This article will teach you how to use the Fragmentation modelling tool in SHOTPlus.This will involve:
- Creating a boundary around a pattern to set up the fragmentation heat map;
- Creating a base case;
- Calibrating the base case with actual measured data (in this case from FRAGTrack);
- Running a fragmentation model scenario and comparing to the base case selecting specific regions of a blast to predict fragmentation for sub-regions of the blast and compare to a base case and modelled blast;
- Demonstrate the effects of moving blast holes to simulate the effect of poor drilling accuracy (in the X, Y dimension; i.e., hole collar accuracy);
- Demonstrate the ability to modify explosives loading to create a more uniform fragmentation outcome.
You will need to download the 2 files below to follow this guide.
Notes about SHOTPlus "Frag Test Demo file.spf" file:
- The file contains a single blast pattern and two material types, Granite and Diorite;
- The pattern is uniform and has a uniform hole diameter;
- The default explosive type is Fortan Advantage 10 for the Granite holes and Fortan Advantage 13 for the Diorite holes;
- Rock types are set up. This includes a Granite rock type and a Diorite rock type. These differ from material types in that the rock types contain actual rock properties, which is why for modelling, material types need to be matched with corresponding rock types.
Creating a boundary around a pattern
Note: The file already contains a pattern and a boundary that has been pre-built. This section shows how to create the boundary (meaning deleting the existing boundary first). Note that for a demonstration, it may not be necessary to show this step since it doesn’t really show any fragmentation outcomes, although, for training purposes, users should know how to create boundaries that present the fragmentation heat map data neatly.
- Open the demo file
- Select the boundary, and delete it
- Go to the Tools menu, then General Functions, then Mark Clearance Zone
- Select All Holes and then enter a clearance zone radius. As a guide, use half of the spacing (in this case 3.0m)
- Select the outer edge boundary and double click to edit the boundary. Change the layer to Blast bounds and hit Ok.
- Select one of the triangles between holes. Right mouse click and Select Exact. This will highlight all of these triangles. Then delete them. You have now established a boundary for the fragmentation heat map.
Creating a Base Case
Note: A Base Case is completely separate to the blast that has been designed in the SHOTPlus file. As such, there is no fragmentation heat mapping of the base case. The purpose of the base case is for a user to establish a conventional baseline blast design and to predict a fragmentation curve for that blast. The blast that is designed in this SHOTPlus file can subsequently be compared to this fragmentation curve.
- Select the Calculations menu, and then Fragmentation Prediction. The default view opens a window that shows the Fragmentation heat map for the blast designed in SHOTPlus. Advise that we will ignore this for the moment as we first want to establish a base case against which we wish to compare our SHOTPlus blast design.
- Select the Base case setup data menu at the upper left of the screen. This allows the user to set up a base case rock type, blast design, hole loading profile. Unlike the SHOTPlus blast design on the main screen, the base case details represent values for a standard blast where all holes are the same, rather than a specific blast with differences between holes. Note the default design, in this case, is the same pattern but with Fortan Advantage 11.
- Select the Rock in the geology section. You may select Granite for this instance.
- Click on Rock Manager adjacent to this section to open the Rock resource manager screen. Select Granite and then select Edit. Here you can show that this is where the rock properties are established if the user knows what they are. With these rock details, the SabFrag model in SHOTPlus will calculate the fragmentation prediction. Click Ok to exit this window, and then close to exit the Rock resource manager screen to return to the Base case setup data screen.
At the bottom section of the screen, select Calculate from Rock Properties, and then click the button immediately below titled Calculate from Rock. This predicts the fragmentation based on the entered rock properties and produces the curve on the right-hand side.
Run the mouse pointer over the curve showing that at any point on the curve you can see mech size and % passing. If a user is interested in fines, in particular, a better view would be seen by clicking on the Graphing Mode drop-down box just above the graph and selecting the log/linear graph.
If there is no available actual fragmentation measurement data at the mine, this prediction would be the only way to start. Note, though, that most mines do not know all of the rock and structural properties very well. It is highly recommended to undertake some fragmentation measurements and calibrate the results. Years of experience in Orica has shown that calibrated SabFrag models based on actual field measurement data produce strong models for relative simulations. In the next section, we will show how results can readily be calibrated using FRAGTrack data from FRAGTrack shovel installations.
Calibrating the base case with actual measured data (in this case from FRAGTrack)
Note: This section will show how to obtain fragmentation data to calibrate with from FRAGTrack. If you have no access to FRAGTrack, use the accompanying Microsoft Excel with data already exported and formatted for import into SHOTPlus fragmentation modelling.
- Log in to the FRAGTrack website.
