Extraction of Lutetium with Solutions of 2-Ethylhexyl Hydrogen 2-Ethylhexylphosphonate in Hexane from Nitric Acid Solutions Containing Ytterbium
摘要
The extraction of lutetium with 0.5–2 M solutions of 2-ethylhexyl hydrogen 2-ethylhexylphosphonate (HEH[EHP]) in hexane from 0.5–2 M solutions of nitric acid containing ytterbium at a lutetium concentration of 0.57 mM (0.1 g/L) and lutetium to ytterbium concentration ratios from 1 : 1 to 1 : 50 was studied. The extraction mechanisms of both lanthanides are identical under the conditions studied. The effect of excess ytterbium on the distribution of lutetium during extraction is due to a decrease in the concentration of the free extractant. A model describing the dependence of the lutetium distribution ratio on the ytterbium concentration in the aqueous phase at various concentrations of the extractant and nitric acid is proposed; it satisfactorily agrees with the experimental data.