| 摘要 |
943,441. Separating transplutonium elements. UNITED STATES ATOMIC ENERGY COMMISSION. Aug. 28,1961 [Nov. 25,19601, No. 30870/61. Heading G6R. Transplutonium values are recovered from an aqueous solution containing a mixture of them and rare earth values by adding to the solution at least a 9 molar concentration of lithium chloride, the pH of the solution being below 5, and then contacting the solution with a tertiary amine NR 1 R 2 R 3 where R 1 ,R 2 , and R 3 are alkyl, alkylene, aryl, or aryl-substituted alkyl or alkylene radicals. An organic diluent is preferably added to the amine. The transplutonium values are taken up into the organic phase, and after separation, may be stripped therefrom by distilled water or dilute acid. Suitable tertiary amines are tri-n-octylamine, tri-iso-octylamine, tri-laurylamine, methyl dioctylamine, N-methyl di-n-octylamine, N-lauryl di-n-butylamine, and N-benzyl dilaurylamine, and suitable organic diluents kerosene, benzene, toluene, and xylene; an aliphatic hydrocarbon diluent has an additive, e.g. a long chain alcohol, to prevent formation of a third phase. The concentration of amine in the diluent may be from 5-40% by weight and the organic phase is preferably saturated with HCl before extraction. Preferably the concentration of HCl in the aqueous phase is 0.001 to 0.2 molar. Americium-241 and curium-244 are the transplutonium values exemplified and the rare earth values are promethium- 148, cerium-144, europium-152, yttrium-91, and thulium-170. The extraction temperature may be in the range 0-55‹C., with 20‹-30‹C. being preferred. U. S. A. Specification 2, 809, 887 is referred to. |
