Recovery of copper and zinc from scrap leaded brass

Abstract

Pure electrolytic copper 99.98% has been recovered from leaded brass containing 60.02% copper, 39.30% zinc and 0.53% lead. Zinc is removed by distillation under vacuum at 1000°C and the residual metal cast into slabs to be used as anodes in electro-refining. The present investigation is confined to the recovery of copper and zinc of high purity from unserviceable leaded brass by partial removal of zinc by distillation under vacuum and subsequent electrolysis. Using the residual metal as anode, copper has first been deposited electrolytically at a current density of 2.16 amp/dm2 from an acid copper sulphate solution. From the acid solution electronegative metals like zinc and lead did not deposit. Lead remained in the anode slime as lead sulphate. After complete dissolution of the anode, copper was recovered from the bath using insoluble lead anodes. After complete removal of copper, zinc sulphate was left in the solution and it was purified and crystallised.