Extraction Recovery of Scandium and Concomitant Elements with Isoamyldialkylphosphine Oxide from Different Media

Abstract

Extraction of scandium and concomitant elements: titanium, zirconium, thorium, iron, and vanadium from solutions of hydrochloric, nitric, and sulfuric acids with mixed trialkyl phosphine oxide has been studied. It has been shown that the phosphine oxide can be used for scandium preconcentration processes. It has been found that scandium recovery from hydrochloric acid solutions is rather selective and can be performed from solutions containing at least 2 mol/L HCl. When this reagent is used for scandium recovery from nitric acid solutions, the main extracted element is thorium; scandium can be separated from iron(III) and vanadium upon extraction from sulfuric acid solutions, while separation from zirconium can be provided by back extraction with diluted sulfuric acid.