GB1044085A - - Google Patents

Abstract

1,044,085. Separation of americium and curium. UNITED STATES ATOMIC ENERGY COMMISSION. Aug. 4, 1964 [Sept. 18, 1963], No. 31260/64. Heading G6R. Americium (Am) or curium (Cm) is separated from yttrium or lanthanide rare earth fission products in an aqueous mixture by adding an aminopolycarboxylic acid or a salt thereof and a water-soluble organic acid, and then contacting the aqueous solution with an organic solution containing a monoacidic organophosphorus compound of the formula where R2 is alkyl and R3 is is alkyl or aryl. The organic phase containing fission products is separated from the aqueous phase containing Am or Cm. A number of suitable aminopolycarboxylic acids, organic acids, and organophosphorus compounds are listed; the diluent for the organophosphorus compound may be an aromatic hydrocarbon. The aqueous phase preferably has a pH of 1À5 to 4À0. The Am or Cm is removed from the aqueous phase by a second extraction with an organic solution in which the organophosphorus compound is different or is present in higher concentration, or in which an aliphatio hydrocarbon is used as diluent, the Am or Cm being returned to aqueous solution by extraction with HNO3 or HCl; alternatively oxalic acid is added to the aqueous phase to precipitate Am and Cm as oxalates. In Example I a solution containing americium,. cerium and europium is treated with lactic acid and the sodium salt of diethylenetriamiriepentaacetic acid, and extracted with di-(2-ethylhexyl) phosphoric acid in diisopropylbenzene. In other examples, components of the organic phase are decyl hydrogen decylphosphonate, diethylbenzene, and dodecane, and the organic acid is tartaric, citric, glycolic, or malonic acid.