2,2′-((4-乙氧基-1,2-亚苯基)双(氧基))双(N,N-双(2-乙基己基)乙酰胺)对U(Ⅵ)、Pu(Ⅳ)的萃取行为研究  

Liquid-liquid Extraction of U(Ⅵ)and Pu(Ⅳ)with 2,2′-((4-Ethoxy-1,2-phenylene)bis(oxy))bis(N,N-bis(2-ethylhexyl)acetamide)

作　　者：丁琪秀 葛晓 朱浩玮 陈琦 吕洪彬[1] 郑卫芳[1] 晏太红[1] DING Qixiu;GE Xiao;ZHU Haowei;CHEN Qi;LYU Hongbin;ZHENG Weifang;YAN Taihong(Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《同位素》2022年第5期415-423,I0004,共10页Journal of Isotopes

摘　　要：为开发Pu(Ⅳ)的高选择性萃取剂,实现废液中微量钚的回收,以正十二烷作为稀释剂,研究2,2′-((4-乙氧基-1,2-亚苯基)双(氧基))双(N,N-双(2-乙基己基)乙酰胺)(4-EthoxyBenzoDODA)对U(Ⅵ)、Pu(Ⅳ)的萃取行为,以及两相混合振荡时间、水相硝酸浓度和有机相萃取剂浓度对U(Ⅵ)、Pu(Ⅳ)萃取分配比的影响。硝酸的萃取实验结果表明,4-EthoxyBenzoDODA(K_(H)=0.14)比BenzoDODA(K_(H)=0.44)碱性弱,更有利于选择萃取离子势较强的Pu(Ⅳ)。对U(Ⅵ)、Pu(Ⅳ)的萃取实验表明,Pu(Ⅳ)对U(Ⅵ)的分离因子最高可达6.9,Pu(Ⅳ)对Eu(Ⅲ)的分离因子最高可达223。采用斜率法分析了4.0 mol/L HNO_(3)浓度下U(Ⅵ)萃合物的组成,主要为UO_(2)(NO_(3))_(2)·L)、Pu(Ⅳ)(Pu(NO_(3))_(4)·L和Pu(NO_(3))_(4)·L_(2)共存。使用硝酸肼或者硝酸羟胺等还原反萃剂,可以将负载有机相中98%的Pu反萃至水相中。结果表明,4-EthoxyBenzoDODA对Pu(Ⅳ)具有一定的选择性。To develop a highly selective extractant for Pu(Ⅳ),2,2′-((4-ethoxy-1,2-phenylene)bis(oxy))bis(N,N-bis(2-ethylhexyl)acetamide),short for 4-EthoxyBenzoDODA,has been evaluated as a novel extractant in n-dodecane diluent for the extraction of U(Ⅵ)and Pu(Ⅳ).The effect of contact time of two phases,HNO_(3) concentration and extractant concentration on the distribution ratios of U(Ⅵ)and Pu(Ⅳ)was investigated.Acid uptake studies suggested that 4-EthoxyBenzoDODA(K_(H)=0.14)was less basic as compared to BenzoDODA(K_(H)=0.44),making it more conducive to selectively extract Pu(Ⅳ)with stronger ionic potential.Extraction experiments showed that the maximum of SF_(Pu/U),SF_(Pu/Eu) were 6.9,223 respectively.Slope analysis indicated extraction of 1∶1(ML)species with U(Ⅵ)and mixed 1∶1(ML)and 1∶2(ML_(2))species with Pu(Ⅳ)at 4.0 mol/L HNO_(3).98%of Pu in the loaded organic phase can be stripped to the aqueous phase using reductive stripping agent such as hydrazine nitrate and hydroxylamine nitrate.The results showed that the 4-EthoxyBenzoDODA exhibited good selectivity toward Pu.

关 键 词：铀 钚 选择性萃取剂 分离因子 

分 类 号：TL922[核科学技术—核燃料循环与材料] O65.11[理学—分析化学]