Liquid-Liquid Extraction of V(IV) from Sulphate Medium by Cyanex 301 Dissolved in Kerosene

Abstract

The equilibrium of extraction of V(IV) in the V(IV)- SO42- (H+, Na+)-Cyanex 301 (HA)-kerosene system has been studied. Significant extraction occurs above pH 1 within 10 min. CD (extraction ratio at constant pH(eq) and [HA](o,eq)) value is slightly decreased with increasing [V(IV)](ini). CD is found to be directly proportional to [H+]-n (n ≤ 2), [HA] 2 and (1+1.58 [SO42-]). The process is endothermic (DH = 16 kJ/mol). Apparent Kexvalues at 303 K are 10-1.419 and 10-0.94 in 0.10 and 1.50 mol/L SO42- medium, respectively. The loading capacity is calculated to be7.87 gV(IV) per100 g Cyanex 301. Kerosene appears as the best diluent. Stripping to the extents of 100%, 94% and 97.7% are possible in single stage by 1 mol/L H2SO4, HCl and HNO3, respectively. Separations of V(IV) from Cu(II) (at pH 0), Zn(II) (at pH 0.5) and Fe(III) (at pH 1.0) by Cyanex 301 are possible.