ASPECTS OF ELECTROCHEMICAL REACTION MECHANIS OF MAGNETITE REDUCTIVE LEACHING IN SULFURIC ACID MEDIUM

Inevitable depletion of mineral reserves involves search for the new alternative sources of non-ferrous metals, in particular, noble metals. Chromite ores in dunite, conventionally treated as refractory materials, are considered to be a prospecting feedstock of platinum group metals. Studies were performed on platinum group metals production as by-products for low-grade dunite ore processing. Gravity-magnetic flowsheet for dunite concentration allows to extract magnetic platinum-containing concentrate with high content of magnetite and platinum-ferriferous alloys. Reductive leaching in sulfuric acid medium was considered as advanced method of refining of magnetic platinum-containing concentrate from iron. Electrochemical studies of magnetite cathode reduction in sulfuric acid medium showed that magnetite rate of solution is increasing with potential shift to cathode region under increasing solution acidity and higher temperature. Kinetics of cathode process can be determined by electrolyte parameters and catalytic impact of cations of ferrous iron formed