Solvent extraction separation of thorium(IV) from nitric acid with Cyanex 272

Abstract

Thorium(IV) has been quantitatively extracted from 1×10^-3 <i>M </i>nitric acid with 1×10^-3 <i>M </i>Cyan ex 272 in xylene. It has been<i> </i>stripped from the organic phase with 4 <i>M </i>hydrochloric acid and<i> </i>determined spectrophotometrically as its complex with Arsenazo(III) at 655 nm. The method developed has been applied for<i> </i>the separation of thorium(IV) from chromium(VI), vanadium(V), hafnium(IV), zirconium(IV), titanium(IV), iron(III), cobalt (II),<i> </i>calcium(II) and some rare earth elements. The applicability of the method has been checked for separation of thorium(IV) from<i> </i>associated elements in the synthetic mixtures and monazite sand.The method is simple, rapid and selective for thorium(IV) with a relative standard deviation of 0.27%.