硝酸肼还原反萃取分离镎/钚的研究  

Separation Np from Pu based on reduction-stripping by using hydrazine nitrate as reductant

作　　者：杨贺[1] 张虎[1] 李丽[1] 黄小红[1] 王日腾[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：《核技术》2016年第9期33-40,共8页Nuclear Techniques

基　　金：国家自然科学基金(No.91326111)资助~~

摘　　要：镎的提取和分离是国际后处理领域重点关注的研究课题之一。在Purex流程中,硝酸肼常被用来作为亚硝酸的清扫剂,此外,由于硝酸肼对Np(VI)和Pu(IV)的氧化还原反应具有选择性,理论上可以利用其反应速率上的差异来实现镎与铀钚的分离。为探索硝酸肼分离镎/钚工艺提供可行性,本文采用单级萃取设备研究了硝酸肼还原反萃Np和Pu的过程。通过研究硝酸浓度、硝酸肼浓度和反应温度对还原反萃过程的影响,确定了Np(VI)和Pu(IV)反萃动力学方程和表现活化能。进一步通过动力学方程得出硝酸肼还原反萃Np(VI)和Pu(IV)的半反应时间,并对Np(VI)/Pu(IV)分离过程的工艺进行了初步探索。Background： Extraction and separation of neptunium is one of the topics focused in reprocessing. Hydrazine nitrate is often used as a cleaning agent for nitrous acid in the Purex process. In addition, due to the selectivity of hydrazine nitrate for the redox reactions of Np（VI） and Pu（IV）, theoretically the difference of the reaction rate can be used to separate the neptunium from uranium and plutonium. Purpose： In order to explore the feasibility of separation for neptunium and plutonium with hydrazine nitrate, this paper adopts the single stage extraction experiments to research the process of reductive stripping of neptunium and plutonium. Methods： By investigating the effects of the concentration on nitric acid and hydrazine nitrate, as well as reaction temperature on the reductive stripping process, the Np（VI） and Pu（IV） stripping kinetics equation and apparent activation energy were determined. Further, the half reaction time of reductive stripping Np（VI） and Pu（IV） with hydrazine nitrate can be obtained by means of kinetics equation, and a preliminary exploration for Np（VI）/Pu（IV） separation was carried out. Results and Conclusion： The rate equations of the reaction Np（VI） with hydrazine and Pu（IV） with hydrazine were respectively obtained. Further, the half reaction time of reductive stripping Np（VI） and Pu（IV） with hydrazine nitrate can be obtained by means of kinetics equation, and a preliminary exploration for Np（VI）/Pu（IV） separation was carried out.

关 键 词：硝酸肼 还原反萃 分离镎钚 

分 类 号：TL241.1[核科学技术—核燃料循环与材料]