HYDROMETALLURGICAL METHOD FOR RECOVERING ZINC IN A SULPHURIC MEDIUM FROM ZINC SULPHIDE CONCENTRATES HAVING A HIGH IRON CONTENT.

摘要

The invention is based on the recirculation of a solution containing no, or a low content of, iron, such that the final acidity conditions achieved are suitable for obtaining efficient precipitation of iron in the form of jarosite. In one embodiment, the zinc concentrate is subjected to the following steps: a. roasting of at least part of the zinc concentrate; b. neutral leaching, in which the zinc oxide is dissolved; c. acid leaching, in which the zinc ferrites are leached; d. reduction of the Fe+++ contained in the Fe++ solution by means of the addition of zinc concentrate and dilution with zinc sulphate solution originating from step (f) in order to reduce the concentration of Fe++; e. neutralisation of the acidity of the solution with calcine; f. oxidation of iron and precipitation of jarosite, free of solid contaminants, by means of the injection of oxygen or oxygen-enriched air and the addition of an alkali or a salt of Na+or NH4 +.