Selective removal of copper from the artificial nickel electrolysis anolyte by a novel chelating resin: batch, column and mechanisms

The selective removal of copper from the artificial nickel electrolysis anolyte was presented with a novel N-octyl-2-aminomethylpyridine-funcionalized chelating resin (abbreviated as CP-AMPO) in this study. In the single system, the adsorption characters of the CP-AMPO resins for Cu2+ and Ni2+ were examined through pH of solution, concentration of metal ions, contact time and temperature. Through the experimental investigation, the isotherm adsorption behavior of Cu2+ fitted well with Langmuir isotherm, whereas the adsorption behavior of Ni2+ followed the Langmuir and the Freundlich isotherm. The kinetic adsorption parameters were proved to be in agreement with the pseudo-second kinetic model, the thermodynamics data demonstrated the adsorption behaviors of Cu2+ and Ni2+ were a spontaneous and endothermic process. Additionally, from the competitive adsorption in the binary systems, the separation factor of copper/nickel reached 2000, indicating higher selectivity for copper over nickel. Moreover, the residual concentration of copper was less than 3 mg/L at the beginning of 8 BV in the artificial nickel electrolysis anolyte after purification and the mass ratio of copper/nickel exceeded 15 in the saturated resins by the dynamic adsorption curves. The results could well satisfy the production requirement of the nickel electro-refining procedure. Therefore, the CP-AMPO resins could be used as the high-performance adsorbent to remove copper from the nickel electrolysis anolyte in the large-scale industry. Consequently, the extended study of the chelating resin on the mechanisms of selective adsorption for copper and nickel was assessed by X-ray photoelectron spectroscopy (XPS).