二(2-乙基己基)磷酸大块液膜中传输四价铈的研究

二(2-乙基己基)磷酸(DEHPA)一直成功的作为一种含有氯仿膜的大块液膜载体有效的传输Ce~(4+)。文章采用有氯仿膜的大块液膜方法进行Ce~(4+)的传输研究,结果表明:pH为2左右的料液中含有纯净的Ce~(4+)或者Ce~(4+)与一些阳离子二者的混合物,这些阳离子包括Ca~(2+),Mg~(2+),Na~+,K~+,Pb~(2+),Fe~(3+),Cu~(2+),以及UO~(2+)等,而0.1mol/L的盐酸为传输池中分散相的反萃取剂。大于99%的Ce~(4+)会在2h以内有选择的渗入液膜以内,而在相同时间内其他阳离子的传输量将少于3%。料液相中存在的Fe~(3+)和UO~(2+)的存在对铈离子的传输有极大的影响。Fe~(3+)可以有效地利用加入到料液中的硫氰化钾或柠檬酸加以掩蔽,但是UO~(2+)的共传输却只能利用加入到料液相中的碳酸盐或硫氰酸盐来加以减少。

Transport of Tetravalence Cerium through Bulk Liquid Membrane by Di(2-ethylhexyl)Phosphoric Acid

Di(2-ethylhexyl)phosphoric acid(DEHPA)was used as a carrier for the selective successfully and efficient Ce4+transport across a bulk liquid membrane of chloroform. In this paper,the bulk liquid film with chloroform film is used to carry out the transmission of Ce4+. The results show that:the feed comprised of a phase of pure Ce4+or a binary mixture of Ce4+and cat-ions,such as Ca2+,Mg2+,Na+,Pb2+,Fe3+,K+,Cu2+,and UO2+,in water maintained at pH 2, while 0.1 mol/L hydro-chloric acid served as a stripping agent in the receiving compartment of the permeation cell. Greater than 99% of Ce4+selectively permeated across the membrane in less than 2h,while the transport of other cations present along with thorium was less than 3% during the same time selectivity of the transport of thorium was greatly affected by the presence of Fe3+and UO2+in the feed phase. Fe3+could be effectively masked by the addition of SCN-or citric acid to the feed phase but the cotransport of UO2+could only be partially reduced by the addition of carbonate or thiocyanate to the feed phase.