Synthesis of Cu(II) ion-imprinted polymers as solid phase adsorbents for deep removal of copper from concentrated zinc sulfate solution

Abstract

Novel copper (II) ion imprinted polymers (Cu(II)-IIPs) were designed and synthesized as solid phase absorbents for the selective deep removal of Cu2+ from concentrated zinc sulfate solution. Salicylaldoximes, used as chelating ligands, were anchored onto the polymer networks through quaternary ammonium cation spacers. The effect of pH, temperature, contact time, and swelling on the adsorption selectivity and the copper removal efficiency of Cu(II)-IIPs were investigated in a laboratory-scale cell. The results showed that the adsorption of Cu2+ increased significantly with increasing pH from 1 to 7, and increased with decreasing operation temperature. The equilibrium Cu2+ adsorption capacity of Cu(II)-IIPs from the zinc sulfate aqueous solution was 96mg·g−1 at 25°C in pH5.0 for 10min. Under optimized processing conditions, the copper removal efficiency reached 99.9%, and the concentration of the residual copper (II) ions in the purified ZnSO4 aqueous solution is 35μg·L−1, significant lower than the maximum acceptable value as 100μg·L−1 in the hydrometallurgical zinc process.