Development and validation of short-term mine planning optimisation algorithms for a sublevel stoping operation with backfilling

Abstract

Mining companies desire short-term mine planning optimization since this enables them to schedule major sublevel stoping mining activities like development, drilling, extraction and backfilling. If simultaneous effort is made to reduce the grade deviation resulting from all extracted ore in a certain period, this allows it to finetune the processing operations and meet production targets.

To control the short-term grade deviation, a new mixed integer linear programming model is developed which is able to consider production control constraints. For the scheduler, an objective function is developed which considers all to-be-mined ore and produces the best schedule to reduce grade deviation from combining ore of different locations. Limitations have been set on the availability of this ore. This is necessary as scheduled work must occur in the order of natural sequential transition from development, drilling, extraction and backfilling.

A copper zinc operation is used to show that the periodical grade deviation can be controlled with the model. Furthermore, validation is done to proof the functionality of control constraints. The scheduler proofs that it can create schedules for half-year scheduling horizons and that it can create a better-optimized schedule regarding grade deviation than a model without the grade deviation considerations. The obtained schedules can be used by a planning engineer for detailed shift scheduling.