Heavy metals in the environment. Part V: The use of high‐copper zinc residues in the zinc chloride process and the recovery of copper as anhydrous copper(II) chloride

Abstract An investigation into the use of high‐copper zinc residues in the production of zinc chloride solution and the recovery of copper, as anhydrous copper(II) chloride, is reported. The process developed involves leaching of the high‐copper zinc residues with concentrated hydrochloric acid to dissolve the zinc content leaving a residue which has a high copper content. Any copper dissolved in the primary leach is removed by electrodeposition to give a zinc chloride solution suitable for industrial use. The solid residue from the initial leach is trated with chlorine gas to solubilise the copper present, giving a solution of copper(II) chloride. This solution is purified to remove Zn2+ and Pb2+ by anion‐exchange and Fe3+ and Al3+ by hydrolysis. The purified solution can then be converted to anhydrous copper(II) chloride with a purity of 99·6%.