水合磷酸盐沉淀富集模拟锕系核素Ce的研究  

Investigation of the Actinide Enrichment by Rhabdophane Precipitation Using Cerium as a Surrogate

作　　者：罗添 赵骁锋 滕元成[1] 刘航 LUO Tian;ZHAO Xiaofeng;TENG Yuancheng;Liu Hang(School of Materials and Chemistry,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;The Key Laboratory of Advanced Materials(MOE),School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]西南科技大学材料与化学学院,四川绵阳621010 [2]清华大学材料科学与工程学院先进材料重点实验室,北京100084

出　　处：《西南科技大学学报》2024年第4期65-72,99,共9页Journal of Southwest University of Science and Technology

基　　金：国家自然科学基金(12105236);四川省科技计划资助(2023NSFSC1313);西南科技大学博士基金(21zx7104)。

摘　　要：针对放射性废液中锕系核素的富集分离问题,以Ce模拟锕系核素,采用化学沉淀法制备水磷铈石(CePO_(4)·nH_(2)O),研究了温度、pH值等对Ce^(3+)去除、沉淀物相组成、微观结构和脱水热行为的影响。结果表明:沉淀产物水磷铈石的化学式为CePO_(4)·0.667H_(2)O,其沉淀过程可分为均质快速成核阶段(小于2 h)和受离子沉积影响的晶粒生长阶段;相较于晶粒生长阶段,成核过程更易受pH值影响,提高pH值有助于Ce^(3+)的快速去除;在温度90℃,pH值为3.0~5.0溶液中反应2 h后Ce^(3+)的沉淀率均大于99%,分离出的CePO_(4)·0.667H_(2)O在775℃下转变为独居石(锕系核素理想的宿主相)。水合磷酸盐是一种极具应用前景的锕系核素分离-固化材料。In response to the enrichment and separation of actinide nuclides in radioactive waste liquid,Ce was used to simulate actinide nuclides,and CePO_(4)·n H_(2)O was prepared by chemical precipitation method.The effects of temperature,pH value on Ce^(3+)removal,precipitate phase composition,microstructure,and dehydration heat behavior were studied.The results show that the chemical formula of the precipitation product rhabdophane is CePO_(4)·0.667H_(2)O.The precipitation process of CePO_(4)·0.667H_(2)O can be divided into the homogeneous rapid nucleation stage(less than 2 hours)and the grain growth stage influenced by ion deposition.Compared with the grain growth stage,the nucleation stage is more susceptible to the influence of pH value,and increasing pH value is conducive to the rapid removal of Ce^(3+).In a solution with a temperature of 90℃and a pH of 3.0-5.0,the removal rate of Ce^(3+)is over 99%after a 2 hour precipitation reaction.The separated CePO_(4)·0.667H_(2)O transforms into the monazite phase,which is an ideal host for incorporating actinides.Hydrated rhabdophane is a highly promising material for separating and solidifying actinide nuclides.

关 键 词：水磷铈石 锕系核素 沉淀法 富集分离 固化 

分 类 号：TQ133.3[化学工程—无机化工] X591[环境科学与工程—环境工程]