在HCl介质中DCH(二环己基)系列的五种冠醚对U(Ⅵ)的萃取

EXTRACTION OF URANIUM(VI) WITH A SERIES OF FIVE DCH(DICYCLOHEXYL) CROWN ETHERS IN HCI MEDIUM

  • 摘要: 本工作主要研究了26种不同结构的冠醚对UO_2Cl_2的萃取,重点研究了DCH-18-C-6,DCH-21-C-7,DCH-24-C-8,DCH-27-C-9及DCH-30-C-10的二氯乙烷溶液在HCl体系中萃取UO_2Cl_2的条件。实验结果表明,几种DCH系列冠醚萃取U(VI)的D(分配比)均随着HCl浓度的增加而增加,当 HCl浓度为 7.0 N时,呈现最大值。再继续增加时又显著下降。该体系中U(VI)与五种冠醚的络合物组成均为1:2。在其它条件相同时,萃取U(VI)用HCl体系比用HNO_3体系的D大约大二个数量级。用稀酸或水反萃一次即完全。

     

    Abstract: This paper reports the extraction of UO_2Cl_2 by 26 crown ethers of differentstructure from HCl solution, with the emphasis on the following five crown ethers:DCH--28--C--6, DCH--21--C--7, DCH--24--C--8, DCH--27--C--9 and DCH--30--C--10 in the1,2--dichloroethane solution. Experimental results show that distribution coefficients(D) of U (VI) increase with the increase of HCl concentration, approach amaximum in 7 N HCl, and then sharply decrease. The stoichiometric ratio of U(VI)to crown ethers in the complexes is 1:2. When other conditions are the same, thedistribution coefficients in HCl medium are two orders of magnitude higher thanthose in HNO_3 medium. Extracted U (VI) can be completely stripped from theorganic phase by a single bed--extraction process with dilute acids or water.

     

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