STUDY ON THE SYNERGISTIC EXTRACTION OF URANYL NITRATE BY TRIBUTYL PHOSPHATE (TBP)-DIBUTYL BUTYL PHOSPHONATE (DBBP) MIXTURE

In this paper the synergistic extraction by a mixture of tributyl phosphate (TBP) and dibutyl butyl phosphonate (DBBP) for uranyl nitrate is studied. It has been found that maximum synergistic extraction effect occurs where the molar ratio of tributyl phosphate to dibutyl butyl phosphonate is five to one. The composition of the complex of synergistic extraction is UO2 (NO3)2·TBP·DBBP.The formation constant of the complex KTD=258±32. Mechanism of synergistic extraction and a possible structure of the complex is proposed.The effect of the total extractant concentration, concentration of nitric acid, temperature and concentration of sulphate on the distribution ratio of uranium is studied. The measured values of the distribution ratio of synergistic extraction agree quite well with the calculated values.