- Please select a site, ensuring it has a shovel installation. For this demonstration, we will choose the FRAGTrack Demonstration Site.
- Select the Insight icon in the left-hand side blue banner.
- In this case, the site has a shovel installation and a conveyor installation. We are interested in the shovel installation to calibrate using measured fragmentation data at the blast face.
- The calibration objective using FRAGTrack is to select data from a date range that corresponds to when the blast design in the base case was excavated. In this case, we will select a subset of data corresponding to that date range (we’ll use 1 – 4 May 2020).
- Select ‘New+’ to the right of the installation selection menu bar. This opens a window that prompts the user to enter a name for the Insight filter being created. Enter a title and select Save.
- A new Insight is now created; it is necessary to create a filter for the data subset required. This is done using the ‘Add Filter+’ button to open a Create New Filter box.
- Enter a name for the filter title. Select a date range. The menu options allow a date range defined in days to the present day via ‘Date Input’ or a specified date range via the selection of ‘Date Range’. Select the date range by specifying the start and end dates. If necessary, a specific time of day can be chosen to refine the date range further. The relevant shovel installation is then chosen via the drop-down selection list for Installations. Then select Save to create the filter.
- Select ‘Export Insight’ on the top right-hand side of the screen. This will create a Microsoft Excel download file (.xlsx extension).
- Open the downloaded Excel file. In the first tab, there are five columns of data. This file needs to be edited in Excel to format it for SHOTPlus to import it directly.
- Delete columns B (% in Bin), E (Cumulative Area) and F (Installation), leaving only two adjacent columns with the bin size in millimetres and the cumulative % passing percentage value. Delete rows 1 to 3 inclusive, which contain the data set titles and column header titles. You should now only be left with numbers in the new columns A and B with no headers and values starting from row 1. Save the file as a .csv file.
Go back to SHOTPlus and the Base case set up data tab within the Fragmentation Prediction window (itself selected by choosing Calculations, then Fragmentation Prediction from the SHOTPlus main screen).
In the bottom section, select Calibrate from measured fragmentation data (recommended). Then immediately under it, click on the Configure Data Pairs box. This opens a Fragmentation Data window.
In the Fragmentation Data window, click on the Import button located near the centre of the window. If necessary to navigate, go to the directory where the prepared Excel FRAGTrack data file is stored. Select the file and then click Open at the bottom right-hand side of the window. (If you do not have access to FRAGTrack to perform the previous steps, import the FragTrack 2019-08-28 22_49_41 Excel file provided with the demo file).
- This will populate the Fragmentation Data window with the measured values from FRAGTrack. Click Ok to accept, and this will adjust the graph in the Base case setup data window to calibrate the base case with actual measured data.
- In the Base case setup data window, click on the Save Fragmentation Curve button in the lower centre part of the window, enter a name (e.g., Base Case), and then select the directory to save the curve file. This serves to capture the base case curve for comparative purposes.
Running a fragmentation model scenario and comparing it to the base case.
Note: In this step, we run the fragmentation prediction of the blast designed in SHOTPlus, and compare it to the calibrated base case.
- Before running the fragmentation prediction model, return to the SHOTPlus main blast design screen and select and click to edit a blast hole on the left-hand side. Show the hole has a Material Type of Granite assigned and that on the right-hand hole cross-section, the selected product is Fortan Advantage 10. Do the same with a hole on the right-hand side of the design, showing that the Material Type is Diorite and that the selected product is Fortan Advantage 13. The go back to the main blast design view.
- Select the Calculations menu, and then Fragmentation Prediction. The default view opens a window that shows the Fragmentation heat map. Show that the fragmentation value shown is the 80% passing size in mm.
- Go to the Material Types tab. This is where the Material type is matched to a Rock Type to match the rock properties to each hole in the design. Beside Granite material type, select the box, and from the drop-down menu, select Granite. Do the same for Diorite on the next row. Then click the Calculate button at the bottom right hand of the window. Return to the Results Map tab (you may note that this step has updated the fragmentation calculation).
Go to the Settings menu in the Toolbar and select Percentage Passing, and then click Apply. This will change the values to %passing 25mm (1”). Note that you can select the size for % passing). You can play with colours at this point, although the default saved colour selection is medium-light blue for coarse and light pink for fine. You can show that this is changeable in the settings, although this is more for training than a demonstration.
At the top menu row, select Results Graph. This shows a full-window view of the predicted fragmentation curve for the blast design in SHOTPlus. Note that the Graphing mode can be selected and changed to Log / Liner if preferred.
If it is desired to compare to the base case, click on the ‘+’ button in the top right-hand side of this window, and then select the Base Case curve from the directory in which you stored it in the previous section.
