Extraction of Am, Some Rare Earths, and Fission Products by Dibutyl-N,N-Diethylcarbamylmethylene Phosphonate and Dibutyl-N,N-Diethylcarbamyl Phosphonate

摘要

The extraction of Am, Eu, Ce(III), Fe(III), Zr(IV), and Sr from nitric acid and nitrate solutions by tetrachloromethane solutions of dibutyl-N,N-diethylcarbamyl phosphonate and dibutyl-N,N-diethylcarbamylmethylene phosphonate was studied in dependence on a number of parameters, such as the concentration of nitric acid, salting agent, weighable amounts of rare earths in the aqueous phase, and the concentration of solvents in the organic phase The solvation of nitric acid by both phosphonates and the composition of extracted complex of nitric acid are discussed and the values of the apparent constants Ksub(H,1) and Ksub(H 2) presented. Trivalent actinides and lanthanides may be separated from Sr and, in certain ranges of the aqueous phase acidity, also from Fe and Zr. The molar ratio of the solvent and the metal in the extracted complexes of the trivalent elements was equal to 3. The unfavourable effect of acid impurities in the solvents was considered and the solubilities of both phosphonates in aqueous phases evaluated. (Atomindex citation 11:557799)