Methods for Preparing Pure Scandium Oxide

A review of the tecchniques for isolating scandium in a pure state is presented, including the newest cationexchange methods. These methods include elution with ethylenediaminetetraacetate and N- hydroxyethylethylenediaminetriacetate solutions and the use of copper and lead ions, respectively, as retaining ions which permit passage of scandium but retaln rare earth ions. A new approach to opening thortveitite ore by treating with ammonium bifluoride and reducing the mixed metal fluorides to the metallic state with calcium is presented. (auth)