Direct Method for Producing Scandium Metal and Scandium-Aluminium Intermetallic Compounds from the Oxides

Abstract

The electrochemical de-oxidation process, also called FFC-Cambridge process, has been proposed previously to produce reactive metals and their alloys through reduction of their metal oxides. The process works by introducing metal oxides into a molten salt bath where it is electrolysed to form metal powders offering both economic and environmental benefits over the traditional metal production methods. Within the frame of the EU-financed project SCALE (GA 730105), SINTEF is investigating the optimal parameters of the direct electrolytic reduction of Sc₂O₃ and Sc₂O₃–Al₂O₃ precursors (dross from Al-Sc alloy production), giving Sc and Al-Sc metallic powders, respectively, in a molten CaCl₂-based electrolyte at a working temperature of ca. 900 °C. The influence of the applied cathodic potential in the reduction mechanism and in the metal product has been studied.