PROCESS FOR THE EXTRACTION OF ZINC FROM SULPHIDE CONCENTRATES

摘要

A portion of the concentrates is roasted and a portion of the resulting calcine is subjected to a neutral leaching step. Another portion of the concentrates is directly leached in an acidic medium in the presence of oxygen and under atmospheric conditions together with at least a portion of the neutral leaching residue. The zinc- and iron-rich solution resulting from acid leaching is neutralised with another portion of tha calcine, the iron is removed and the solution is reused in the neutral leaching step. The method enables a gradual increase in the capacity of an existing zinc plant in accordance with demand, while capital costs may advantageously be spread out over time.