Optimizing ore–waste discrimination and block sequencing through simulated annealing

• The paper attempts to solve ore–waste discrimination and sequencing problems.
• The problem is minimization of violations between rates and capacities.
• Block sequencing is first solved by CPLEX.
• This solution is submitted to SA module with ore–waste discrimination.
• The findings show that the approach can be used to generate mining schedules.

This paper attempts to solve ore–waste discrimination and block sequencing problems for given capacities through a combination of goal programming (GP) and simulated annealing (SA). The problem is firstly formulated in a goal programming form, which is expressed as the minimization of the violations between the production rates and the installed capacities under access, metal quantity and the required net present value (NPV) constraints. In the model, block sequencing is first solved by CPLEX. The violations from the capacities are allowed under a cost because actual grade and tonnage values of blocks cannot be known. The violations can be accepted to some extent because mines are planned and designed on the basis of simulated/estimated grades. This solution is then submitted to the SA module such that ore–waste discrimination is incorporated into the modeling. A case study was carried out to demonstrate the approach. The findings show that the approach gives rise to the profitability and can be used to generate mining schedules.