whittleIntroductoryGoldTutorial.pdf

Copyright 2009 2009 Gemcom Gemcom Software Software Internationa Internationall Inc. (Gemcom). (Gemcom). This software software and documentation is proprietary to Gemcom and, except except where where expressly expressly provided otherwise otherwise does not form form part part of any contract. contract. Changes may be made in products or services services at any time without without notice. Gemcom Gemcom publishes publishes this this documentation documentation for for the sole use of Gemcom Gemcom lice licensee nsees. s. Without writ written ten perpermission mission you may may not sell sell reproduc reproduce, e, store store in a ret retri rieva evall system, system, or transmi transmitt any part part of the documentati umentation. on. For such permi permissi ssion, on, or to obtain obtain extra extra copies copies please please contact contact your local local Gemcom Gemcom office office or visit ww www.ge w.gemcomsoftw mcomsoftware are.com. .com. While While every every precauti precaution on has been been taken in the the preparation preparation of this manual, manual, we assume no responresponsibility sibility for errors errors or omissions. Neithe Neitherr is any liabi liabili lity ty assumed assumed for for damage resulting resulting from the use of the information contained herein. Gemcom Gemcom Software Software Interna Internatio tional nal Inc. Gemcom, Gemcom, the Gemcom Gemcom logo, combinati combinations ons thereof, thereof, and Whittle Surpac GEMS, GEMS, Minex, Minex, Gemcom Gemcom InSite InSite and PCBC are are tradem trademarks arks of Gemcom Gemcom Softw Software are InterInternational Inc. or its whollywholly-owne owned d subsidiari subsidiaries. es. Product Gemcom Gemcom Whittle 4.3

Table of Contents Introducti on Gol d tutori al P rerequisites Importi ng Validation Validation of Imp Im ported Model Setting Setting P it Slopes f or the Optimi Optim isation Opti mi sati on Mining Tab Tab Method 1. Using Using ran ran ge function function alon alone e

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M ethod . Us Using line of of be best fit within a range ffu unction Entering Enterin g the equa equattions into the M ining tab Processing Processin g Tab

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Selling tab Optimisation Optimisation tab

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Output tab

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Operati onal Scenario Sensitivity Sensitivity analysis Fi nal pi t and NPV Practi cal Pushbacks Create pushbacks Congratulations

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Introduction - Gold tutorial

Introduction - Gold tutorial This tutorial is provided to introduce various parts of software through a worked example. For more information on any part of this tutorial, l l l

see the relevant information in the help file view demonstration datasets and read notes in the description tab on each node 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 such as Surpac GEMS or other. This block model has been created in the format .mod and also has a corresponding .par file

Prerequisites You can find these data files in \tutorials\gold l l l

the block model training.mod the parameters file training.par 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] From the project selection dialog, choose Create a new project 2. This will start the Project Wizard which will guide you through the import process

3. Enter a name for the project in Project Name All the other entry boxes will be filled in, you do not need to do anything more If you would like to save the project in a different folder, just rename the Project Directory and the working directory will be automatically updated. After you have named the project click Next

Nowselect Whittle block model and specify the location of the .mod and .par files. The .mod and .par files can be anywhere on your network.

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Importing

Click the browse button on Model File to import and browse to the location of your .mod file. By default, these files will be installed in the \projects directory of your Whittle instal lation. The Project Wizard will assume the corresponding .par file is in the same directory and has the same name as the .mod file. 7. If required, click the browse button and browse to the location of the .par file Click Next

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Continue clicking Next without entering any values until you come to the Processes screen. Add a process by clicking the Add button, then edit the row to rename it to MILL (this will save us time later on)

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Importing

You can finish at this screen or the next. We will not do anything more until we have val idated the model.

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Importing

The next few screens show summary information for the grade element and allow editing of element names. You do not have to do anything in these screens. Continue clicking Next until the Define Element Type Codes screen is displayed.

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Importing

Click Next This screen allows editing of the model summary information. You do not have to do anything in this screen.

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Importing

Click Finish You have now imported the model into the Whittle interface A range of standard analysis has been created to guide you through the mine planning process.

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Validation of Imported Model

Validation of Imported Model First, we will rename the block model node so we can identify the block model in this case, we will use the model dimensions. Enter x 2 x 1 in the Description field on the Description tab of the Block Model node. There are already notes filled out specifying the location of the original .mod and .par files. You can add more notes here if required. Click Accept to save the changes

Click on the Dimensions tab to visually check the block size and model origin. Nowclick on the Report tab of the Block Model node to check our totals against the val idation report from the GMP.

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5. Further down the report, check the Summary by bench by rocktype 6. Finally use the 3D Viewer as a visual check. 7. Click on the block model node in the project tree Then select Start Three-D Viewer from the icon on the toolbar Click OK on the Select data to display dialog box. Tip Clicking the block model node in the project tree will bring the block model into the 3D viewer, later we will visualise different things by clicking on different nodes in the project tree.

