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  • Author or Editor: Bao Bo-Rong x
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Abstract  

It was found that N,N,N,N-tetrabutylsuccinylamide (TBSA) in a diluent composed of 50% 1,2,3-trimethylbenzene (TMB) and 50% kerosene (OK) can extract thorium(IV) ion from a nitric acid solution. The results of the extraction study suggested the formation of a 141 thorium(IV) ion, nitrate ion and N,N,N,N-tetrabutylsuccinylamide complex as extracted species. The related thermodynamic functions were also calculated.

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Abstract  

N,N,N′,N′-tetrahexylsuccinylamide (THSA) was used for the extraction of U(VI) and Th(IV) ions from nitric acid media into n-dodecane. Extraction distribution ratios of U(VI) and Th(IV) as a function of nitric acid concentration, extractant concentration and temperature have been studied. It was found that THSA as a new extractant is superior in some aspects to TBP for extraction of U(VI) and Th(IV). The extraction of nitric acid was also investigated. At low acidity, the main adduct of THSA and HNO3 is THSA·HNO3. THSA·(HNO3)2 and THSA·(HNO3)3 also formed at high acidity. The composition of the species, equilibrium constants and enthalpies of the extraction reactions have also been calculated. The suggested formation of the 1:2:1 ratio of uranyl(VI) ion and the 1:4:2 ratio of thorium(IV) ion, nitrate ion and THSA as the extracted species was further confirmed by the IR spectra of U(VI) and Th(IV) extracts.

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Abstract  

A new bifunctional extractant named phenyl-N,N-dibutylcarbamoylmethyl sulfoxide (PCMSO) is synthesized and characterized in order to investigate its selectivity and capability in the extraction from acidic nitrate media in nuclear reprocessing. The extraction of uranium (VI) with PCMSO in toluene has been studied at various concentrations of nitric acid, extractant and salting-out agent (LiNO3). The mechanism of extraction is discussed in the light of the results obtained. The extracted species has also been investigated using FT-IR spectrometry. The related thermodynamic functions were calculated. The IR spectral study was also made of the extracted species.

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Abstract  

The influence of the concentration of nitric, hydrochloric and phosphoric acids, petroleum sulfoxides (PSO), salting-out agent, kind of diluent and temperature on the distribution ratio of U(VI) and Th(IV) has been systematically studied. It is found that the extraction regularity of PSO is similar to that of TBP. The distribution ratio in phosphoric acid is lower, but it increases with the increase of hydrochloric acid concentration and reaches a high value. The U(VI) exhibits the maximum distribution ratio at 3–4 mol/l HNO3. The distribution ratio of U(VI) and Th(IV) increases rapidly in the presence of a salting out agent. The extracted compounds are determined to be UO2(NO3)22PSO and Th(NO3)42PSO. The extraction enthalpies of U(VI) and Th(IV) with PSO were also calculated.

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Abstract  

The partition of uranium(VI) between nitric acid and N,N-dibutyldecanamide (DBDEA) in kerosene has been investigated at various concentrations of nitric acid, extractant and salting-out agent LiNO3. The mechanism of extraction is discussed in the light of the results obtained. The effect of TBP on the extraction of uranium(VI) with DBDEA has also been considered. There is an apparent synergistic effect with these two extractants at low concentration of TBP, however, one sees a decrease in extraction distribution at higher concentration. IR spectra show that there is no apparent interaction between the two kinds of extractants. The stoichiometry of the synergistic extracted species has been determined.

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Abstract  

N,N,N′,N′-tetrabutylmalonamide (TBMA) was used for extraction of uranyl(II) ion from nitric acid media into n-dodecane. The effects of nitric acid concentration, extractant concentration, temperature and back extraction on distribution coefficients of uranyl(II) ion have been studied. The extraction of nitric acid is also studied. The main adduct of TBMA and HNO3 is (TBMA)2·HNO3 in 1.0 mol/l nitric acid solution. The 1:2:2 complex of uranyl(II) ion, nitrate ion and TBMA as extracted species is further confirmed by IR spectra of the extraction of uranyl(II) ion with TBMA. The values of thermodynamic parameters have also been calculated.

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Abstract  

The extraction of U(VI) from nitric acid solutions with di-(1-methylheptyl) phosphoric acid has been investigated. The dependence on nitric acid concentration, DMHPA concentration and temperature has been considered and the infra-red spectra of extracted species and extractant were recorded. The mechanism of extraction is discussed in the light of the results obtained.

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Abstract  

The extraction of uranium(VI) from nitric acid by N-octanoylpiperidine (OPPD) in toluene has been investigated at varying concentrations of nitric acid, extractant, salting-out agent LiNO3 and at different temperatures. The mechanism of extraction is discussed in the light of the results obtained. The extracted species have also been investigated using FT-IR spectrometry. The related thermodynamic functions were calculated.

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Abstract  

A new extractant, N-octanoyl-2-methylpiperidine (OMPPD) has been synthesized. The extraction of U(VI) with N-octanoyl-2-methylpiperidine (OMPPD) in nitric acid has been studied. The dependence of the partition reaction of U(VI) on the concentrations of nitric acid, extractant, salting-out agent LiNO3, and temperature has been studied. In the light of the results, the extraction mechanism is discussed. The synergistic extracted complexes may be presented as UO2(NO3)2(OMPPD)2 . The related thermodynamic functions were calculated.

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Abstract  

N,N'-Dioctanoylpiperazine (DOPEZ), a novel extractant for U(VI) in carbon tetrachloride has been studied. The principal factors affecting the U(VI) distribution ratio, i.e., the concentration of aqueous nitric acid, extractant, salting-out agent and temperature, were investigated.

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