Electrorefining in molten halides - comparison of the method's advantages and restrictions for high-purity rare-earth metals and scandium production

In the survey the methods are briefly described which are traditionally used for the high purity rare earth metals and scandium production. They are vacuum aremelting, vacuum distillation and sublimation, zone melting solid state electrotransport and field freezing. The opportunities of the electrorefining in molten halides for this purpose are also presented. Comparison of advantages and restrictions of the methods considered have shown the great compatibility of the electrolytical refining. 82 refs.; 6 tabs