10 11 12

In the 3D Visualiser, select the Show Topography box and the Show XZ Plane box. Rotate the view by left clicking and dragging the mouse Zoom the view by holding down the wheel button of the mouse and moving the mouse forward or backward. Click Invert to give the 3D Viewer a white background Note We have used an inverted view for many screen captures in this document so that you will save ink if you print.

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Your view should look like the following. We will explore the 3D viewer later. For now it is enough to visually check the model.

Once this is done your model is validated One final thing to do on the Block Model node is to set the units of the project to grams, since that is what our gold element is measured in. On the Formats tab in the Element data table, choose gram from the drop down menu as shown:

Click Accept to save your changes.

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Setting Pit Slopes for the Optimisation

Setting Pit Slopes for the Optimisation Click the New Slope Set node in the project tree. 2. In the data pane edit the description on the Description tab to display Slope Case 1 degrees below level 16 Then on the Slope Type tab, ensure Rectangular slope regions is selected to define the slopes. Tip Rocktypes are commonly used to specify slope angles. Alternatively, an attribute can be created in the block model and filled with integers specifying different zones based on any data.

In the Profiles tab, we will create two new slope profiles in addition to the default slope profile. 4. Add two new profiles by clicking the Add Profile button and specifying the slope angles as: Profile Slope 45 degrees Profile Slope 60 degrees l l

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Now we want to split the model into two ‘slope regions’ and assign each of our two profiles to a different region. 5. First add a second slope region using the Add button in the Slope Regions section. 6. Then split the regions up using the Z value of the model. Change the values so the following regions are defined, then assign the slope profile using the drop down box in the Slope Profile column: Region

Min X

Max X

Min Y

Max Y

Min Z

Max Z

Slope Profile Profile Profile

Click Accept to save your work Now we have entered all of the relevant information, we need to generate the slope file for use in the optimisation. To do this, we need to “run the analysis. We will use the Run To icon. Click the Slope node if it is not highlighted and then click Run To to run all the analysis down to the selected node (slopes).

9. Now, briefly check the slope errors by clicking the Report tab of the Slopes node. 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

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

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These slope errors are acceptable, so we will proceed.

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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 the Whittle help.

Method 2. Using line of best fit within a range function 1. 2. 3. 4.

Create table as above in Excel. Create line of best fit with linear part of table below 230RL. Highlight IZ and MCAF columns (below 230RL), Insert scattergraph. Right click on plotted line choose show line equation on graph.

In other words, the line should read MCAF = -0.0333 *IZ 1.966 and your graph should look like the one below:

We can then use the range function and nest the line of best fit within the range function: What we want 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 thereafter use a value of (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 On the Mining tab, enter .5 for the Reference Mining Cost and change the radio button to Calculate 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 standard functions, variable, and special function.

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Optimisation

Entering the equations into the Mining tab

2. 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 Check Expression button. If there are no errors, click OK in the expression builder to complete the Mining tab.

Your formula should now be shown in the Block mining cost adjustment factors section of the Mining tab.

Or

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Optimisation


4. If the Rock-type mining CAFs are not set to 1 then set them each to 1

5. Accept the changes on the Mining tab. When you click Accept the Data Synchronization form is shown.

Click Yes This dialog box confirms that you would like to copy the mining information down the project tree to the economic analysis node. Because we want to analyse our pitshells using the same criteria as was used to create them, we will always answer Yes to this dialog in this tutorial.

Processing Tab Click on the Processing tab and enter the information as shown below The Processing Paths have used the rocktypes in the model file and have been automatically filled out and assigned to the process MILL that we specified in the import wizard. Use t he Up and Down buttons to the right of the screen to order the Processing Paths in logical order.

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Optimisation


3. If you see a blank table you will have to manually create processing paths, assigning each rocktype to the available process ‘MILL by clicking the Add button on the right hand side and entering the information in that dialog box.

Click Accept on the processing tab to save.

Selling tab 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 2. The units are correct for the entered price and 3. 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 selling price or add a selling cost. Note Selling prices are scaled by the revenue factor. Selling costs are not.

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Optimisation


Optimisation tab Click Default on the Optimization tab. We will produce approximately 50 nested pitshells at varying prices depending on the revenue factors specified here. The revenue factors scale the entered selling price to produce different pits that are optimal for different prices.

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

Output tab Before analysing the results, we need to check the MCAFs were applied correctly.

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Optimisation


Then we will examine the output pitshells visually. Click on the Pitshells node and start the 3D Viewer

To visually validate the MCAFs do the following Snap to View XZ 2. Show Data – MCAF 3. Show XZ Plane Click Info tab. Click Show to float the information window position it in the top right of the viewer.

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Optimisation


As you hover over the blocks in the visualiser the information will be shown in the information window. 6. Check the MCAFs 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 arrows on 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 the model. In this tutorial we will accept this. In reality, you must either extend the model in the GMP or use the reblocking functionality in Whittle to do the extension. For more information, see the Whittle help on Reblocking or contact your local Gemcom office for training options. 9. Click the red X in the top right to exit out of the viewer Go to the Output tab of the Pitshells node and view the range of pits created.

