Low-Temperature Pressure Leaching of Converter Matte in Sulfuric Acid Solutions

Abstract

During treatment of copper-cobalt ores with a high nickel content of one of the domestic deposits by standard technology, it is expected to obtain converter matte containing, wt.%: 60–68 Ni, 7–9 Cu, 4–6 Fe, 2–3 Co, 21–23 S. It has been established for a model sample (wt. %: 62 Ni, 7.1 Cu, 3.7 Fe, 2.2 Co, 18 S) that processing converter matte under conditions of increased oxygen pressure is much more effective than under atmospheric conditions, and this is indicated by a reduction in the duration of pressure leaching (1.3–1.5 h) compared with leaching under atmospheric conditions (4–8 h), and also indices for extraction of economic components into solution (wt. %: 67 Ni, 99 Cu, 99 Fe). Due to the use of special experiment planning programs, a more complete study is achieved for the effect of oxygen pressure and temperature on leaching nickel, and also determination of the most effective production parameters for performing the process. In view of the low copper content, flotation separation of this converter matte is ineffective. Separation of copper and nickel is accomplished by selective pressure leaching of nickel from converter matte. It is established that as a result of selective leaching of nickel from copper-nickel converter matte the initial acid concentration has a considerable effect. It is possible to extract nickel into solution at the level of 50–55% and copper and iron are concentrated in cake (concentration in final solution is mg/dm³: 0.06 Cu and 0.62 Fe). A method is proposed for processing leaching products.