Comparative study of the extraction of V(V) and V(IV) from hydrochloric acid solutions with D1(2 ethylhexyl) phosphoric acid

Abstract

This study compared the extraction of V(V) and V(IV) from HCl solutions by di(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in n-hexane with that of tri-n-butyl phosphate (TBP) extractant reported  recently. The percentage vanadium extraction (E%) reached optimal levels of 78.0 and 83.3% for V(V)  andV(IV) respectively, at optimum pHs of 1.3 and 2.0 in that order. The extraction of both species was found to increase with D2EHPA concentration up to experimental log [D2EHPA] = -0.06 mol dm (i.e. 0.86 mol dm ). The extraction of V(V) occurred through an exothermic process at the temperature range  301-321 K and V(IV) followed a similar order. From the method of slope analysis, UV visible and infrared spectra measurements, the stoichometries of the extracted V(V) and V(IV) specieswere formulated asVO HR andVO(HR )  respectively. The study showed that V(IV) was adjudged to be better extracted than V(V) by D2EHPA under the prevailing experimental conditions.

Keywords:Vanadium, Solvent Extraction,D2EHPA; Stoichometries.