DEVELOPMENTS IN THE TREATMENT OF COPPER-ARSENIC CONCENTRATES

摘要

Treatment of copper-arsenic concentrates has in the past presented technical difficulties both in achieving acceptable copper leach recoveries and fixing the arsenic in an environmentally acceptable form. Arsenic grades in copper concentrate in excess of 0.5% As are difficult to ship globally and to place with smelters. A hydrometallurgical alternative to smelting is presented which provides high copper recoveries and stabilises the arsenic as scorodite in the residues.Ongoing testwork on the Galvanox~(TM) process at the University of British Columbia (UBC) has identified an alternative catalyst suited to leaching copper-arsenic minerals and subsequent piloting has confirmed its utility.A modified Galvanox~(TM) flowsheet comprising an atmospheric leach circuit followed by solid/liquid separation and copper SX/EW has been developed based on this work where activated carbon is used to catalyse copper-arsenic minerals and pyrite oxidation is used to heat the reactors and provide iron to precipitate the arsenic leached as scorodite. The autoclave required in the typical Galvanox~(TM) circuit is not required for this circuit configuration.Capital and operating costs for this flowsheet have been developed.