PERFEZIONAMENTO NEI PROCEDIMENTI DI ESTRAZIONE DEI METALLI DAI MINERALI RELATIVI IN PARTICOLARE NELLA ESTRAZIONE DELLO ZINCO DAI SUOI MINERALI

摘要

GC78 In a process according to the present invention zinc is extracted from zinc sulphide containing ores using an aqueous sulphuric acid leaching liquor containing as primary oxidising agent either hydrogen peroxide or monoperoxosulphuric acid. Preferably the leaching is effected at a temperature of at least 70.degree.C and especially from 90 to 100.degree.C. The acidity of the leach liquor is preferably maintained at below pH 1.5 and especially to produce a final pH below pH 1.0. Preferably the oxident is introduced into the leaching solution progressively, maintaining its electrochemical potential at 450 mV or higher. The invention also provides a method for preferentially leaching zinc from an ore containing both sphalente and chalcopyrite.