whittle introductory gold tutorial

Copyright 2009 Gemcom Software International Inc. (Gemcom).

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ProductGemcomWhittle 4.3

Table of Contents

Introduction - Gold tutorial 4

Prerequisites 4

Importing 5

Validation of Imported Model 11

Setting Pit Slopes for the Optimisation 15

Optimisation 19

Mining Tab 19

Method 1. Using range function alone 19

Method 2. Using line of best fit within a range function 20

Entering the equations into theMining tab 20

Processing Tab 22

Selling tab 23

Optimisation tab 24

Output tab 24

Operational Scenario 28

Sensitivity analysis 30

Final pit and NPV Practical Pushbacks 33

Create pushbacks 35

Congratulations 40

Introduction - Gold tutorial

Introduction - Gold tutorialThis tutorial is provided to introduce various parts of software through a worked example. For moreinformation on any part of this tutorial:

l see the relevant information in the help filel view demonstration datasets and read notes in the description tab on each nodel contact your local Gemcom office for module information or training options.

In this tutorial, we will work with a validated block model from a general mine planning package suchas Surpac, GEMS or other. This block model has been created in the format .mod and also has acorresponding .par file.

PrerequisitesYou can find these data files in <your projects folder>\tutorials\gold

l the block model training.mod.l the parameters file training.par.l the block model validation report training_rpt.txt.

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Importing

Importing

1. Open Whittle from the desktop icon or Start > All Programs > Gemcom Software > Whit-tle [ver]

2. From the project selection dialog, choose Create a new project.This will start the Project Wizard which will guide you through the import process.

3. In the Project Name field, type a name for the project.You do not need to enter any other information as all other fields on this page of theProject Wizard will fill in automatically.

Note: If you would like to save the project in a different folder, rename the projectdirectory and the working directory will be automatically updated.

4. Click Next.

5. Now selectWhittle block model, and specify the location of the .mod and .par files.The .mod and .par files can be anywhere on your network.



Importing

6. OnModel File to import click browse, and select your .mod file.By default, these files will be installed in the \projects directory of your Whittleinstallation. The Project Wizard will assume the corresponding .par file is in the samedirectory and has the same name as the .mod file.

7. If required, on Parameters File to import click browse button and select your .par file.8. Click Next.

9. Continue clicking Nextwithout entering any values until you come to the Processes page(not the Process Description page).

10. Click the Add button, to add a process.11. Edit the row renaming it toMILL.

Note: Renaming the row to MILL is important for a later stage of this tutorial.



Importing

No more information will be added until we have validated themodel. You could finishhere and create the project but in this tutorial we will continue clicking through the pagesof the Project Wizard to identify the features of the wizard and their functions.

12. Click Next to display more pages of the wizard until theNext button becomes unavail-able.



Importing

The next few pages of the Project Wizard show summary information for the gradeelement and allow editing of element names. You do not have to enter any information inthese pages.

13. Click Finish.TheDefine Element Type Codes page is displayed.



Importing

14. Click Next to display theDefine Model Dimensions page.This page allows editing of themodel summary information. You do not need to enterany information in this page.



Importing

15. Click Finish.

You have now imported themodel into theWhittle interface. A range of standard analysis nodeshave been created to guide you through themine planning process.



Validation of ImportedModel

Validation of Imported ModelFirst, we will rename the block model node so we can identify the block model – in this case, we willuse themodel dimensions.

1. In theDescription field on theDescription tab of the Block Model node, enter “10 x 20 x10”.There are already notes filled out specifying the location of the original .mod and .parfiles. You can add more notes here if required.

2. Click Accept to save the changes.

3. Click on theDimensions tab to visually check the block size and model origin.4. Click the Report tab of the Block Model node to check the totals against the validation

report from the GMP.A sample validation report from Surpac is provided in the same folder as thetraining.mod file. Its file name is training_rpt.txt.




5. Further down the report, check the Summary by bench by rocktype.6. Next wewill use the 3D Viewer as a visual check.

a. Click on the Block Model node in the project tree.b. Select Start Three-D Viewer from the icon on the toolbar.c. On the Select data to display dialog box, click OK.

