Formation of Mo Metal Powder By Electrochemical Reduction of CaMoO₄ and MoS₂ Compounds

Abstract

Molybdenum (Mo) is a transition element and improves strength, toughness, hardenability and weldability of cast iron and steel. Commercially molybdenum production involves two staged hydrogen reduction which has some disadvantages. An alternative way to produce Mo metal powder is electrochemical production process, however, molten salt electrolysis is not suitable to produce Mo powder due to its high melting point. Moreover, FFC Cambridge process is also not applicable for production of molybdenum because of Mo loss during the process. An alternative electrochemical process was searched to produce Mo metal powder in this study. CaMoO4 (calcium molybdate) and MoS2 (molybdenum disulphide) were used as raw materials for reduction process. CaMoO4 was not successfully reduced, because solubility of CaMoO4 was observed during experiments. Complete reduction of MoS2 to Mo was achieved and CaS was observed as a by-product at 750oC under argon gas flow. CaS was removed by a dilute acid washing to obtain Mo metal powder.