TREATMENT OF CHALCOPYRITE CONCENTRATES BY HYDROMETALLURGICAL TECHNIQUES

A variety of hydrometallurgical techniques have been studied for the treatment of chalcopyrite concentrates. These include prior thermal treatment before leaching, direct leaching and direct electrochemical leaching. Thermal treatment to alter the mineralogical composition of the concentrate without oxidation with oxygen has been studied. In direct leaching, a variety of leaching systems like sulphate, chloride, nitric acid, ammoniacal systems and biological systems have been investigated. Direct electrochemical leaching of chalcopyrite concentrates with a view to recover copper and elemental sulphur has been proposed. Slurry electrolysis of chalcopyrite concentrates and basic studies to elucidate the mechanism of dissolution have been done. The development of a less polluting hydrometallurgical process as an alternative to smelting is the need of the future. The avoidance of air pollution as well as economic considerations such as capital cost, operating cost and recovery of hyproducts will determine the adoption of these new processes.