SYNERGISTIC REGULARITY OF AB TYPE EXTRACTION MECHANISM OF U(Ⅵ) WITH BINARY SYSTEM HDBP+TBPO
YI Min; ZHANG Yanni; CHEN Dingfang; WANG Wenqing(Department of Technical Physics; Peking University)(Manuscript received 23 June; 1985; Revised manuscript 11 January; 1986)
Cite this article:
YI Min; ZHANG Yanni; CHEN Dingfang; WANG Wenqing(Department of Technical Physics; Peking University)(Manuscript received 23 June; 1985; Revised manuscript 11 January; 1986). SYNERGISTIC REGULARITY OF AB TYPE EXTRACTION MECHANISM OF U(Ⅵ) WITH BINARY SYSTEM HDBP+TBPO. Acta Metall Sin, 1987, 23(2): 230-233.
Abstract To resolve the obvious discrepancy between the results of HDBP+TBP and HDEHP+ TBP systems, the extractive process U(VI) from aqueous sulphate media by HDBP+TBPO dissolved in benzene has been studied. The difference between two mechanisms lies in the fact that whether the constituent of the synergic extracted complex is UO_2A_2(HA)_2TBPO or UO_2A_2(HA)TBPO. The composition of the complex was found to be UO_2A_2(HA)_2TBPO by means of slope method and equimolar series method. This is considered reasonable by predicating with cone packing model. Thermodynamic parameters for the formation of UO_2A_2(HA)_2TBPO at 298K were evaluated. The entropy change associated with the synergistic reaction (3) is 20J/mol·K, contributed by releasing a water molecule in TBPO reaction, which is in harmony with the data of TOPO system. From this result, it is possible to conclude that the synergism process is associated with adduct formation but no replacement of HA molecules.
