Separation and recovery of nickel from an actual waste solution of electroless nickel-phosphorous plating solution has been investigated, employing synergistic extraction with bis(2-ethylhexyl)phosphoric acid (D2EHPA) and nicotinic acid ester. The extractability of Ni with D2EHPA alone is low, due to suppression by phosphorous compounds coexisting in the waste solution. Effective extraction can be achieved with a synergistic extraction system, using both D2EHPA and nicotinic acid ester. By optimizing the operational conditions, satisfactory extraction and stripping of more than 95 % yield can be achieved. The present extraction – stripping processing can be successfully repeated, although a small amount of the nicotinic compound is dissolved into the aqueous solution.
2013 Japan Association of Solvent Extraction