ABSTRACT
Separation of cobalt and nickel from sulfate media was investigated, using a extraction system of 30% 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507)+15% trioctyl/decylamine (N235)+55% sulfonated kerosene. About 41 wt% Co2+ was extracted with 1.6 wt% co-extraction of Ni2+ at O/A ratio of 2:1. Scrubbing of Ni2+ and stripping of Co2+ could be achieved from the loaded organic phase, using water and 0.05 mol/L H2SO4, respectively. Cobalt extraction percentage decreased with increasing Mg2+ concentration, but this influence was negligible as [Mg2+] < 0.1g/L. The favorable equilibrium pH was 4–4.8. A different E-pH curve was observed in the P507-N235 system compared to the saponified P507 system.
Funding
This work is financially supported by National Natural Science Foundation of China (No. 51264003), Guangxi Natural Science Foundation (No. 2014GXNSFAA118325) in China and Guangxi Key Research and Development Plan (No. AB17129011) in China.