Tip: By clicking the Block Model node in the project tree, you bring theblock model into the 3D viewer. Later wewill visualise different things byclicking on different nodes in the project tree.

d. In the 3D Visualiser, select the Show Topography box and the Show XZ Planebox.

e. Rotate the view by clicking and dragging themouse.f. Zoom the view by holding down the wheel button of themouse and moving

themouse forward or backward.g. Click Invert (in the lower left of the window) to give the 3D Viewer a white back-

ground.




Note: We have used an inverted view for many screen captures in thisdocument so that you will save ink if you print.

Your view should look like the following. Wewill explore the 3D viewer later.For now, it is enough to visually check themodel.

Once this is done, your model is validated!

7. Close the 3D Viewer.One final thing to do on the Block Model node is to set the units of the project to grams,because that is the unit ofmeasure of our gold element.

8. On the Formats tab, in the Element data table, choose gram from the drop down menuas shown:




9. To save your changes, click Accept.



Setting Pit Slopes for the Optimisation


1. Click theNew Slope Set node in the project tree.2. In the data pane, edit the description on theDescription tab to display Slope Case 1 - 60

degrees below level 16.3. On the Slope Type tab, select Rectangular slope regions to define the slopes.

Tip: Rock types are commonly used to specify slope angles. Alternatively, an attributecan be created in the block model and filled with integers specifying different zones basedon any data.

In the Profiles tab, wewill create two new slope profiles in addition to the default slopeprofile.

4. Us the Add Profile button to create two new profiles specifying the slope angles as:l Profile 1 - Slope 45 degrees.l Profile 2 - Slope 60 degrees.




Nowwewant to split themodel into two ‘slope regions’ and assign each of our twoprofiles to a different region.

5. Use the Add button in the Slope Regions section, to add a second slope region.6. Split the regions up using the Z value of themodel. Change the values so the following

regions are defined, then use the drop down box in the Slope Profile column to assignthe slope profile.

Region Min X Max X Min Y Max Y Min Z Max Z Slope Profile

1 1 90 1 40 16 35 Profile 1 (45.0)

2 1 90 1 40 1 15 Profile 2 (60.0)

7. Click Accept to save your work.Nowwe have entered all of the relevant information, we need to generate the slope filefor use in the optimisation. To do this, we need to “run” the analysis. Wewill use the RunTo icon.

8. If it is not highlighted, click the Slope node and then click Run To to run all the analysisdown to the selected node (slopes).

9. Click the Report tab of the Slopes node to briefly check the slope errors.Tip: Slopes are created between blocks in the block model and therefore cannot

exactly define the entered slope angle. However, normally the difference is small.




We have defined two different regions for applying our slopes, so we should see the twoprofiles listed for those regions in theMessages tab.




These slope errors are acceptable, so wewill proceed.



Optimisation Method 1. Using range function alone

Optimisation

Mining Tab

l Rename theNew Pit Shells node Base Case.

Before entering the cost information, we need to build up themining cost model. In this tutorial, wehave the following information:

l Basemining cost $1.50/tonne.l Mining cost increases 5c/10metre bench below 230RL.

There are a number of ways to represent this data. In this tutorial, we are going to use the rangefunction to enter an equation that will describe themining cost adjustment factor.

Represent mining cost varying with depth using the range function.

This function is a standard function of the form R(IZ,MCAF,level,MCAF,level) which describes themining cost adjustment factor (MCAF) between two levels.

Two methods wewill explore in this tutorial are described below.

Method 1. Using range function aloneIn Excel, build up a table showing the RL crest, RL toe, IZ (block index in Z direction ofmodel), MiningCost and MCAF (MCAF =Mining Cost/Mining Cost for mining at reference block).

Your table should look like the following example, but continue to the bottom of themodel.

