Binary Mixture of Tri-Octyl Amine and Cyanex 923 as Extractant for the Extraction of Zr (IV) from Acidic Chloride Medium

Abstract

The extraction of zirconium (IV) from aqueous HCl solution by binary mixture TOA and Cyanex 923 using kerosene as diluent was studied. The effect of parameters like aqueous phase acid concentration, extractant concentration, chloride ion concentration, diverse ion effect, metal loading, nature of diluents and temperature on the extraction of Zr (IV) was investigated. The percentage of extraction of Zr(IV) became 100% with 0.1 M TOA and 0.01 M Cyanex 923 from 7 M HCl and also from 4 M HCl with 0.1 M TOA and 0.02 M Cyanex 923. Benzene was found to be effective diluent for the extraction of Zr(IV) with binary mixture of TOA and Cyanex 923. The positive enthalpy change and positive entropy change in the binary extraction system show endothermic process with increase in randomness. Stripping of Zr (IV) from the loaded organic phase containing mixture of TOA (0.1 M) and Cyanex 923 (0.01 M) indicated that HNO 3 and Na 2 CO 3 are the best stripping agents.