The chemistry of the nickel-copper matte leach and its application to process control and optimisation

Abstract In 1978, a decision was taken to increase the production capacity of Rustenburg Base Metals Refiners (RBMR) by installing a new plant using a similar but more efficient process. An integral part of the new refinery design was an extensive study of leaching operations on laboratory and pilot-plant scales with the intention of defining the complex leaching chemistry in order to provide a base for the development of better process control. The evaluation of chemical and mineralogical changes during the leach allowed proposal of the most likely chemical reactions taking place in the individual leaching stages. This paper discusses the proposed chemistry and its importance for the attainment of high metal recoveries and efficient metal separation.