A new kind of diamide N,N,N’,N’-tetrahexylsuccinylamide（THSA） was synthesized, characterized and used for the extraction of HNO3, U（VI） and TI（IV） in a diluent composed of 0.5 volume fraction 1,2,4-trimethy be...A new kind of diamide N,N,N’,N’-tetrahexylsuccinylamide（THSA） was synthesized, characterized and used for the extraction of HNO3, U（VI） and TI（IV） in a diluent composed of 0.5 volume fraction 1,2,4-trimethy benzene（TMB） and 0.5 volume fraction kerosene（OK）. Extraction distribution coefficients of U（VI） and TI（IV） as functions of aque- ous nitric acid concentration, extractant concentration, temperature and salting-out agent （LiNO3 ） have been studied, and it is found that THSA as an extractant is superior to TBP for extraction of U（VI） and TI（IV）. Back extraction was also studied. At low acidity, the main adduct of THSA and HNO3 is HNO3.THSA. THSA.（HNO3）2 and THSA.（HNO3）3 are also found at high acidity. The compositions of extracted species, apparent equilibrium constants and enthalpies of extraction reactions have also been calculated.展开更多
Separation of Th4+ and RE3+ was investigated by hollow fiber membrane extraction with N1923 in countercurrent recirculating operation. The effect of H+ concentration in aqueous phase and flow rates of aqueous and orga...Separation of Th4+ and RE3+ was investigated by hollow fiber membrane extraction with N1923 in countercurrent recirculating operation. The effect of H+ concentration in aqueous phase and flow rates of aqueous and organic phases on mass transfer coefficient was tested. Then the extraction of Th4+ from RE sulfate obtained from Baotou ore was carried out. The results obtained show that the mass transfer coefficient of Th4+ changes with the flow rate of aqueous phase, but does not change with the flow rate of organic phase and H+ concentration in aqueous phase, which suggests that the mass transfer rate of Th4+ is controlled by that in the water critical layer. The mass transfer rate of RE3+ does not change with the flow rate of water phase, changes a little with the flow rate of organic phase, and changes with H+ concentration, which suggests that the mass transfer rate is controlled by their reaction rate with N1923. Th4+ could be extracted completely in 8 h from RE sulfate solution of Baotou ore withrelatively less extraction of RE3+. So the separation of radioactive element under the sealed condition could be done.展开更多
The dependence of THMA extraction behaviour for U(VI) alld Th(IV) on nitric acid concentration, THMA concentration and molecular structure of extracted complex has been studied. For nitric acid solutions of 3.0mol/L a...The dependence of THMA extraction behaviour for U(VI) alld Th(IV) on nitric acid concentration, THMA concentration and molecular structure of extracted complex has been studied. For nitric acid solutions of 3.0mol/L a coordinative mechanism may possibly dominate in the extraction of metal cations. The complex composition of UO2(NO3)2(THMA)2,Th(NO3)4 (THMA)2 and Th(NO3)4 (THMA)3 are proved.展开更多
The extraction behavior of N, N, N’, N’-tetraisobutul-3 -oxy-dioctlylglutaramide to Uranium (VI) and Thorium (IV ) fromnitric acid solution was studied by using n-octnol and kerosene as diluent . This extractant can...The extraction behavior of N, N, N’, N’-tetraisobutul-3 -oxy-dioctlylglutaramide to Uranium (VI) and Thorium (IV ) fromnitric acid solution was studied by using n-octnol and kerosene as diluent . This extractant can not only effectively extract threevalence lanthanide and actinide, but also extract four-and six-valence actinide such as Uranium(VI) and Thorium (IV). Theresults show that the distributions of U (VI) and Th (IV) increase with the concentrations of nitric acid, Th Du . Theextraction mechanism of U(VI) and TI0V)can be inferred to be the neutral compex extraction, the structural formulas of theextractives are UO2(NO3)2. L and Th(NO3)4. L, lgKexU(VI)=(VI).455±0.09, IgK’exTh(IV)=1.66±0.04 respectively. Thisextractant can be easily synthesized and is insoluble in water, stable toward radiation nontoxic. The extracted U (VI) and Th (IV)can be effectively stripped. It can be completely decomposed without any renmants. This is good for disposal of radioactivewaste.展开更多