RL crest RL toe IZ Mining Cost MCAF

300 290 35 1.5 1

290 280 34 1.5 1

280 270 33 1.5 1

270 260 32 1.5 1

260 250 31 1.5 1

250 240 30 1.5 1

240 230 29 1.5 1

230 220 28 1.55 1.03

220 210 27 1.6 1.07

210 200 26 1.65 1.10

200 190 25 1.7 1.13

190 180 24 1.75 1.17

180 170 23 1.8 1.20

170 160 22 1.85 1.23

160 150 21 1.9 1.27

150 140 20 1.95 1.30

What wewant to represent can be described as the following:

At the bottom of the model, use an MCAF of 1.93, then at level 2 use 1.9, then at level 3 use 1.87 andso on until at level 27 use 1.07, then at level 28 use 1.03, then at level 29 and above use a value of 1(up to the top of the model).

As an equation, you can build the range function using the format:

R(IZ,MCAF,level,MCAF,level, MCAF,level ………,level, MCAF,levelMCAF,level), for example:

R(IZ,1.93,2,1.90,3,1.87,4.............,27,1.07,28,1.03,29,1)

It is easy to build up this formula in Excel using the concatenate function.



Optimisation Method 2. Using line of best fit within a range function

For more examples using the Range function, see the Expression Button help topic in theWhittlehelp.

Method 2. Using line of best fit within a range function

1. In Excel create the table shown in method 1.2. Create line of best fit with the linear part of the table, below 230RL.3. Highlight IZ and MCAF columns (below 230RL), and insert a scattergraph.4. Right click on plotted line, choose show line equation on graph.

In other words, the line should read MCAF = -0.0333 *IZ + 1.9667 and your graph should look like theone below:

We can then use the range function and nest the line of best fit within the range function.

What wewant to represent can be described as the following:

Up to the 230RL (level 29) use the equation MCAF = -0.0333 *IZ + 1.9667, for level 29 and thereafteruse a value of 1 (up to the top of the model).

As an equation, we can express this as:R(IZ,-0.0333*IZ+1.9667,29,1)

Entering the equations into the Mining tab

1. On theMining tab, enter 1.5 for the Reference Mining Cost.2. Select Calculate under Block mining cost adjustment factors then press the function

button at the right hand side of the entry box.This will expose the expression builder.

The expression builder can be used to build expressions using a range of standardfunctions, variable, and special functions.



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Optimisation Entering the equations into theMining tab

3. Type or copy the preferred expression, for example R(IZ,-0.0333*IZ+1.97,29,1), into the expression builder dialog, then click the CheckExpression button.

4. If there are no errors, click OK in the expression builder to complete theMining tab.

Your formula should now be shown in the Block mining cost adjustment factors sectionof theMining tab.

Or




5. If the Rock-typemining CAFs are not set to 1 then set them each to 1.

6. Click Accept to accept the changes on theMining tab.When you click Accept, theData Synchronization form is shown.

7. Click Yes.This dialog box confirms that you would like to copy themining information down theproject tree to the economic analysis node. Because wewant to analyse our pitshellsusing the same criteria as was used to create them, wewill always answer yes to thisquestion in this tutorial.

Processing Tab

1. Click on the Processing tab and enter the information as shown below.The Processing Paths have used the rock types in themodel file and have been assignedto the processMILL that we specified in the import wizard.




Tip: You can use theUp and Down buttons to the right of the screen to order theprocessing paths in a logical order.

2. If you see a blank table, manually create processing paths, assigning each rocktype to theavailable process ‘MILL’ by clicking the Add button on the right hand side and enteringthe information in that dialog box.

3. Click Accept on the processing tab to save.

Selling tab

1. On the Selling tab, enter the Price to be obtained for the gold, in this case $800/oz or$25.72/gram.You can enter either value, just make sure that:

1. The units are correct for the entered price and2. You have set the element units as grams on the Formats tab of the Block

Model node.

This selling price does not include royalties. If royalties are payable, reduce the sellingprice or add a selling cost.

Note: Selling prices are scaled by the revenue factor. Selling costs are not.




Optimisation tab

1. Click Default on theOptimization tab.Wewill produce approximately 50 nested pitshells at varying prices depending on therevenue factors specified here. The revenue factors scale the entered selling price toproduce different pits that are optimal for different prices.

