亚临界水热法固化处理含碘敷银硅胶  

Treatment of silver-coated silica gel containing iodine waste by subcritical hydrothermal condition

作　　者：张玉钏 冯亚鑫 刘刈[1] 张赛 王志鹏 杨开迪 郭鹏 李宜宁 张生栋[1] 张振涛[1] ZHANG Yuchuan;FENG Yaxin;LIU Yi;ZHANG Sai;WANG Zhipeng;YANG Kaidi;GUO Peng;LI Yining;ZHANG Shengdong;ZHANG Zhentao(China Institute of Atomic Energy,Beijing 102413;University of South China,Hunan Hengyang 421001)

机构地区：[1]中国原子能科学研究院,北京102413 [2]南华大学,湖南衡阳421001

出　　处：《辐射防护》2024年第S01期90-96,共7页Radiation Protection

基　　金：国家自然科学基金项目“基于熔盐放射性废物构筑的固化体组成和物化性质研究”(U2267219)。

摘　　要：利用亚临界水热条件下产生的羟基自由基可以加速反应进程,以NaAlO2为原料处理自制的含碘敷银硅胶,加入质量分数5%的FD61玻璃粉作为添加剂形成了碘方钠石,对比了静态亚临界水热条件和动态亚临界水热条件下合成的碘方钠石固化体的物相、微观结构与形貌的差异。XRD结果表明动态亚临界水热条件下有利于形成碘方钠石;SEM-EDS结果表明,动态亚临界水热合成的碘方钠石形貌为规整的圆片状,粒径约为2μm,碘元素在固化体内分布均匀;TG-DSC结果表明动态亚临界合成固化体热稳定性较好,超过850℃以上会发生分解;XPS结果表明碘方钠石中碘元素是以I^(-)存在的。可为亚临界水热条件低温快速处理含碘敷银硅胶提供了一定的理论参考。This study utilizes the fact that hydroxyl radicals generated under subcritical hydrothermal conditions can accelerate the reaction process.The iodosodalite was formed by treating homemade iodine-containing silvercontaining silica gel with NaAlO2 as raw material and adding 5 wt.%FD61 glass powder as an additive.The differences under static subcritical hydrothermal conditions and dynamic subcritical hydrothermal conditions were compared in the physical phase,microstructure and morphology of the iodosilicate synthesized.The XRD results showed that the dynamic subcritical hydrothermal conditions were favourable for the formation of iodosodalite due to the full contact between the solid phase and the liquid phase by the constant stirring.The SEM-EDS results show that the iodosodalite synthesized under the dynamic subcritical hydrothermal perform a homogeneous morphology with regular round flakes and the particle size about 2μm.In the dynamic subcritical hydrothermal conditions,the iodine element is uniformly distributed in the solidification.The TG-DSC result shows that the synthesized solidified body has a good thermal stability,and can only decompose above 850℃.The XPS result shows that the elemental iodine in iodosodalite exists in the form of I^(-).The present work could provide some theoretical references for low-temperature and rapid treatment of iodine-containing silver-coated silica gel under subcritical hydrothermal conditions.

关 键 词：碘方钠石 亚临界水热法 含碘敷银硅胶 陶瓷固化 

分 类 号：TL941.11[核科学技术—辐射防护及环境保护]