In this tip of the month, we will see how to insert a statistics report and generate a grade- tonnage curve for a block model. This is really useful to quickly analyze the properties of each grade value and to determine the optimal point of obtaining the maximum grade without decreasing the tonnage. To do so:

  1. Insert the objects to be analyzed. This can consist of blocks, samples, composites or points. In this specific example, a block model is
  2. From the Exploratory Data Analysis module, go to the module options and:
    • Select the type of objects to be analyzed
    • Configure the report format
    • Select the statistics items to be in the report using the “->” button. To remove an item, select an item and click the “<-“
    • Click OK once the parameters are
  3. Select the “Statistics” (EDAS) command, select the block model and hit Enter. A window will appear showing the grade values found in the block model. Select the option “Display units” and click OK. Place the Statistics report in the drawing. This report includes the statistics items chosen in the module
  4. Select the “Grade-Tonnage curve” (EDAGTC) command and select the block model (note that this command only works with block models). Hit Enter and configure the parameters in the window:
    • Select the grade type
    • Input a density
    • Input a minimum cut-off grade (based on the statistics report)
    • Input a maximum cut-off grade (based on the statistics report)
    • Select “Graph” to display the Grade-Tonnage graph of the selected grade
  5. The cut-off grade is on the X-axis. The tonnage above cut-off grade is on the left-hand side of the Y-axis. The average grade above cut-off grade is on the right-hand side of the Y-axis. The optimal point consists of the intersection of both curves. This point determines the maximum average grade above the cut-off grade without decreasing the tonnage. To display the exact coordinated of this point, right-click and select the “Show point values”. To save this graph as an image, right-click and select “Save Image ..”