The upper layers of copper ore deposits are easily processed using hydrometallurgical leach technology, in tandem with solvent extraction and electrowinning to produce high-purity copper metal (i.e., 99.99+ percent) for use in a wide variety of electrical & electronics applications. The most abundant copper mineral, however, is chalcopyrite (CuFeS2)—a refractory semi-conductor mineral that is found deeper in the mine. Consequently, hydrometallurgical copper producers struggle to maintain metal production during the later stages of mine development. While existing hydrometallurgical processes are able to recover up to 95 percent of copper from certain refractory minerals, these processes are complicated, energy intensive and slow. The FLSmidth ROL Process technology enables the leaching of 97 to 99 percent of copper from mineral concentrates containing as little as 5 percent copper in less than six hours; a faster and much more simple process that saves energy and significantly improves sustainability of existing mines. The process technology enables current producers to remain productive, thereby extending natural resources, jobs and utilization of existing processing infrastructure. In addition to primary metal production, the process technology more efficiently recovers metals from waste recycle streams.