1,3-二(4-叔丁基苄氧基)杯[4]芳烃-(4-叔丁基)苯并冠-6对铯的萃取研究  

Solvent Extraction of Cs^(+)by Using 1,3-di(4-tert-butylbenzyloxy)-calix[4]arene-(4-tert-butyl)benzo-crown-6

作　　者：崔腾飞 徐臻 王浩龙 常青 唐超 靳强[1] 陈宗元[1] 杨素亮[2] 郭治军[1] CUI Tengfei;XU Zhen;WANG Haolong;CHANG Qing;TANG Chao;JIN Qiang;CHEN Zongyuan;YANG Suliang;GUO Zhijun(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China;Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]兰州大学核科学与技术学院,甘肃兰州730000 [2]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《原子能科学技术》2025年第2期292-300,共9页Atomic Energy Science and Technology

基　　金：甘肃省科技重大专项(21ZD8JA006)。

摘　　要：先进的后处理流程不仅要求回收乏燃料中全部的铀和钚,而且要求分离和回收关键裂变产物,如^(137)Cs和^(90)Sr。本工作合成并表征了1,3-二(4-叔丁基苄氧基)杯[4]芳烃-(4-叔丁基)苯并冠-6(L1)新配体;通过液-液萃取实验、负载有机相的质谱分析、UV光谱滴定实验、红外光谱分析等手段,研究了L1对Cs^(+)的萃取机理、萃取选择性和配位作用。结果表明,以正辛醇作为有机相稀释剂,L1对Cs^(+)的萃取在5 min内可达平衡,萃合物中L1与Cs^(+)的配位比为1∶1,25℃下萃取反应的表观平衡常数lg K_(ex)=3.31±0.07,萃取反应为放热反应,反应焓变为-54.0 kJ/mol。从模拟高放废液中萃取Cs^(+)的结果证实了L1对Cs^(+)有良好的选择性。此外,L1对Cs^(+)的萃取分配比和分离因子(SF_(Cs/M))均优于1,3-二(正辛氧基)杯[4]芳烃-冠-6(L2)的,表明L1有较好的应用前景。Advanced reprocessing processes require not only the recovery of all uranium and plutonium from the spent nuclear fuel,but also the separation and recovery of some key fission products,such as^(137)Cs and ^(90)Sr.“Fresh”spent nuclear fuel contains several Cs isotopes,such as^(133)Cs,^(134)Cs,^(135)Cs,^(136)Cs and^(137)Cs.^(134)Cs and^(136)Cs are mainly derived from neutron activation reactions,which are usually not the focus of attention because of their small amounts and short half-lives.^(133)Cs,^(135)Cs and^(137)Cs are mainly generated from fission reactions,and their cumulative fission yields are all around 6%.Among them,^(133)Cs is a stable nuclide,while^(135)Cs has an extremely long half-life(about 2.3 million years).On the other hand,^(137)Cs(t_(1/2)=30.2 a)is known mainly for its versatility.After the separation of Pu and U from the spent nuclear fuel with the plutonium uranium reduction extraction(Purex)process,radioactive Cs^(+)exists in the Purex raffinate with other fission products and minor actinides.1,3-alternate calix[4]arene-crown-6 ligands are among the best ligands regarding Cs^(+)separation from such kind of high-level liquid waste(HLLW).Many investigations were carried out to develop separation processes based on those ligands.In order to further improve ligand solubility in organic phase,reduce the loss of the organic phase,and avoid the occurrence of the third phase during the extraction process,many efforots have been made to tune the organic diluents and to modify of the molecular structures of the ligands.Since substituent groups on 1,3-alternate calix[4]arene-2,4-crown-6 have important effects on Cs^(+)extraction,it is possible to improve the extraction performance by using new substituents.In this study,a new ligand,i.e.,1,3-di(4-tert-butylbenzyloxy)calix[4]arene-(4-tert-butyl)benzo-crown-6(L1),was synthesized and characterized.The extraction mechanism,extraction selectivity and complexation of L1 to Cs^(+)were investigated by liquid-liquid extraction,MS analysis of the loading org

关 键 词：杯冠化合物 铯分离 高放废液 溶剂萃取 

分 类 号：TL283[核科学技术—核燃料循环与材料] O652.62[理学—分析化学]