Recent developments in aqueous processing

Abstract

More than fi fty years have elapsed since the Sherritt–Gordon ammonia pressureoxygen-leaching process for nickel sulfi de fl otation concentration was developed in the 1950s. In the intervening time, dramatic new technologies in hydrometallurgy have transpired. The application of the solvent extractants for copper in leaching-SX–EW process is now commonplace, activated carbon technology has been implanted in gold recovery processing, and heap leaching is widely used to extract copper and gold from low-grade materials. Over the last three decades hydrometallurgical processing of chalcopyrite concentrates has received considerable attention because of interests that include environmental aspects and the possibility of increased exploitation of mixedand lower-grade ores. There has been a worldwide upsurge of hydrometallurgical process interests for the production of copper. Cuprous hydrometallurgical methods of reducing chalcopyrite were well studied by A.J. Parker and colleagues in 1980. Although it was on a laboratory scale within a non-aqueous process, the remarkable fi nding of factors that affect the rate and effi ciency of chalcopyrite dissolution still has merit in today’s R&D projects. A process that also deserves merit is the in-situ mining method using a dilute sulfuric acid for a deep copper-oxide deposit was developed by the former U.S. Bureau of Mines in 1986 and could lead to future innovative and low-cost copper mining methods. Recent Developments in Aqueous Processing