Production of High-Purity Mg Metal from Various MgO Resources Through a Novel Electrolytic Process Using a Cu Cathode and Vacuum Distillation

Recently, a new eco-friendly electrolytic process using a metalMetal cathode followed by vacuum distillationVacuum distillation was developed to produce high-purity Mg metalMetal from MgO. In this study, the viability of this novel Mg metalMetal production process using primary and secondary resources containing MgO as a feedstock was examined. In the electrolysis experiments, an average current of 1.44 A was applied to the electrolysis cell at 1043 K for 12.5 h using Cu cathode and graphite anode in an Ar gas atmosphere. The electrolysis yielded Mg–Cu alloys of 14.0–14.4 mass% Mg with an average cell potential of 2.43–2.67 V and current efficiency of 89.6–92.4%. Vacuum distillationVacuum distillation of the Mg alloys, obtained after the electrolysis, at 1300 K for 10 h yielded Mg metalsMetal with a purity of 99.994–99.999%. Therefore, this study demonstrated that the production of high-purity Mg metalMetal from various resources that contain MgO through the novel Mg metalMetal production process is feasible.