Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: Xue Shuyun x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

The extraction of uranium(VI) from sulfuric acid medium with tri-octylphosphine oxide (TOPO) in n-heptane was studied. Accompanied with the increase in the concentration of H2SO4, the distribution coefficient of uranium(VI) increased in the region of dilute sulfuric acid. When the concentration of H2SO4 surpassed 3.5 mol·dm−3, the distribution coefficient of uranium(VI) was at maximum. This result was due to the competition extraction between uranium(VI) and H2SO4. From the data, the composition of extracted species and the equilibrium constant of extraction reaction have been evaluated, which were (TOPOH)2UO2(SO4)2 (TOPO) and 107.6±0.15, respectively.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
Xue Shuyun
,
Yang Yonghui
,
Yang Yanzhao
,
Sun Sixiu
, and
Bao Borong

Abstract  

A study on solvent extraction of sulfuric acid by tri-octylphosphine oxide (TOPO) in n-heptane has been made. Extraction coefficients of H2SO4 as a function of H2SO4 concentration in aqueous phase, and extractant concentrations in organic phase have been studied. The composition of extracted species, equilibrium constants of extraction reaction have been evaluated. These results are important for interpreting extraction equilibrium data of uranium(VI) or other metal ions with TOPO in sulfuric acid media.

Restricted access

Abstract  

The synergistic extraction of uranium(VI) from sulfuric acid solution with primary amine N1923 and tri-octylphosphine oxide (TOPO) inn-heptane was studied. When the mole ratio of primary amine N1923 and TOPO is about 2∶1, the distribution coefficient will be the maximum. This result shows that primary amine N1923 and TOPO could exhibit the distinct synergistic effect for extraction of uranium(VI) from sulfuric acid solution. From the results of the extraction, it was suggested that the composition of synergistic extraction species is (RNH3)UO2(SO4)2·TOPO. The equilibrium constant (K 12) of synergistic extraction reaction has been evaluated, to be 1.07·109. In addition, the integration phenomenon of N1923 and TOPO have been discussed, the integration constant (K 3) is 1.60·102.

Restricted access

Abstract  

A study on extraction of uranium(VI) from sulfuric acid media by the primary amine N1923 in chloroform is described. Extraction coefficients of uranium(VI) as a function of aqueous H2SO4 concentration, extractant concentration and temperature have been studied. From the data, the compositions of extracted species, equilibrium constants and enthalpies of extraction reaction have been evaluated. A new extraction mechanism of amine has been suggested, that is the formation of reversed micelle as a result of the aggregation of ammonium salt in the organic phase of the extraction. This assumption may be used for interpreting extraction data satisfactorily, which can not be explained by the slope analysis method.

Restricted access