Method for the cleaning of iron-based sulphates and hydroxide from iron bases and wastes from zinc pellets in electrolytic processes as suitable raw materials for the manufacture of iron and for the recovery of zinc in waste

摘要

Purification of residues from zinc extraction contng. basic sulphates, hydroxides, Fe and Zn ferrite comprises thermally treating the alkaline suspension so that the partial pressure of O and S and the temp. of the system Zn-Fe-So w.r.t. ZnSO4 and Fe2O3 stability are controlled, the zinc and other non ferrous metals pass into soluble sulphates the hydroxide and ferrite being transformed into oxides leaving the non-oxide as the only insoluble component permitting this to be filtered off. Avoids scrapping of high tonnages of Fe2O3 because of their high Zn content.