Extraction of vanadium from chloride solution with high concentration of iron by solvent extraction using D2EHPA

Abstract

Vanadium (IV) bearing chloride solution with the Fe (II)/V (IV) mass ratio of 60 was prepared to simulate the acidic liquor by hydrochloric acid leaching of reduced vanadium-bearing titanomagnetite. Extractant of bis (2-ethylhexyl) phosphoric acid (D2EHPA) was used to extract vanadium from the solution. Under the optimal extraction conditions of equilibrium H+ concentration of 0.27–0.42mol/L, D2EHPA concentration (v/v, diluted in n-heptane) of 10%, extraction temperature of 20–25°C, equilibrium time of 60min, phase ratio (O/A) of 1:1, more than 99% of vanadium can be extracted. Loaded organic phase were stripped by dilute H2SO4 solution under the optimal stripping conditions of H2SO4 concentration of 20wt.%, phase ratio (O/A) of 10:1, stripping time of 120min, and 98% of vanadium can be stripped. The concentrations of V and Fe in the stripping solution were 13.0g/L and 3.9g/L, respectively. V2O5 products with purity of 99.2% were obtained after oxidation, precipitation and calcination. The overall separation coefficient of V and Fe was 200. Experimental results indicated that V (IV) can be also separated from other metal ions such as Mg (II), Ni (II), Zn (II), Ca (II), Al (III) and Cu (II) in the chloride solution. A flow sheet on the recovery of vanadium from vanadium-bearing chloride solution containing high concentration of iron was proposed.