The extraction behavior of N,N-diethyl-N,N-dibenzenyl-urea（DEDBU）and N,N-dimethyl-N,N-dibenzenyl-urea（DMDBU）to uranium（VI）and thorium（IV）from nitric acid solution was studied by using xylene or chloroform as d...The extraction behavior of N,N-diethyl-N,N-dibenzenyl-urea（DEDBU）and N,N-dimethyl-N,N-dibenzenyl-urea（DMDBU）to uranium（VI）and thorium（IV）from nitric acid solution was studied by using xylene or chloroform as diluent.The effect of aqueous HNO3 concentration,extractant concentration,salting-out agent concentration and aqueous UO2+2/Th4+concentration on extraction distribution ratio of U（VI）and Th（IV）was determined.The results show that the extraction behavior of the extractants DEDBU and DMDBU to U（VI）is similar to that of TBP,the solvation numbers both are two.Under the experimental condition,the extractants DEDBU and DMDBU do not show the extraction behatvior to Th（IV）.This means that the estractants may have potential application to separate U（VI）and Th（IV）.展开更多
文摘A new kind of diamide N,N,N’,N’-tetrahexylsuccinylamide（THSA） was synthesized, characterized and used for the extraction of HNO3, U（VI） and TI（IV） in a diluent composed of 0.5 volume fraction 1,2,4-trimethy benzene（TMB） and 0.5 volume fraction kerosene（OK）. Extraction distribution coefficients of U（VI） and TI（IV） as functions of aque- ous nitric acid concentration, extractant concentration, temperature and salting-out agent （LiNO3 ） have been studied, and it is found that THSA as an extractant is superior to TBP for extraction of U（VI） and TI（IV）. Back extraction was also studied. At low acidity, the main adduct of THSA and HNO3 is HNO3.THSA. THSA.（HNO3）2 and THSA.（HNO3）3 are also found at high acidity. The compositions of extracted species, apparent equilibrium constants and enthalpies of extraction reactions have also been calculated.
文摘Separation of Th4+ and RE3+ was investigated by hollow fiber membrane extraction with N1923 in countercurrent recirculating operation. The effect of H+ concentration in aqueous phase and flow rates of aqueous and organic phases on mass transfer coefficient was tested. Then the extraction of Th4+ from RE sulfate obtained from Baotou ore was carried out. The results obtained show that the mass transfer coefficient of Th4+ changes with the flow rate of aqueous phase, but does not change with the flow rate of organic phase and H+ concentration in aqueous phase, which suggests that the mass transfer rate of Th4+ is controlled by that in the water critical layer. The mass transfer rate of RE3+ does not change with the flow rate of water phase, changes a little with the flow rate of organic phase, and changes with H+ concentration, which suggests that the mass transfer rate is controlled by their reaction rate with N1923. Th4+ could be extracted completely in 8 h from RE sulfate solution of Baotou ore withrelatively less extraction of RE3+. So the separation of radioactive element under the sealed condition could be done.
文摘The dependence of THMA extraction behaviour for U(VI) alld Th(IV) on nitric acid concentration, THMA concentration and molecular structure of extracted complex has been studied. For nitric acid solutions of 3.0mol/L a coordinative mechanism may possibly dominate in the extraction of metal cations. The complex composition of UO2(NO3)2(THMA)2,Th(NO3)4 (THMA)2 and Th(NO3)4 (THMA)3 are proved.
文摘The extraction behavior of N, N, N’, N’-tetraisobutul-3 -oxy-dioctlylglutaramide to Uranium (VI) and Thorium (IV ) fromnitric acid solution was studied by using n-octnol and kerosene as diluent . This extractant can not only effectively extract threevalence lanthanide and actinide, but also extract four-and six-valence actinide such as Uranium(VI) and Thorium (IV). Theresults show that the distributions of U (VI) and Th (IV) increase with the concentrations of nitric acid, Th Du . Theextraction mechanism of U(VI) and TI0V)can be inferred to be the neutral compex extraction, the structural formulas of theextractives are UO2(NO3)2. L and Th(NO3)4. L, lgKexU(VI)=(VI).455±0.09, IgK’exTh(IV)=1.66±0.04 respectively. Thisextractant can be easily synthesized and is insoluble in water, stable toward radiation nontoxic. The extracted U (VI) and Th (IV)can be effectively stripped. It can be completely decomposed without any renmants. This is good for disposal of radioactivewaste.
文摘The extraction behavior of N,N-diethyl-N,N-dibenzenyl-urea（DEDBU）and N,N-dimethyl-N,N-dibenzenyl-urea（DMDBU）to uranium（VI）and thorium（IV）from nitric acid solution was studied by using xylene or chloroform as diluent.The effect of aqueous HNO3 concentration,extractant concentration,salting-out agent concentration and aqueous UO2+2/Th4+concentration on extraction distribution ratio of U（VI）and Th（IV）was determined.The results show that the extraction behavior of the extractants DEDBU and DMDBU to U（VI）is similar to that of TBP,the solvation numbers both are two.Under the experimental condition,the extractants DEDBU and DMDBU do not show the extraction behatvior to Th（IV）.This means that the estractants may have potential application to separate U（VI）and Th（IV）.
