Separation and recovery of V(IV) from sulfuric acid solutions containing Fe(III) and Al(III) using bis(2-ethylhexyl)phosphoric acid impregnated resin

摘要

Separation and recovery of V(IV) from the synthetic sulfuric acid solutions containing Fe(III) and Al(III) were investigated using the bis(2-ethylhexyl)phosphoric acid (D2EHPA)impregnated resin (DIR). It is confirmed that D2EHPA was incorporated to the support by comparing the characteristics of the support resin and DIR using thermogravimetric analysis (TGA) and Fourier transform infrared spectra (FT-IR), respectively. Batch experiments proved that the adsorption capacity of Fe(III) on the DIR was by far higher than that of V(IV) and Al(III), and the separation factor of Fe(III) to V(IV) reached the plateau at the pH ranging from 1.0 to 1.2, which provided feasibility for the V(IV) separation from the solutions by column mode. During the preferential removal of Fe(III) by the DIR, it was shown that effective Fe(III) removal can be achieved at feed flow rate of 1.0 mL/min, column height of 18 cm and solutions pH 1.0. Subsequently, 1.5 mol/L H2SO4 and 30 g/L H2C2O4 was appropriate for the stepwise elution of partial loaded V(IV) and Fe(III), respectively. The iron-removed effluent was combined with the following eluted vanadium-bearing solutions and then was further processed by the DIR. Finally, the vanadium-rich solutions were obtained by stripping with 1.0 mol/L H2SO4. The total recovery of vanadium was 91.47% and it was concentrated almost 5 times. This study provides potential method for the separation and recovery of V(IV) from acid aqueous solutions by solvent impregnated resins. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.