Separation and recovery of sulfuric acid from acidic vanadium leaching solution by diffusion dialysis

Diffusion dialysis with anion exchange membranes was employed to recover sulfuric acid from acid leaching solution generated in vanadium producing process. The effects of flow rate, flow rate ratio, V, Al and Fe ions concentration on the recovery of H2SO4 and metal ions rejection were investigated. The results have proved that sulfuric acid permeates well through the membrane used, while the vanadium ions are efficiently rejected. Over 84% H2SO4 recovery efficiency could be achieved by controlling the flow rate of 0.21 × 10−3 m3/h m2, flow rate ratio of 1.1–1.3 at 25 °C. V, Al and Fe ions rejection could reach to 93%, 92% and 85%, respectively.

► Diffusion dialysis was used to recover H2SO4 from vanadium leaching solution.
► The factors influencing the performance of recovery process were investigated.
► The membrane is a good separator for recovery of H2SO4 and rejection of vanadium.
► The treated solution can fit the request of pH for solvent extraction of vanadium.