2. Click Accept.3. Run the optimisation using the Run To command from the toolbar icons.

Output tabBefore analysing the results, we need to check theMCAFs were applied correctly.




Then wewill examine the output pitshells visually. Click on theNew Pit Shells node and start the 3DViewer.

To visually validate theMCAFs, do the following:

1. Snap to View XZ.2. Show Data – MCAF.3. Show XZ Plane.4. Click the Info tab.5. Click Show to float the information window, position it in the top right of the viewer.




As you hover over the blocks in the visualiser, the information will be shown in theinformation window.

6. Check theMCAFs have been applied correctly.7. Examine the pitshells visually by using the check box Show Pit and scrolling up and down

using the spinner directly to the right of the pit number or using the up and down arrowson your keyboard.You might also like to view the gold grades in an XY plane whilst viewing the pitshells.

8. Change the options as shown and use the left mouse button to orbit the view.Tip: Left click to orbit, right click to pan, hold mouse wheel button down and move the

mouse forward or backward to zoom.

Note: The edge of the pit is right to the edge of themodel. In this tutorial, we willaccept this. In reality, you would either extend themodel in the GMP or use thereblocking functionality in Whittle to do the extension. For more information, see theWhittle help on Advanced Reblocking or contact your local Gemcom office for trainingoptions.

9. Click the red X in the top right to close the viewer.



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10. In the Pitshells node select theOutput tab and view the range of pits created.

We nowneed to determine the final pit and create some pushbacks for the deposit. Before going tothat stage, wewill quickly examine the sensitivities of the deposit.



OperationalScenario Entering the equations into theMining tab

Operational ScenarioThe next step is to enter financial information into theNew Operational Scenario node.

1. Select theNew Operational Scenario node.Notice that theMining, Processing and Selling tabs are identical to those on the PitShells node.

2. On the Time Costs tab, enter the following:l Capital cost for project $50million.l Discount rate 8%.

3. On the Limits tab, enter themining limit as 10,000,000 (tpa), themilling limit as 1,000,000(tpa) and change the element limit units to the project units of grams.Wemust do this even though we are not using this limit in this scenario. We also need toset the throughput factors to 1 (the zeros are caused from the .par file which has beenexported from a GMP package).



OperationalScenario Entering the equations into theMining tab

4. Accept the changes on theOperational Scenario node.You should see a Pit by Pit graph already in the project tree under theOperationalScenario node.

5. If you don’t see the Pit by Pit graph, right-click and Add a Pit by Pit graph.



Sensitivity analysis Entering the equations into theMining tab

Sensitivity analysisNote: You need to have the Advanced Analysis module to complete sensitivity analysis. If you do

not have this module, you cannot perform automatic sensitivity analysis.

Wewill examine the sensitivities of the deposit, using the revenue factor 1 pitshell – Pit # 41, to give abroad understanding of sensitivities. Later, we can examine sensitivities of specific schedules once wehave created them.

1. Add a Spider Graph node under the Operational Scenario using the right click – Addmenu.

2. In the Values to vary section of theDefinition tab, click the Add button and browse thedata selector for the following information:

3. Examine theMining, Processing, and Output Groupings from the top left hand panel ofthe Data Selector then choose the secondary grouping from the right.For example, to select themining capacity, you would select:

4. In the Values to display in output section, click Add/Edit and, in theOutput section,browse to the Discounted open pit value for Specified Case.

5. Click OK twice.




6. Click Accept.7. Run the Spider Graph node and examine the graph:




You can see that for this project, the RF 1 pit is most sensitive to the following:

1. Price of gold.2. Mining recovery.3. Metallurgical recovery for FRESHmaterial.



Final pit and NPVPracticalPushbacks Entering the equations into theMining tab

Final pit and NPV Practical PushbacksSteps wewill follow to determine the final pit and the set of NPV Practical Pushbacks are:

1. Run pit by pit graph to determine likely pushbacks.2. Run pit by pit graph again to determine final pit.3. Run NPV Practical Pushbacks to determinemineable pushbacks.

