New Solvent Extraction Process of Nickel and Copper by D2EHPA in the Presence of Carboxylates

In the present study, for the first time, the effect of sodium acetate, sodium citrate, and the addition of sodium oxalate was investigated in the D2EHPA system for the extraction of nickel and copper. In this study, the optimum condition including pH, the concentrations of additives, and time was found according to the separation factor and the extraction efficiencies. In this regard, the best extractant/extractants or their mixtures were found. Furthermore, the slope analysis was applied to understand the mechanism of extraction. According to the results, the system containing an optimum concentration of sodium oxalate and a mixture of sodium acetate and sodium oxalate could be used to separate copper from nickel and nickel from copper, respectively.