Thermochemical review of jarosite and goethite stability regions at 25 and 95°C

The hydrometallurgical treatment of zinc sulfide concentrates involves the separation of zinc from iron, since most zinc concentrates contain 5-12% iron. Several processes, such as hematite, magnetite, goethite and jarosite, have been developed for the removal of iron from solution prior to zinc electrolysis. The precipitation of iron is controlled by a set of thermodynamic and kinetic factors operative both in iron solutions and in precipitates. Identifying these factors and their relations is important for the control of these processes. Inbrief, thermodynamic stability regions of iron compounds formed during the jarosite and goethite processes, which are commercially used in the zinc industry, are outlined in this paper.