Abstract:
Dissolution of chalcopyrite in hydrochloric acid medium in the presence of manganese dioxide (manganese ore containing pyrolusite) was studied at different temperatures, acid concentrations and mineral proportions. Chalcopyrite did not dissolve independently, but underwent oxidative dissolution in the presence of manganese dioxide, via (i) galvanic interaction, (ii) cyclic action of Fe3+/Fe2+ redox couple and (iii) chlorine gas generated by MnO2 dissolution. The extent of occurrence of these phenomena was evaluated, and the last one was observed to be the most effective. At higher solids concentration in the slurry galvanic interaction between CuFe2, and MnO2 can also be significant. Kinetics and mechanism of the process are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.