摘要
为同时固化高放废物中的模拟放射性核素Sr、Ce和Sm,采用一步微波烧结工艺成功制备了Sr_(0.5)Zr_(2)(PO_(4))_(3)-(Ce,Sm)PO_(4)复相磷酸盐陶瓷固化体,采用XRD、Raman、SEM-EDS和密度表征研究了其物相组成、微观结构以及致密性,并利用PCT法评估了化学稳定性。结果表明:Sr_(0.5)Zr_(2)(PO_(4))_(3)相和(Ce,Sm)PO_(4)独居石相兼容性好,两相间不发生相互反应;所制备的复相陶瓷固化体晶粒尺寸小,相对密度高于96%,改变Sm/Ce比对固化体的微观结构和致密性无明显影响;PCT测试结果表明Sr、Ce和Sm的元素归一化元素浸出率都较低,与单相磷酸盐陶瓷固化体相比,复相磷酸盐陶瓷固化体具有较为优异的化学稳定性。
In order to simultaneously immobilize the simulated radionuclides Sr,Ce,and Sm in high-level radioactive wastes,Sr_(0.5)Zr_(2)(PO_(4))_(3)-(Ce,Sm)PO_(4) multiphase phosphate ceramic waste forms were successfully prepared in this paper by a one-step microwave sintering process.The phase composition,microstructures and density were investigated by XRD,Raman,SEM-EDS and densitometry,respectively.Meanwhile,the chemical stability was evaluated using the PCT method.The results show good compatibility between the Sr_(0.5)Zr_(2)(PO_(4))_(3) phase and the(Ce,Sm)PO_(4) monazite phase,with no mutual reactions occurring between the two phases.The prepared multiphase ceramic waste forms exhibit small grain size and a relative density exceeding 96%,with no significant impact on microstructure or density observed with changes in the Sm/Ce ratio.PCT test results show that the elemental normalized leaching rates of Sr,Ce and Sm are all lowlevel,demonstrating superior chemical stability compared to single-phase phosphate ceramic forms.
作者
刘缘
范林杰
刘昆奇
刘蝶
宋江
刘吉
王军霞
LIU Yuan;FAN Lin-jie;LIU Kun-qi;LIU Die;SONG Jiang;LIU Ji;Wang Jun-xia(School of Materials and Chemistry,Southwest University of Science and Technology,Mianyang 621010,China)
出处
《中国陶瓷》
CAS
CSCD
北大核心
2024年第6期13-21,共9页
China Ceramics
基金
国家自然科学基金面上项目(12275226)
国家大学生创新训练计划项目(202210619010)。
