Rate process of the reduction leaching of manganese nodules in dilute HCl in presence of pyrite. Part 1:Dissolution behavior of iron and sulphur species during leaching

摘要

An attempt has been made to study the dissolutionbehavior of Fe(Ⅱ),Fe(Ⅲ),SO42- and release of elementalsulphur(S0) during the reduction leaching of groundmanganese nodules of the Indian Ocean origin in diluteHCl in the presence of a low grade pyrite sample. Thiscomplex leaching system proceeds basically through twoconsecutive redox reactions, namely, oxidation ofpyrite by Fe(Ⅲ) to generate Fe(Ⅱ) which subsequentlyreduces MnO2 in the nodules to produce Mn2+ in solution.The effect of various parameters such as [H+],temperature, pulp density etc. on the dissolutionbehavior of the above species have been studied and discussed.