Improved Leaching Kinetics of Chalcopyrite With Simultaneous Grinding and Leaching.
SME Preprint 91-134 1991 :11 pages
The U.S. Bureau of Mines has developed a process to improve the leaching kinetics of diffusion-controlled systems. The system features the Bureau-developed turbomill, an attrition grinder that scrubs the reaction product coating away from the unreacted mineral grains during leaching. The system can be continuously operated at any temperature up to the boiling point of the leaching agent. This paper describes the research on the dissolution of chalcopyrite with acidified ferric sulfate which forms a sulfur product on the unreacted chalcopyrite surface. This method is a hydrometallurgical alternative to chalcopyrite smelter technology and eliminates so2 emission problems and their associated costs. Batch testing at 90 deg c with the chalcopyrite-ferric sulfate system resulted in better than 99-pct extraction of copper. At an optimal energy consumption of 1,520 kw.H/st, 95 pct of the copper was extracted. Recent work has been directed to development of a continuous system and sx-ew treatment of the resulting pregnant liquor from the chalcopyrite- ferric sulfate leach.
SME Preprint 91-134, 1991, 11 PP.