Extraction of vanadium from high alkaline solution by modified quaternary ammonium salt

Solvent extraction of vanadium (V) from high alkaline solution using the modified quaternary ammonium salt as the extractant was studied. The effects of extractant concentration, DL-2-Octanol concentration, alkaline and vanadium concentration of feed, phase ratio, oscillation time and temperature on the extraction of vanadium were investigated. And the extraction distribution isotherm of vanadium was also plotted. Experimental results show that the single stage extraction rate of vanadium can reaches 80 % and the saturated loading capacity for V₂O₅can reaches 5.85 g/L under the optimal conditions of alkaline of 1.5 mol/L, vanadium concentration of 3.57 g/L, phase ratio (O/A) of 2:1, oscillation time of 8 min, room temperature, and the organic phase consists of 50 wt% Trioctadecyl Methyl Ammonium Chloride (CO₃^2-type) + 20 wt% DL-2-Octanol + 30 wt% sulfonated kerosene. After five stages counter-current test, the extraction rate of vanadium can reached 99.4 % and the concentration of V2O5 leaving in the raffinate was less than 0.05 g/L.