Processing of bulk copper-nickel sulfide concentrates by electrothermal smelting and matte leaching

Abstract

The sulphide mineral of nickel is always associated with copper' and hence any treatment given to the mineral should aim at the recovery of both these metals. Although a number of processes involving direct leachng of sulphide concentrates using ferric chlorides, sulhuric acid2, nitric acic13,4, ammoniac etc, are being eveloped at various places, these processes involve either high pressures or pose problems of materials of construction. Pyrometallurgical processing of the copper-nickel sulphide concentrates results in high grade matte which can be further processed more conveniently and requires lesser quantity of material for subsequent treatments. In India, small tonnages of copper-nickel sulphide concen-trates are being generated as a byproduct in the recovery of Uranium at UCIL, Jaduguda. Because of the strategic importance of nickel, work was undertaken on the pyro-cum-hydrome-Ilurgical treatment of these concentrates for the recoery of copper and nickel values involving electrotheral smelting of the concentrates followed by HCl eaching of the matte.