Applications of mixed potential model in leaching of gold
(Department of Mineral Engineering, Central South University of Technology, Changsha 410083,P.R. China)
Abstract: Mixed potential model is introduced to interpret gold leaching in solutions of complexing reagents. Methods of increasing the rate of gold leaching are illustrated in the view of mixed potential model. Solutions of cyanide and thiosulfate as gold leaching systems are under consideration. Enhancing either anodic or cathodic process may increase the current of gold dissolution and consequently the rate of gold leaching. High ligand concentration, additives such as Pb2+ , Hg2+ and ammonia enhance anodic processes, while pure oxygen and additive Cu(NH3)2+4 improve gold leaching by increasing cathodic polarization currents.
Key words: gold leaching； mixed potential； electrochemistry