Research progress in intensified bioleaching of chalcopyrite: A review

Chalcopyrite (CuFeS2) as one of the most abundant copper sulfide minerals, is refractory to conventional hydrometallurgical and pyrometallurgical processes. Bioleaching is a practice of extracting valuable metals by using acidophilic bacteria to catalyse the dissolution of sulfide/iron-containing ores. It has been widely adopted in copper ores processing due to environmental and economic performance over the conventional methods, especially its use in low-grade sulfide minerals. To date, low copper extraction is a common problem during chalcopyrite bioleaching, which limits its industrial application. Hence, it is of particular importance to find methods to enhance the leaching rate. Chalcopyrite dissolution is a complex process with the participation of microorganisms, minerals and gas and liquid phases. All these physicochemical, microbiological, mineralogical and processing parameters have influences on the rate and efficiency at which bioleaching proceeds. High copper yield can be achieved by optimizing leaching conditions in an optimum range. A number of researches has been conducted to explore the influence of leaching parameters on bioleaching rate. This review intends to briefly describe the effect of some parameters on the bioleaching of chalcopyrite. And it lays the emphasis on the presentation of methods to promote the efficiency of bioleaching and the strengthening mechanisms.