甲醛肟在Purex流程铀钚分离中的应用  

Application of Formoxmine in Separation of Pu From U in Purex Process

作　　者：肖松涛[1] 叶国安[1] 罗方祥[1] 刘协春[1] 杨贺[1] 兰天[1] 孟照凯[1] 

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：《核化学与放射化学》2013年第2期73-79,共7页Journal of Nuclear and Radiochemistry

摘　　要：为了进一步优化Purex流程,研究了甲醛肟(FO)的硝酸水溶液对30%TBP/煤油中Pu(Ⅳ)的还原反萃取行为,考察了FO浓度、两相接触时间、两相相比、反萃液硝酸浓度、NO3-浓度、有机相U浓度和温度对Pu(Ⅳ)的还原反萃的影响。结果表明:延长两相接触时间能显著提高Pu(Ⅳ)的反萃率,增加甲醛肟的浓度、降低反萃液酸度、降低NO3-浓度、增加有机相U浓度和升高温度也对Pu(Ⅳ)的反萃率有一定的提高。采用16级逆流反萃取实验(还原反萃段12级,补充萃取段4级),模拟Purex流程1B槽U/Pu分离工艺,在相比(1BF∶1BX∶1BS)为4∶1∶1的条件下,U和Pu的回收率均大于99.99%;铀中去钚的分离因子SF(Pu/U)=1.0×104;钚中去铀的分离因子SF(U/Pu)=8.3×104。FO作为新型络合-还原反萃取剂,可有效实现铀钚分离。In order to optimize the Purex process, the reduction stripping behavior of Pu（Ⅵ） from 30% TBP/OK with formoxmine （FO） was investigated. The effect of temperature, FO concentration, HNO3 concentration, NO;- concentration, U concentration in organic phase, contacting-time and phase ratio was studied, respectively. The results show that the stripping percentage of Pu（Ⅵ） increases.with the phase contacting-time, FO concentration, U concentration in organic phase and the temperature, and decreases with HNO3 concentra- tion, NO3 concentration. The separation of Pu from U by FO in 1B contactor was carried out using 16-stage counter current extraction （in which 4 stages for supplemental extraction, 12 stages for stripping）. At phase ratio （1BF： 1BX ：1BS） =4 ：1：1, the recovery percent- ages of both U and Pu are more than 99.99%. The separation factor of Pu over U is 1.0×10^4, and the separation factor of U over Pu is 8.3 ×10^4. The present work indicates that FO as a new organic reducing and complexing agent can effectively achieve the separation of Pu from U.

关 键 词：Pu(Ⅳ) 甲醛肟 还原反萃 铀钚分离 

分 类 号：TL241[核科学技术—核燃料循环与材料]