Zinc and lead extraction from Çinkur leach residues by using hydrometallurgical method

In this work, it was aimed to select and propose a feasible as well as an applicable method, or series of methods, for the extraction of zinc and lead that are present in the disposed Çinkur leach residues having 12.43 wt.% Zn, 15.51 wt.% Pb and 6.27 wt.% Fe. After determination of the components of the residue, acid leaching and brine leaching were performed to reclaim Zn and Pb sequentially. Acid leaching experiments were done for Zn extraction by controlling acid concentration, reaction duration, reaction temperature and pulp density (solid/liquid ratio) as parameters. At the optimum conditions, 150 g/L H2SO4 at 95 °C for 120 min with a pulp density of 200 g/L, 71.9% of initial Zn content was extracted. For Pb extraction, brine leaching experiments were conducted on the secondary leach residue obtained after primary H2SO4 leaching. In brine leaching trials, NaCl concentration, pulp density, reaction duration, reaction temperature and effect of HCl addition were chosen as parameters. Pb extraction up to 98.9% was attained on laboratory scale after 10 min of treatment, at 300 g/L NaCl concentration, 95 °C, pulp density (50 g/L) with 30 ml/L HCl addition.