Recovery of zinc and copper from copper smelter flue dust. Optimisation of sulphuric acid leaching.

Copper smelter flue dust is a residue, rich in zinc, originating from the pyrometallurgical process of copper, and constitutes a potential raw material for zinc production. In order to valorise this waste by hydrometallurgical processes, its leaching with sulphuric acid at constant pH is studied. Experimental conditions (temperature, pH, and pulp density) are optimised by design of experiments in order to maximise Zn and Cu extractions while minimising the leaching of Fe.