METHOD OF EXTRACTION PROCESSING OF URANIUM-CONTAINING SOLUTIONS Russian patent published in 1998 - IPC

FIELD: nuclear fuel. SUBSTANCE: uranium is extracted from uranium- containing solutions by tributyl phosphate in hydrocarbon diluent. Extract solution is washed by nitric acid solution, and uranium is reextracted by aqueous solutions containing 60-400 g/l of urea. Urea concentration in reextraction solution and ratio of organic solution stream to reextraction solution stream (N) are chosen from the following condition: Coк

/Yoи•N > 0,9, X_н< 3,144-0,0053•Coк-0,00237•Yoи•N, where Coк is concentration of urea in reextraction solution, g/l; Yoи concentration of uranium in initial organic solution, g/l; X_H concentration of nitric acid in uranium reextraction solution, mol/l; and N as indicated above. EFFECT: increased uranium concentration in reextraction step and improved safety of process. 2 cl, 5 tbl