Leaching and Precipitation; The process of leaching (atmospheric or pressure) is the primary step in most hydrometallurgical processes. The overall recovery of the valuable species is thus directly affected by the efficiency of the leach, and optimisation of the leach parameters is therefore of critical importance.
The processes group develops and tests hydrometallurgical flow sheets for the recovery and purification of metals from solution/pulps. The principal areas of expertise include ion-exchange, solvent extraction, and electro-winning.
Mintek was one of the pioneering organisations during the heyday of uranium process development. Its involvement covered different aspects of uranium recovery, and a legacy of valuable information is still available at Mintek today. Mintek is also authorised by the National Nuclear Regulator and the Department of Minerals and Energy to possess and process radioactive/nuclear samples, and is ISO 9000 and 14001 certified.
Gold process flow sheet development and test work has always been part of MINTEK’s technology service whilst MINTEK played a prominent role in establishing the Carbon-In-Leach (CIL) and Carbon-In-Pulp (CIP) cyanidation technology, during the 1970’s to 1980’s international gold boom. Generally the grade in available gold reserves is decreasing. This trend is accompanied by a general depletion of oxidized free-milling gold reserves, coupled to an escalation in exploitation of refractory gold ore bodies. Apart from the ever increasing complexity of upgrading processes (gravity, dense media separation, flotation, etc.), the gold leach chemistry is also becoming a progressively more complicated compromise between maximizing gold recovery and suppressing leaching of undesirable ore constituents.