Concentrator Tonnage and Grade Modifications

To access this screen:

  • On the Processing screen, check This method modifies tonnages and grades option and click Parameters.

The settings on this screen separate the ore sent to a Concentrator for processing into ore and waste portions. The Concentrator is the processing plant that transforms ore into high grade mineral concentrate. In your product this activity is modelled by reducing ore tonnage by a given percentage, which can be defined directly or by a formula of ore attributes.

The Concentrator can also change the grades of some elements while grades of other elements remain unchanged. The grade modifications modelled here are defined exclusively by formulae of ore attributes.

Potential effects of mineral concentration:

  • Changes to the economic cutoff grade for the mine.

  • Changes to haulage requirements (ore to plant, waste to dump).

  • Changes to the mine’s overall metal recovery and profitability.

Note: All processing parameters (costs, recoveries and so on) must be defined with respect to the modified (output) ore tonnage and grades.

If Waste Types was checked on the Economic Settings Options screen, the waste portion of the selected rock type is reported as waste. If unchecked, the waste portion is added to the total waste. T

Note: The ore portion is used and reported in all optimizations (Pit Optimization, Pushbacks and Scheduler).

To define concentrator options:

  1. Display the Concentrator Tonnage and Grade Modifications screen.

  2. Choose which method is used to reduce ore tonnage, using Ore tonnage on plant is percentage of ore on input options:

    • Defined directly as – Enter a percentage of ore attributes to reduce ore tonnage by the defined percentage.

    • Defined as a function of input grades according to formula – Define a formula of ore attributes to reduce ore tonnage by a given percentage. Click Define to display the Define Formula screen.

      Note: Define changes to Edit once the formula has been defined.

  3. Use Element grades may change options to control if, or how, the selected element changes. First, select an element grade, then choose either:

    • Grade of the selected element remains unchanged – The element grade stays the same

    • Grade of the selected element changes according to formula – Define a formula to account for the element change using the Define Formula screen. See the following activity.

      Note: Define changes to Edit once the formula has been defined.

  4. Click OK to return to the destination parameters screen.

To define a grade changing formula:

  1. Display the Concentrator Tonnage and Grade Modifications screen.

  2. Select the [element] from the menu provided.

  3. Select the Grade of the selected element changes according to formula option

  4. Click Defineto display the Define Formula screen.

  5. Define the formula and click OK. If the formula is correct it is saved and the screen closes. If the formula is incorrect the message "Incorrect formula" displays and the screen remains displayed for corrections.

    Note: Define changes to Edit once the formula has been defined.

  6. Repeat steps 1 to 5 for all elements the grades of which are modified by the Concentrator.

Related topics and activities: