Electro-oxidation of molybdenum concentrate in sodium chloride solution

Dissolution behavior of molybdenum concentrate by electro-oxidation has been investigated in acidic and alkaline condition at constant current density of 625 A/m2 (1A) and temperature (313K). The experiments on electro-oxidation of molybdenum concentrate obtained from Erdenet mine from Mongolia were carried out in an laboratory scale electrolysis cell with 10 mass % NaCl electrolyte. The overall current efficiency for MoS2 dissolution was 97 % in alkaline and 92 % in acidic solution after 6 hours electrolysis, respectively. The current effeciency decreased to 82 % when the electodes were not separated from the slurry. It has been shown that the dissolution of MoS2 proceeds mainly by electrochemically produced oxychlorites in the solution. The residue obtained in acidic solution consisted of Si and Al, and that in alkaline solution consisted of Si, Al, Cu and Fe. In alkaline solution, Cu and Fe, which are main impurities of the concentrate, are separated by precipitation from leaching solution.