1. Go to the Pit by Pit Graph node under theNew Operational Scenario node.2. Run the pit by pit graph.

You don’t need to change anything. This graph will run an NPV analysis for each pitshellusing benchmark schedules – worst case and best case.

Tip: Best and Worst Case are benchmark schedules and are not designed to be used asrealistic mine schedules. Best case schedule is ‘onion skin’ type scheduling where eachsuccessive pitshell is mined out beforemoving to the next. Worst case scheduling issimply starting at the top bench of each pitshell and mining down. These two benchmarkschedules will give an upper and lower bound to the NPV for each pitshell.

3. Analyse the graph of the pit by pit graph output.

You can see the upper and lower NPV expectations, and the different pitshells that theyoccur at. From this graph, wewill choose a number of likely pushbacks. This will enable usto plot a specified schedule and base a final pit decision on somemore realisticpushbacks.

To get a more accurate NPV, wewill choose a set of pushbacks to work with. The first willcome from the first section of the graph (pits 1-5) then a pushback from the next section(6 – 29) then a pushback from the next tonnage jump (30-35).




For this tutorial, we will use themiddle of each section, 3, 18, 32, then use thesepushbacks to determine a likely final pit.

4. Copy the Pit by Pit Graph node by right clicking and selecting Copy Node, then paste.You could also use CTRL-C, CTRL-V (making sure the navigation tree is highlighted in blue)or the toolbar icons.

5. On the Schedule tab, enter themanual pushback definitions as below and use a fixedlead of 7 as an approximation to the final mining schedule.

6. Click the Add button on the right hand side of the Specified Case Pushback Definitionsand enter the three pushbacks, separated by commas or spaces.

7. Click Accept to accept the changes and run the Pit by Pit Graph.8. Examine the pit by pit graph, paying attention to the green line – the specified case –

which is the schedule we have defined, pushbacks 3, 18, 32with a fixed lead of 7 benchesbetween pushbacks.From this graph, we can see that pitshells 35 – 41will all deliver a similar NPVwith ourthree pushbacks.

9. Again, we will select themiddle shell, pit shell 38, as our final pit.




Create pushbacksNote: You need to have the NPV Practical Pushbacks module to perform this step. If you do not

have this module, please continue using pitshells 3,18,32 and 38.

We nowwant to ensure that we have a practical, but high value set of pushbacks selected for ourgiven final pit, pit #38. To do this, we will use the NPV Practical Pushbacks module to generate pitshells that satisfy mining width constraints but also target maximum NPV for the given pitshell.

1. Rename theNew Schedule Graph node to NPV Practical Pushbacks.2. Enter the following information on the Schedule andMining Width tabs of theNPV Prac-

tical Pushbacks node:Final pit – 38, Scheduling Algorithm – Fixed Lead 7, Pushback Definition – Auto, NumberPushbacks = 4 (3 pushbacks + final pit).

Mining Width = 40m, Override default template to allow 4 x 2 block template with atolerance of 1.




3. Now, run theNVP Practical Pushbacks node using the Run To icon and examine theresults.

Note: It might take several minutes for the system to finish processing the pushbacks.

TheOutput tab will show the schedule output information for each period. TheGraphtab will show the same information graphically as follows:




Finally, the Summary tab will display the key indicators for the schedule includingexpected NPV, and Internal Rate of Return.




Now, we can use the 3D viewer to examine the shape of our pushbacks.

4. Click on theNPV Practical Pushbacks node and then click the 3D Viewer icon.

5. Click the Revised pit shells button to visualise the pit shells.




Pushbacks 2 and 3 are very small and might be combined at design time, leaving three practicalpushbacks.



Congratulations Entering the equations into theMining tab

CongratulationsYou have now completed the introductory tutorial. This information is not designed to replace anintroductory training course given by a qualified Gemcom consultant, but it is provided todemonstrate some of the basic features of the software. There aremany more advanced analysis,scheduling and specialised modules available to develop a robust mine plan for your operation, aswell as specialised techniques that will enable you to work efficiently and effectively.

For more information, contact your local Gemcom office to discuss product modules or trainingoptions.



whittle introductory gold tutorial

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