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Optimisation


We now need to determine the final pit and create some pushbacks for the deposit but before going to that stage, we will quickly examine the sensitivities of the deposit

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Operational Scenario


Operational Scenario The next step is to enter financial information into the New Operational Scenario node. Go to the Operational Scenario node. Notice that the Mining Processing and Selling tabs are identical to those on the Pit Shells node. On the Time Costs tab, enter the following: Capital cost for project $1 million. Discount rate 8% l l

On the Limits tab, enter the mining limit as 5,000,000 (tpa) the milling limit as 1,000,000 (tpa) and change the element limit units to the project units of grams. We must do this even though we are not using this limit in this scenario. We also need to set the throughput factors to 1 (The zeros are caused from the .par file which has been exported from a GMP package).

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Operational Scenario


4. Accept the changes on the Operational Scenario node. You should see a Pit by Pit graph already in the project tree under the Operational Scenario node. Ifyou don’t see the Pit by Pit graph, right-click and Adda Pit by Pit graph.

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Sensitivity analysis


Sensitivity analysis Note 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. We will examine the sensitivities of the deposit, using the revenue factor

pitshell Pit # 41 to give a

broad understanding of sensitivities. Later, we can examine sensitivities of specific schedules once we have created them. Add a Spider Graph node under the Operational Scenario using the right click – Add menu and enter the following information: In the Values to vary section of the Definition tab, click the Add button and browse the data selector for the following information:

3. Examine the Mining, Processing, and Output Groupings from the top left hand panel of the Data S selector then choose the secondary grouping from the right, for example, to select the mining capacity, you would select:

In the Values to display in output section, click Add/Edit and browse to the Discounted open pit value (NPV). Click OK twice.

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

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You can see that for this project, the RF 1 pit is most sensitive to the following Price of gold. Mining recovery 3. Metallurgical recovery for FRESH material

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Final pit and NPV Practical Pushbacks


Final pit and NPV Practical Pushbacks Steps we will 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 determine mineable pushbacks. Go to the Pit by Pit Graph node under the New Operational Scenario node. 5. Run the pit by pit graph. You don’t need to change anything. This graph will run an NPV analysis for each pitshell using benchmark schedules – worst case and best case. Tip Best and Worst Case are benchmark schedules and are not designed to be used as realistic mine schedules. Best case schedule is ‘onion skin’ type scheduling where each successive pitshell is mined out before moving to the next. Worst case scheduling is simply starting at the top bench of each pitshell and mining down. These two benchmark schedules will give an upper and lower bound to the NPV for each pitshell 6. Analyse the graph of the pit by pit graph output.

You can see the upper and lower NPV expectations, and the different pitshells that they occur at. From this graph, we will choose a number of likely pushbacks. This will enable us to plot a specified schedule and base a final pit decision on some more realistic pushbacks. To get a more accurate NPV we will choose a set of pushbacks to work with. The first will come 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).

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For this tutorial we will use the middle of each section 3, 18 32 then use these push backs to determine a likely final pit. Copy the Pit by Pit Graph node using CTRL-C, CTRL-V (make sure the navigation tree is highlighted in blue) or use the toolbar icons or use the right-click copy node, paste On the Schedule tab, enter the manual pushback definitions as below and use a fixed lead of as an approximation to the final mining schedule. Click the Add button on the right hand side of the Specified Case Pushback Definitions and enter the three pushbacks, separated by commas or spaces.

10. Accept the changes and run to the Pit by Pit Graph. 11 Now we can 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 32 with a fixed lead of benches between pushbacks. From this graph, we can see that pitshells 35 41 will all deliver a similar NPV with our three pushbacks. 12

Again, we will select the middle shell pit shell

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as our final pit.



Create pushbacks Note 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 now want to ensure that we have a practical but high value set of pushbacks selected for our given final pit pit #38. To do this, we will use the NPV Practical Pushbacks module to generate pit shells that satisfy mining width constraints but also target maximum NPV for the given pitshell. Renamethe New Schedule Graph node to NPV Practical Pushbacks. 2. Enter the following information on the Schedule and Mining Width tabs of the NPV Practical Pushbacks node: Final pit 38 Scheduling Algorithm – Fixed Lead 7, Pushback Definition – Auto, Number Pushbacks = pushbacks + final pit) Mining Width = 40m, Override default template to allow x erance of

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block template with a tol



Now run the NVP Practical Pushbacks node using the Run To icon and examine the results. Note It might take several minutes for the system to finish processing the pushbacks. The Output tab will show the schedule output information for each period. The Graph tab will show the same information graphically:

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

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Now we can use the D viewer to examine the shape of our pushbacks. Click on the NPV Practical Pushbacks node and then click the 3D Viewer icon.

5. Choose to visualise the pitshells by clicking the RES button.

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

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whittleIntroductoryGoldTutorial.pdf

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