore pod. This data is best viewed in a spreadsheet such as Microsoft Excel.
Appendix A: CAD Files
Ore pods are drawn from plans at the mid elevation of benches in the 3D View Pane. In the “Gold Gulley” example:
1. Data benches are named by the floor of the bench (e.g. LEVEL-492.5.SVY).
2. The plan interpretation is derived from sections.
3. Pods are assigned a line type according to the ore type (High grade = 3, Middle grade = 2, Low grade = 1).
Appendix B: The Macro File
IMS macro files can be customized to produce the output that you want by editing the files.
To edit a macro file:
1. Right click on the macro file in the File Explorer Pane.
2. Select the <Edit…> menu item from the context menu. The macro file will be opened in the text editor assigned to it.
To change the text editor:
1. Select the <Tools<Options…> menu item to display the options property sheet.
2. Select the Editors property page.
3. Enter the path of the required editor. The default text editor is Microsoft Notepad.
Figure 1 shows the contents of the customized macro file GC_CALC.MAC which is used for grade calculations in this tutorial.
Figure 1: Macro file opened in Microsoft Notepad.
In this macro file we observe the following features:
1. There is a CUT section which is applied to assay values. In this section ‘1’ represents the first assay in the drillhole file, ‘2’ represents the second, and so on.
Values for assay 1 will be cut so that grades > 80 will be replaced by 80.
2. There is a REPORT section which specifies the format of the report text.
a. Extra keywords are provided for use in the macros:
§ AREA refers to the area of the polygon.
§ LENGTH refers to the average length of the samples.
§ SNUM referes to the string number (i.e. the string ID).
§ LTYPE refers to the line type of the string.
§ SVAL refers to the string value (i.e. RD/SG in this tutorial).
§ SUMPROD refers to the sum and product totals from drill data.
b. There are six macro defined using the keywords:
§ “1” uses the values specified in the CUT section.
§ “2” uses AREA.
§ ‘3” uses AREA x 5 to calculate the volume of a bench 5m thick.
§ “4” uses AREA x 5 x SVAL to calculate the mass of the 5m bench.
§ “5” uses SNUM.
§ “6” uses LTYPE.
SNUM is determined by the order in which you digitize the ore block and cannot be changed in the 3D View Pane. It can, however, be changed by editing the CAD file directly: simply change the ‘STRPOL’ portion of the file (note that you can move STRPOL blocks around but make sure you renumber the first number of the block as this represents the SNUM).
The macros are used by prepending the % symbol to the macro ID.
EXAMPLE
Consider a polygon with the following parameters:
ID = 3
Area = 23.6m2
Volume at the 5m bench = 23.6m2 x 5m = 118.0m3
Macro: Pod %5, Volume: %3
Result: Pod: 3, Volume: 118.0