Process Cut-Offs

The Process Cut-Offs tab is used to define the target cut-off grade per primary element per period. If values of zero are provided for every period, Evolution will perform cut-off grade optimisation. This means that the Evolution will choose the optimal cut-off grade for each period. Otherwise the provided values will be used.

The Force Process Ranking checkbox, when checked, forces the following to take place:

  1. Calculate the overall breakeven cut-off for all processes.

  2. Order the processes by their breakeven cut-off.

  3. Evolution will enforce the rankings.

To make it clear, let us go through a worked example. Suppose the Force Process Ranking checkbox is checked. Consider the following list of processes: Mill A, Mill B and Mill C. Evolution will now calculate the overall breakeven cut-off for each process. Suppose the values calculated are as follows:

  • Mill A — 0.8

  • Mill B — 0.65

  • Mill C — 0.4

Because the behaviour has been enforced by checking the checkbox, Evolution will ensure that Mill A will always have a cut-off greater than Mill B and Mill C, and Mill B will always have a cut-off greater than Mill C.