Adsorption of Copper Complexes on Anion Exchange Resin in Non-Ammoniacal and Ammoniacal Thiosulfate Leaching Systems

Abstract

The leaching of copper using thiosulfate reagent as an alternative reagent to cyanide has been investigated since it is almost presented in gold thiosulfate leaching. This paper addressed the investigation of adsorption of copper complexes on anion exchange resin in non-ammoniacal and ammoniacal thiosulfate leaching systems.The work provided the experimental procedures for the adsorption of copper complexes on strong based anion exchange resin in non-ammoniacal and ammoniacal resin-solution systems. The result showed that increasing ammonia in the solution resulted in the diminishing total copper complexes on the resin. As the solution pH of resin-solution systems was maintained by the ammonia solution added in the system, the same effect of ammonia on the total copper complexes on resin was also shown. Overall, non-ammoniacal resin-solution system gave much better adsorption isotherm of copper complexes on resin, and the dominant species copper complexes on the strong based anion exchange resin was expected to be Cu(S 2 O 3) 3 5− based on leaching modelling.