Gold complexes and activated carbon

Abstract

The carbon-in-pulp process for gold extraction by adsorption onto activated carbon followed by elution is described and the interaction of activated C with Au complexes reviewed. Theories involving reduction of Au(CN)2 - to Au on C and electrostatic interaction between Au(CN)2 - and positive sites on the C surface are discounted. Possible mechanisms include loading of M n+Au(CN)2 -n, chemical degradation of Au(CN)2 - to insoluble AuCN or partial reduction of Au(CN)2 - to compounds contg. Au in 0 and 1 formal oxidation states. 51 ref.-R.W.