Selective solvent extraction of copper from acid leaching solution of PCBs with LK-C2

Copper was extracted with LK-C2 from acid leaching solution of waste printed circuit boards.The effects of pH of aqueous solution, reaction time, concentration of LK-C2 and phase ratio(O/A) on the extraction rate were investigated.The effects of the concentration of NO3-and SO42-on the extraction rate of Cu, Fe, Zn and Sn were also studied.The results show that the extraction reaches equilibrium quickly, and with increasing equilibrium pH of the aqueous solution, the copper extraction rate greatly increases.The copper extraction rate also increases with increasing concentration of LK-C2 and O/A ratio.The optimum conditions are determined that the concentration of LK-C2 in the organic phase is 15%, the phase ratio(O/A) is 1:1, the pH value of the aqueous solution is 2.00 and the reaction time is 10 min.The concentrations of NO3-, SO42-and Cl? have no significant effects on the extraction rate of Cu, Fe, Zn and Sn.Under the optimized operating conditions, copper can be extracted effectively and the extraction rate reaches 99.78% at one stage.Using sulfuric acid solution(2.00 mol/L) as stripping agent, the stripping rate of copper reaches 97.51% afterthree series of countercurrent extracting.