Selecting specific regions of a blast to predict fragmentation for sub-regions of the blast and compare to the base case and modelled blast
Note: This part of the demonstration shows that sections of a blast can be selected to show fragmentation comparisons of different parts of the blast.
- Return to the Results Map tab within the Fragmentation Prediction window.
- In the toolbar row, click on the Detail tab (this is represented by an icon that shows a coloured bar chart approx. 2/3rds of the way along the toolbar row).
- Click on any hole. The graph window will then populate with the fragmentation curve prediction for that hole.
- Next, we will show the fragmentation data for a group of holes; in this case, the Granite holes on the left side of the blast. With the pointer, click and drag on a location and then surround the Granite holes with click points making sure to cross over the start line to close the loop and select the holes. This will show the fragmentation curve for this group of holes.
- In the smaller Fragmentation result window (containing the graph), click on the Save fragmentation curve button icon on the top right-hand side next to the ‘+’ button. Enter a name for the curve (e.g., Granite holes) and click Ok. Then click Save.
- Repeat steps 4 and 5 for the Diorite holes in the right side of the blast, naming the curve ‘Diorite holes’.
- Close the Fragmentation result window (containing the curve graph) to return to the Results Map view.
- Select the results Graph tab to return to the full window graph view with the base case curve and the predicted full blast fragmentation curve.
- In the top right-hand corner of this window, click the ‘+’ button. Select the ‘Granite holes.curve’ file and then click Open. Repeat this step for the ‘Diorite holes.curve’ file. You now have four curves on one graph (Base Case, full blast, Granite holes, Diorite holes). By running the mouse along the curve, the % passing and bin size for all curves can be compared for any point on the curve.
Demonstrate the effects of moving blast holes to simulate the effect of poor drilling accuracy (in the X, Y dimension; i.e., hole collar accuracy)
Note: For this part of the demonstration, we will return to the blast design to perform edits to hole collar positions. Therefore, when running the fragmentation prediction calculation again, the Results Graph will by default only hold the curve for the blast design in SHOTPlus. Base case or other curves can be re-established by selecting them again using the ‘+’ button. For this demonstration, we will move collar positions of selected holes manually, however, this could also be achieved by importing actual collar positions from a drill file to update the design collar locations.
- If still in the Fragmentation Prediction window, close the window to return to the main SHOTPlus blast design.
- Click and drag two holes close to another (as demonstrated by moving D5 and D6 close to E6 in the demo file and image attached below). If they don’t move, go to the Layer Manager and Unlock blast holes to allow movement.
- In the top menu, select Calculations, and then select Fragmentation Prediction. You will see that the Results map heat map has not changed. It is important to remember that you must click the Calculate button on the bottom right-hand corner every time a change is made to refresh the fragmentation prediction calculation. Upon clicking Calculate, the Results Map will be updated, showing the effects of poor drilling position on fragmentation in and around that group of holes.
Demonstrate the ability to modify explosives loading to create a more uniform fragmentation outcome
Note: This section demonstrates one of the ways that a user can seek to optimise a blast design before sending it out for loading, in this case by modifying the explosive selection in one half of the blast to more closely match Granite and Diorite fragmentation to create more uniform fragmentation for consistent digging performance.
- If still in the Fragmentation Prediction window, click Close to exit and return to the SHOTPlus blast design. Click Undo the required number of times to return the holes moved for the previous section back to their original position.
- In the top menu, select Calculations, and then select Fragmentation Prediction. You will see that the Results map heat map has not changed. Remember that you must click the Calculate button on the bottom right-hand corner to re-calculate the fragmentation prediction. If you have been using all the demo files, you will see that there is approximately a 36mm difference in the P80 passing size between the Granite side and the Diorite side, as shown in the pasted image below. The Granite side has slightly coarser fragmentation.
- Close the Fragmentation Prediction window to return to the main SHOTPlus blast design.
- To better match fragmentation, we will increase energy in the Granite side. Select all the Granite holes and then double click to open the Edit group of holes window.
- Click Edit Loading at the bottom left-hand side of that window. In the top section, select the Bulk explosive and change it from Fortan Advantage 10 to Fortan Advantage 12. This increases density, and correspondingly, energy in the hole. Click the Apply button and then the Ok button at the bottom of the window. Then click the Apply button and the Ok button in the Edit group of holes window to complete the action. All Granite holes are now loaded with Fortan Advantage 12.
- In the top menu, select Calculations, and then select Fragmentation Prediction. You will see that the Results map heat map has not changed. Remember that you must click the Calculate button on the bottom right-hand corner to re-calculate the fragmentation prediction. If you have been using all the demo files, you will see that the difference in P80 is now approximately 4 - 6mm, which is now near-identical for the Granite and Diorite side for P80.