氯化锂熔盐中八氧化三铀电解还原基础研究  

Electroreduction Fundamental Study of Solid U_3O_8 in Molten LiCl

作　　者：张宇[1] 袁中伟[2] 尹华意[3] 汤迪勇[3] 郑卫芳[2] 张生栋[2] 晏太红[2] 汪的华[3] 

机构地区：[1]国家国防科技工业局核技术支持中心,北京100080 [2]中国原子能科学研究院放射化学研究所,北京102413 [3]武汉大学资源环境学院,湖北武汉430072

出　　处：《原子能科学技术》2016年第4期591-596,共6页Atomic Energy Science and Technology

基　　金：863计划资助项目(2009AA050702)

摘　　要：将氧化物乏燃料直接电解还原为粗金属的过程是目前以电解还原-电解精炼为特征的主流干法后处理流程的重要步骤。二氧化铀(UO_2)是乏燃料的最主要成分,将致密的UO_2芯块转化为八氧化三铀(U_3O_8)粉末后,再进行电化学还原能有效提高还原速率。因此,以U_3O_8为研究对象,开展其在氯化锂(LiCl)熔盐中的电解还原机理研究,对后处理干法流程的开发具有重要的现实意义。本文在650℃的LiCl熔盐中,采用循环伏安法和恒电位电解法,研究U_3O_8的电解还原行为;对电解后的样品,运用XRD、SEM等手段分析其组成和形貌,并推测相应的还原机理。Direct reduction of spent oxide fuel to mix-metal is the key step of an important dry reprocessing process,which is feature with electroreduction-electrorefinning.UO2 is the main component in spent fuel.The transform of compact UO2 pellet to U3O8 powder could effectively improve the electroreduction rate.Therefore,taking U3O8 as research object,studying its electrochemical behaviors during the electroreduction process has certain practical significance for the development of this process.In this paper,the electroreduction behaviors of U3O8 in molten LiCl（650 ℃）were studied using cyclic voltammetry and constant potential electrolysis technology.The afterelectrolysis products were analyzed by XRD and SEM.Finally,a reduction mechanism was also proposed.

关 键 词：八氧化三铀 氯化锂 氧化锂 电解还原 

分 类 号：TL241.2[核科学技术—核燃料循环与材料]