Chinese Journal of Applied Chemistry ›› 2022, Vol. 39 ›› Issue (12): 1927-1936.DOI: 10.19894/j.issn.1000-0518.220198

• Full Papers • Previous Articles    

Extraction of Thorium(Ⅳ) Using Cextrant 230/Anionic Surfactant Sodium Bis(2-Ethylhexyl) Sulfosuccinate/n-Heptane Microemulsion

Yan-Ling LI1,2, Sheng-Ting KUANG1,3, Wu-Ping LIAO1,2,3()   

  1. 1.State Key Laboratory of Rare Earth Resource Utilization,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China
    2.School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026,China
    3.Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341000,China
  • Received:2022-06-02 Accepted:2022-08-29 Published:2022-12-01 Online:2022-12-13
  • Contact: Wu-Ping LIAO
  • About author:wpliao@ciac.ac.cn
  • Supported by:
    the National Key Research and Development Project of China(2019YFC0605003);the Strategic Priority Research Program of CAS(XDA02030100);Jiangxi “Double Thousand Plan”(jxsq.2020101005)

Abstract:

A stable microemulsion system is constructed by choosing α-aminophosphonate extractant Cextrant 230 and an anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as the cosurfactants. The effects of some factors such as pH and the concentration of Cextrant 230, AOT, NaOH and the sulfate in the aqueous solution on the maximum water ratio (x0) are studied. The process and effects of microemulsion formation are analyzed and the optimized conditions for the stable microemulsion are determined. The Cextrant 230-AOT-n-heptane microemulsion system is applied for the extraction of thorium. The effects of emulsion-to-water volume ratios, the concentrations of Cextrant 230, AOT and sulfate, temperature are studied. The extraction rate of thorium in the microemulsion system increases with the increase of the concentration of Cextrant 230 (or AOT), which is significantly higher than that of AOT-n-heptane microemulsion system. Cextrant 230 and AOT have a synergistic effect on the extraction of thorium. Temperature has little effect on extraction of thorium and the reaction is entropy-driven. Upon the comparison of the stripping of thorium by different inorganic acids, sulfuric acid is chosen as the stripping reagent. The loading capacity for ThO2 is about 1.43 g/L. This microemulsion system is applied to the separation of Th from the actual bastnaesite sulfate leach liquid after the cerium extraction and the thorium content can be reduced to less than 0.1 mg/L. The microemulsion system has both the advantages of thermodynamic stability and high efficiency.

Key words: α-Aminophosphonate, Reverse micelles, Extraction, Thorium

CLC Number: