Computer Control of Lead/Zinc Concentrator Crushing Plant Operations of Mount ISA Mines Limited

Abstract

Mount Isa Mines Limited uses process control computers in its major process areas - namely the Lead/Zinc Concentrator, Copper Concentrator, Lead Smelter and Copper Smelter - to implement more complex control schemes. In this paper the development and implementation of the computer control system at the crushing plant of the Lead/Zinc Concentrator is discussed.There are some significant control problems associated with this plant which include variable plant operating conditions and long time delays. The approach that has been taken to overcome these problems was to develop a robust and comprehensive system which controls most of the major equipment Items, including the crude ore bin feeding system, the primary and secondary crushing, their associated storage and feeding systems.The control scheme is centred on dynamically compensated controllers of ore throughput and crusher power draft. To achieve maximum robustness, directed logic schemes which monitor the status of the different sections of the plant and make decisions on how to control the rest of the plant were incorporated into the control system. The control system has been able to handle the most common plant upset conditions as well as provide improved performance under steady running conditions.