Demand side management of a run-of-mine ore milling circuit

Increasing electricity costs coupled with lower prices for some metals such as platinum group metals require a reevaluation of the operation of grinding processes. Demand side management (DSM) has received increasing attention in the field of industrial control as an opportunity to reduce operating costs. DSM through grinding mill power load shifting is presented in this paper using model predictive control and a real-time optimizer. Simulation results indicate that mill power load shifting can potentially achieve cost reductions of $9.90 per kg of unrefined product when applied to a run-of-mine (ROM) ore milling circuit processing platinum bearing ore. DSM is however still not economically feasible when there is a demand to continuously run the milling circuit at maximum throughput.

► Power load shifting was implemented on a run-of-mine ore milling circuit model.
► A real time optimizer and model predictive controller were used.
► Operating costs can be reduced for mills running below maximum capacity.
► At 93% of maximum throughput cost reductions of $9.90 kg can be achieved.
► Power load shifting is not economically feasible when there is a demand to continuously run the milling circuit at maximum throughput.