REACTIONS DURING THE OXYGEN LEACHING OF METALLIC SULFIDES IN THE CENIM LNETI PROCESS

Oxygen leaching of complex sulphides in concentrated solutions of ammonium chloride at moderate temperatures (< 130-degrees-C) is rapid, provided that dissolved copper is present. The attack of the different sulphides occurs via the Cu2+ ion, while the role of oxygen is to re-oxidize the Cu+ formed. This paper analyzes the Cu2+ ion leaching, in the absence of oxygen, of the main mineral species constituting these complex sulphides (sphalerite, chalcopyrite, galena and pyrite). The results obtained facilitate the interpretation of those obtained for the bulk concentrates in the presence of oxygen.