Recovery of Cr from vanadium-containing chromate solution with copper salt precipitation after V separation

In this work, the recovery of Cr from vanadium-containing chromate solution with copper salt precipitation after V separation is presented. It has been found that after V in the vanadium-containing chromate solution was separated, Cr can be effectively enriched by adding CuSO4. Cr in the solution was precipitated in the form of copper chromate by adding CuSO4 according to Cu/Cr mole ratio 1.7 and adjusting the pH to 5.2-6.0 at room temperature. Then the precipitate was leached with NaOH solution under pH >= 12.5 at >= 80 degrees C to obtain the solution containing Na2CrO4 and the cake of CuO. After filtration, the cake was dissolved in H2SO4 solution to form the CuSO4 solution, which was reused in Cr precipitation. Finally, the product of Na2CrO4 center dot 4H(2)O with purity 99.3% was obtained by evaporation and crystallization of the leach solution.