Selective extraction of copper from acidic zinc sulfate leach solution using LIX 622

Abstract

A study has been carried out on the use of solvent extraction to remove copper from concentrated zinc sulfate leach solution. In a series of experiments using a plant leach solution containing 2 g/l Cu, 2 g/l Fe, 173 g/l Zn, 7.9 g/l H 2SO 4, 250 mg/l Cd, 15 mg/l Co and LIX 622 in SX-1, up to 97–98% of the copper present in the zinc sulfate leach solution was extracted with negligible co-extraction of zinc, iron, cadmium and cobalt. The selectivity of copper over other metals in solution was very high. Copper was extracted selectively from solution at relatively low pH values and the process did not require any pH modification. The copper-loaded organic was almost completely stripped using 150 g/l sulfuric acid solution.