EXTRACTION OF URANIUM AND SELECTED FISSION-PRODUCTS FROM NITRIC-ACID MEDIUM BY CERTAIN DIAMIDES

Two new symmetrical diamides, namely alkyl substituted tetrabutyladipa mide (TBuAA) and aryl substituted tetrabenzyl-adipamide (TBeAA) were u sed for extraction of uranium and selected fission products from HNO3 media. Toluene was found to be the suitable solvent for both diamides. TBuAA showed higher efficiency for uranium extraction than both TBeAA and TBP. The extraction of U(VI) was investigated by distribution mea surements and spectroscopic analysis. The extracted U(VI) species by T BuAA in toluene was suggested to be UO2(NO3)(2) . 2 TBuAA. Irradiation of TBuAA by different gamma doses (5-30 MRad) showed a slight effect on U(VI) extraction efficiency. The extraction of the elements Cs, Co( U), Eu(III), Am(III), and Zr by TBuAA in toluene was found negligible for HNO3 concentrations ranging from 0.1 to 7.0 M. Tc(VII) and U(IV) s howed a reasonable extraction especially between 3 M and 7 M HNO3 conc entrations, respectively. A method for separation of U(IV)form U(VI) w as developed using TBuAA in toluene from 1 M HNO3 solution.