Separation of scandium by anionic liquid-liquid extraction from sulfuric acid-ammonium sulfate medium using a high molecular weight amine

The behaviors of the rare earths, scandium, thorium, uranium(VI), zirconium and yttrium in extraction from a sulfuric acid-ammonium sulfate medium with a high molecular weight amine, Amberlite LA-2, in xylene solution have been studied, and a simple and rapid method by an anionic liquid-liquid extraction with the amine xylene solution has been investigated for the separation of scandium from the rare earths, yttrium and many other metal ions. Mutual separation of lanthanum, scandium, uranium(VI) and zirconium by the extraction method is also described. Scandium, thorium, uranium(VI) and zirconium are extracted quantitatively into the LA-2 xylene solution from 0.1M sulfuric acid-0.01M ammonium sulfate solution, while aluminum, cadmium, cobalt, copper, gallium, magnesium, manganese(II), nickel, the rare earths and yttrium are not. By the extraction from 0.1M sulfuric acid-0.01M ammonium sulfate solution, scandium can be separated completely from those non-extractable cations but incompletely from indium, iron(III) and vanadium(IV). Scandium in the LA-2 xylene solution is stripped by a back-extraction with 1M sulfuric acid along with thorium, while uranium(VI) and zirconium remain in the LA-2 xylene solution. A successive back-extraction with 5M hydrochloric acid and 10% sodium carbonate solution strips mutually zirconium and uranium(VI) from the LA-2 xylene solution. Thorium behaves like scandium.