Separation of Neodymium, Samarium, and Gadolinium by Liquid-liquid Chromatography.
Proc 8th Rare Earth Research Conf 1970 Apr; 2:788-801
Neodymium, samarium, and gadolinium were separated by a liquid- liquid chromatographic technique. Sulfuric acid was more effective than hydrochloric or nitric acid as an eluant with di(2-ethylhexyl) phosphoric acid (ehpa) as the stationary phase. Recovery of 45 percent of the neodymium as greater than 90 percent nd2o3, 84 percent of the samarium as greater than 99 percent sm2o3, and 50 percent of the gadolinium as greater than 99 percent gd2o3 was achieved. The degree of separation and the time required for the separation can be varied by changing the concentration of the eluant and the number of stages in the system. A system comprising a primary amine organic extractant and an aqueous eluant containing diethylenetriaminepentaacetic acid (dtpa) was less effective for separating the rare earths.
Proc. 8th Rare Earth Research Conf., V. 2, April 1970, PP. 788-801