A novel nanofiltration process for the recovery of vanadium from acid leach solution

• A novel nanofiltration process for the recovery of V from stone coal was proposed.
• The concentration of vanadium in the final concentrate reached more than 30 g/L.
• The permeate stream can be recycled to leaching for totally high recovery of V.
• The optimum operation pH for the rejection of vanadium was around 6–6.5.

The effects of pH, feed concentration and operation pressure on the recovery of vanadium from acid leach solution of stone coal using nanofiltration membrane technology were investigated. The rejection and permeate flux of vanadium with two kinds of membranes in nanofiltration process were also studied. After pre-treatment of leach solution to remove calcium by the addition of sodium carbonate, the vanadium in the final concentrated solution can be up to 30 g/L from 1.429 g/L in the feed under the optimum conditions of pH 6–6.5 and operation pressure of 2069 kPa at room temperature during nanofiltration process with the rejection of vanadium more than 95%. The final concentrated solution can be directly used to produce the V2O5 by traditional method, and the permeate stream can be recycled to leaching. The conceptual flow sheet for the extraction of vanadium from acid leach solution using nanofiltration membrane has been developed.