高熵烧绿石(La_(1/6)Pr_(1/6)Nd_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))_(2)Zr_(2)O_(7)固化锕系核素的结构和化学稳定性研究  

Structure and Chemical Durability of Actinide Nuclides Solidified by High-Entropy Pyrochlore (La_(1/6)Pr_(1/6)Nd_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))_2Zr_2O_7

作　　者：杜瞻远 朱永昌 崔竹 焦云杰 董炫疆 王东宇 杨德博 王华 DU Zhanyuan;ZHU Yongchang;CUI Zhu;JIAO Yunjie;DONG Xuanjiang;WANG Dongyu;YANG Debo;WANG Hua(China Building Materials Academy Co.,Ltd.,Beijing 100024,China)

机构地区：[1]中国建筑材料科学研究总院有限公司,北京100024

出　　处：《硅酸盐通报》2024年第9期3399-3406,共8页Bulletin of the Chinese Ceramic Society

摘　　要：高熵陶瓷(HECs)具有优异的相稳定性和化学稳定性,是一种潜在的高放废物固化基材。本文设计了一种高熵稀土锆酸盐烧绿石固化基材(La_(1/6)Pr_(1/6)Nd_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))_(2)Zr_(2)O_(7),用镧系元素铈(Ce)模拟放射性的锕系核素,采用高温固相法成功制备了一系列固化Ce^(4+)的(La_(1/6)Pr_(1/6)Nd_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))2(Zr_(1-X)Ce_(X))_(2)O_(7)(0≤X≤0.5)陶瓷固化体,并对固化体的物相组成、微观结构、微观形貌、抗浸出性能进行了测试。结果表明:所有模拟核素皆均匀地固溶进晶体结构中;随着CeO_(2)含量增加,晶体结构由有序烧绿石结构转变为缺陷萤石结构;Ce元素归一化浸出率处于10^(-7)~10^(-6) g·m^(-2)·d^(-1),表现出优异的化学稳定性。High-entropy ceramics(HECs) are a potential target for high-level waste curing due to their excellent phase and chemical stability.In this work,a high-entropy rare-earth zirconate pyrochlore(La_(1/6)Pr_(1/6)Nd_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))_(2)Zr_2O_(7) was designed.And the lanthanide element Ce was used as simulated radioactive actinide nuclides.A series of ceramic solidifications(La_(1/6)Pr_(1/6)Nd_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))_2(Zr_(1-X)Ce_X)_(2)O_(7)(0≤X≤0.5) were prepared using a high temperature solid phase method to solidify Ce.The solidifying performances were evaluated by analyzing the physical phase composition,microstructure,microscopic morphology,and anti-leaching.The results show that all the nuclides are uniformly solidly dissolved into crystal structure.As the CeO_(2) content increases,the crystal structure changes from an ordered pyrochlore phase to a defective fluorite phase.The normalized leaching rates of Ce range from 10^(-7) g·m^(-2)·d^(-1) to 10^(-6) g·m^(-2)·d^(-1),showing excellent chemical stability.

关 键 词：高熵陶瓷 高熵烧绿石 高放废物 陶瓷固化 化学稳定性 

分 类 号：TQ174.75[化学工程—陶瓷工业]