摘要
介绍了Ｐ２０４－ＴＢＰ协萃体系用于乳状液膜法提取铀（Ⅵ）的研究。研究了在乳状液膜法中协萃载体ＴＢＰ的用量、乳状液膜制备条件、乳状液膜的膜相、膜内相和膜外相的组成对提取铀（Ⅵ）的影响。实验结果表明：（１）在硝酸铀酰体系中，膜相协萃载体ＴＢＰ占载体总量２０％—４０％时，铀（Ⅵ）的分配比是单一载体Ｐ２０４的３倍左右；在硫酸铀酰体系中，也有明显协同萃取效应。（２）当表面活性剂Ｓｐａｎ８０的体积分数为２％、膜内相Ｈ２ＳＯ４浓度为３—３．５ｍｏｌ／Ｌ时，可获得稳定的乳状液膜；膜外相ｐＨ控制在２左右，能获得满意的铀（Ⅵ）提取率；对铀（Ⅵ）含量较高的料液应该提高协萃载体浓度或适当增加乳状液与膜外相料液的体积比；料液中存在Ｆｅ３＋离子对液膜提取铀（Ⅵ）会产生不良影响，而ＳＯ２－４离子的影响并不明显。（３）Ｎａ２ＣＯ３溶液虽然也是铀（Ⅵ）的良好反萃剂，但它不能作乳状液膜法中提取铀（Ⅵ）的膜内相。膜内相的选择不仅考虑它是合适的常规反萃剂，而且要考虑膜内相与膜相的相容性。
The research on the UO 2+ 2 extraction behaviour in the P204 TBP synergistic extraction emulsion membrane system is introduced.The effects of synergist TBP on UO 2+ 2 extraction efficiency in the condition of P204 as carrier is studied.The preparation conditions of emulsion liquid membrane are selected.The effects of the composition of the emulsion liquid membrane including the internal phase,the external phase and membrane phase have been tested.The results show that (1)When the membrane phase synergist carrier TBP:20%—40% to the total amount of the carrier,the UO 2+ 2 distribution coefficient from UO 2(NO 3) 2 system is increased by about 3 times compared with single carrier P204 and similar effect is found for UO 2SO 4 system.(2)The stable emulsion liquid can be obtained by using 2% Span80 as the surfactant and 3%—3 5% H 2SO 4 solution as the internal phase.The efficiency of extraction for U(Ⅵ) is satisfied in condition of pH 2 in external phase. The more urany1 in external phase,the more synergist or the higher ratio of emulsion liquid to external phase solution should be used.The unexpected effect might occur when Fe 3+ exists in external phase solution,but the existence of SO 2- 4 has no obvious effect on the extraction of U(Ⅵ).(3)Though Na 2CO 3 solution is a good stripping agent for uranyl,but it can not be used as the internal phase for emulsion liquid membrane extraction of urany1.Therefore,the internal phase selection should take into account both the reagent′s stripping ability and the compatibility between the internal phase and the membrane phase.
出处
《核化学与放射化学》
CAS
CSCD
北大核心
1997年第1期11-17,共7页
Journal of Nuclear and Radiochemistry
关键词
乳状液膜
分离
铀
协同萃取
液膜法
Emulsion liquid membrane Uranyl Separation P204 TBP synergistic extraction system
