基于NTAamide(C8)萃取剂的酸性废液中锝分离工艺初步研究  

Preliminary study on the separation of Technetium from acidic wastewater using NTAamide(C8)extractant

作　　者：刘占元[1] 王均利 申震 罗方祥[1] 晏太红[1] 郑卫芳[1] 王辉[1] LIU Zhanyuan;WANG Junli;SHEN Zhen;LUO Fangxiang;YAN Taihong;ZHENG Weifang;WANG Hui(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：《核技术》2025年第2期100-106,共7页Nuclear Techniques

基　　金：国家国防科技工业局(No.BG20231200010,No.BG222512000203)资助。

摘　　要：在核燃料循环后段中,锝对高放废液的玻璃固化以及深地质处置有较大的影响,因此,有必要在乏燃料后处理过程中将锝提取出来,以减轻其不利影响。本文研究以NTAamide(C8)作为萃取剂从后处理硝酸介质中提取锝的优化工艺流程优化过程。基于NTAamide(C8)萃取锝、草酸洗涤杂质离子以及碳酸铵反萃锝的原理,设计了从后处理尾液中提取、纯化锝的工艺流程,并通过串级萃取工艺实验进行了初步验证。数据显示:草酸和硝酸浓度均为0.10 mol·L^(-1)时对各个杂质离子都有很好的洗涤效果,经8级萃取和8级洗涤,锝的萃取率为99.9%,而锶、铯、锆、钌的净化系数分别达到6.9×10^(3)、7.9×10^(4)、4.3×10^(2)、45,表明了该工艺在放射性废液中具有良好的锝分离与杂质离子净化性能。[Background]The presence of technetium in spent nuclear fuel reprocessing waste solution significantly increases the pressure of glass solidification and geological disposal of radioactive waste,and poses long-term potential radioactive hazards to the ecosystem.Therefore,it is necessary to separate and extract it in advance.[Purpose]This study aims to propose a process for the extraction and purification of technetium that can be well adapted to the plutonium uranium recovery by extraction(PUREX)process,providing support for engineering applications.[Methods]Based on the experimental data pertaining to the extraction and separation of technetium utilizing NTAamide(C8),a refined technetium separation process route containing technetium extraction and stripping with ammonium carbonate was meticulously designed whilst impurity ions were washed by oxalic acid mixed with nitric acid.Subsequently,validation of optimized process route was finalized through a series of cascade experiments with several stages'extraction and washing.[Results]Experimental results show that good washing effect on each impurity ion is achieved when the concentrations of oxalic acid and nitric acid are 0.10 mol·L^(-1).An exceptional technetium recovery rate of 99.9%is attained after 8-stage extraction and 8-stage washing process while the purification factors of strontium,cesium,zirconium,and ruthenium reach 6.9×103,7.9×10^(4),4.3×10^(2) and 45,separately.[Conclusion]This optimized process proposed in this study provides technical support for the separation and extraction of technetium in post-treatment plants.

关 键 词：锝 后处理 NTAamide(C8) 钚 

分 类 号：TL241.1[核科学技术—核燃料循环与材料]