铯榴石玻璃陶瓷体的制备及固铯研究  

Study on the Preparation and Stability of Glass Ceramics for Curing Radioactive Cesium

作　　者：秦桂璐 张行泉 朱永昌 QIN Guilu;ZHANG Xingquan;ZHU Yongchang(Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory,Mianyang 621010,China;School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Analysis and Testing Center Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]核废物与环境安全国防重点学科实验室,绵阳621010 [2]西南科技大学材料科学与工程学院,绵阳621010 [3]西南科技大学分析测试中心,绵阳621010

出　　处：《玻璃》2021年第9期10-16,共7页Glass

基　　金：核废物与环境安全国防重点学科创新基地开放基金(17kfhk03)。

摘　　要：核能的安全利用是我国目前高度关注的重点,但核废料中含有的强放射性元素Cs及其同位素由于产率较高、半衰期较长且溶解性高而难以处理,如何对其进行安全处置亟待解决。铯榴石因其类似方沸石的结构而具有浸出率低、热稳定性好等优点,被认为是一种理想的固化放射性Cs的陶瓷材料。但是,传统的固相烧结工艺由于合成温度高而容易造成部分Cs的挥发造成二次污染,限制了铯榴石的应用。近年来,基于地聚物前驱体技术可以实现较低温度下铯榴石陶瓷的合成,但是所得陶瓷材料的力学性能及化学稳定性不佳。针对铯榴石在陶瓷制备中的问题,引入玻璃粉降低铯榴石陶瓷体的合成温度(<1000℃),同时实现对铯榴石中铯的二次保护。采用X射线衍射、拉曼光谱、扫描电子显微镜、硬度和密度测量以及电感耦合等离子体质谱等现代分析测试技术对系列样品的结构、微结构及化学稳定性进行了表征。结果表明:采用地聚物前驱体为原料,并加入适量的玻璃粉作为粘结剂,可以有效地降低铯榴石的合成温度,并改善微结构,增加致密度。经过浸出测试,玻璃粉的引入提高了铯榴石陶瓷的稳定性,实现了对铯榴石中铯的双重保护。The safe utilization of nuclear energy is the focus of our country’s attention at present. However, Cs and its isotopes, the main strong radioactive element of nuclear waste, are difficult to handle due to their high yield, long half-life and high solubility. How to safely dispose of them needs to be resolved urgently. Pollucite has the advantages of low leaching rate and good thermal stability due to its structure similar to analcime, and is considered to be an ideal ceramic material for curing radioactive Cs. But the traditional solid-phase sintering process is likely to cause secondary pollution due to the volatilization of part of the Cs from high synthesis temperature, which limits the application of pollucite. In recent years, the synthesis of pollucite ceramics at lower temperatures can be achieved based on geopolymer precursor technology, but the resulting ceramic materials have poor mechanical properties and chemical stability. Glass powder was introduced to reduce the synthesis temperature(< 1000℃) of pollucite and to realize the secondary protection of cesium in pollucite. Modern analytical testing techniques such as X-ray diffraction, Raman spectroscopy, scanning electron microscopy, hardness and density measurement, and inductively coupled plasma mass spectrometry were used to characterize the structure, microstructure and chemical stability of the series of samples. The results showed that using geopolymer precursors as raw materials and adding an appropriate amount of glass powder as a binder could effectively reduce the synthesis temperature of pollucite, improve the microstructure, and increase the density. After leaching test, the introduction of glass powder improved the stability of pollucite and realized the double protection of cesium in pollucite.

关 键 词：铯榴石 固相合成 地聚合物 稳定性 

分 类 号：O756[理学—晶体学]