Scandium Recovery from a Tantalum Waste Residue: A Status Report.
Paper in Rare Earths: Resources Sci Tech & Appl TMS PP 107- 118 :107-118
The U.S. Bureau of Mines recently identified a significant new source of scandium in an Oklahoma tantalum waste residue (approximately 0.24 pct sc). Because scandium is a strategic and critical metal which the Department of Defense has classified for special consideration, the Bureau is researching methods of recovering scandium and associated metals from this and other process residues. A variety of operating parameters were evaluated to determine the best technique for recovering scandium. Testing showed that by sulfating the residue at temperatures as low as 150 deg c for reaction times as short as 0.5 H over 94 pct of the scandium converted to a water-soluble form. Solvent extraction using dehpa selectively recovered 100 pct of the scandium from the water leach solution.
Paper in Rare Earths: Resources, Sci., Tech. & Appl. TMS, PP. 107- 118