锕系元素分离研究:不对称双酰胺荚醚的萃取化学及应用  

Separation of Actinides:Extraction Chemistry and Application of Unsymmetric Diglycolamides

作　　者：刘耀阳 刘志斌 赵闯 周羽[1] 高杨[1] 何辉 Yaoyang Liu;Zhibin Liu;Chuang Zhao;Yu Zhou;Yang Gao;Hui He(College of Nuclear Science and Technology,Harbin Engineering University,Harbin 150001,China;China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]哈尔滨工程大学核科学与技术学院,哈尔滨150001 [2]中国原子能科学研究院,北京102413

出　　处：《化学进展》2020年第2期219-229,共11页Progress in Chemistry

基　　金：哈尔滨工程大学中央高校基本科研业务费(No.GK2150260176)资助。

摘　　要：PUREX乏燃料后处理流程排放出的高放废液,集中了乏燃料中95%以上的放射性,其中半衰期长、毒性大的次锕系核素是需要在地质处置库中将高放废液与生物圈隔离10万年以上的因素之一。为了更安全可靠地解决高放废液问题,国际上提出了“分离-嬗变”技术,即利用化学方法,将次锕系元素和长寿命裂变产物元素从高放废液中分离出来,根据分离出来元素的性质,对其加以利用或使其嬗变。分离-嬗变技术中的关键是对高放废液中不同类别元素的有效分离。双酰胺荚醚类萃取剂对高放废液中三价锕系、镧系元素展现出了优异的萃取性能,尤其是不对称双酰胺荚醚,在保持相应的对称性双酰胺荚醚良好的萃取性能的同时,在缓解或避免萃取过程中第三相形成方面也有较大优势。本文就不对称酰胺荚醚的历史沿革、合成方法、萃取性能、配位机理、流程工艺以及三相形成等几个方面进行了综述,就多种不对称双酰胺荚醚萃取剂对锕系、镧系及其他主要裂片元素的萃取分配比、分离系数、三相形成临界参数等进行了比较,对该类萃取剂后续的结构设计、配位机理研究及流程应用等方向提供了参考性建议。The high level liquid waste(HLLW)generated from PUREX reprocessing process contains more than 95%radioactivity of the spent fuel.Among HLLW,minor actinides with long half-life and high toxicity are one of the main factors that need to isolate HLLW from the biosphere for more than 100000 years in the deep geological repositories.In order to solve the problem of HLLW more safely and reliably,“separationtransmutation”technology has been put forward,that is,the minor actinides and long-lived fission product elements are separated from HLLW by chemical methods,and then the separated elements are utilized or transmuted according to their properties.The effective separation of different kinds of elements from HLLW is the key step in the separation-transmutation technology.The diglycolamide extractants exhibit excellent extractability towards trivalent actinides and lanthanides in HLLW.In particular,the unsymmetric diglycolamides have greater advantage than the corresponding symmetric diglycolamides in relieving or avoiding the formation of the third phase in the extraction process,and at the same time maintain the good extraction performances.In this paper,the development history,synthesis method,extraction performance,coordination mechanism,flow process,and the third phase formation of unsymmetric diglycolamides are reviewed.The extraction ratio,the separation factor and the critical parameters of the third phase formation of lanthanides,actinides and other major fission elements are compared.Some suggestions are provided for the structural design,coordination mechanism research and process application of the unsymmetric diglycolamides.

关 键 词：高放废液 锕系分离 萃取 不对称双酰胺荚醚 

分 类 号：O615.11[理学—无机化学] O658.2[理学—化学]