Treatment of a nickel-copper sulphide concentrate using bioleaching

摘要

This paper describes bioleach test work performed in continuously operated bench-scale reactor systems on a nickel-copper containing sulphide concentrate at 45 and 70°C, respectively. Optimisation of the process focused on determining the effects of process parameters such as residence time, grain size and feed solids concentration on the leach kinetics, metal extractions and performance of both the moderate thermophilic and thermophilic cultures. The results showed that nickel recoveries in excess of 96% could be achieved using moderate grain size and leach temperatures, whereas ultrafine grinding and higher temperatures were required to achieve copper extractions in excess of 93%.