热处理制度对温石棉尾矿微晶玻璃析晶行为的影响

Effects of Heat Treatment on Crystallization Behaviors of Glass-Ceramics from Chrysotile Asbestos Tailing

基于热处理制度对微晶玻璃析晶行为的重要影响,研究了核化温度和晶化温度对CaO-MgO-SiO2系温石棉尾矿微晶玻璃析晶行为的影响。通过DTA分析初步确定基础玻璃成核和晶化温度范围;采用X射线衍射和扫描电镜分析微晶玻璃的物相组成和显微形貌。结果表明:随着核化和晶化温度的升高,微晶玻璃样品主晶相由铁橄榄石转变为黄长石,且样品的析晶能力逐渐增强;次晶相镁橄榄石和透辉石逐渐消失。且通过热处理过程使石棉纤维相变为对环境无害的硅酸盐矿物。

Based on the significant effects of heat treatment on crystallization behaviors of glass-ceramics,influences of nucleation temperature and crystallization temperature on crystallization behavior of CaO-MgO-SiO2 glass-ceramics were studied.Heating temperatures for nucleation and crystallization were both determined by using DTA curve of the parent glass.Crystalline phase and microstructure of the glass-ceramics were investigated by means of X-ray diffraction（XRD） and scanning electron microscope（SEM）.The results indicate that the main crystalline akermanite of the glass-ceramics converted into melilitite and the crystallization ability was improved with increasing nucleation and crystallization temperature,meanwhile,the minor crystalline phase diopside and forsterite were disappeared gradually.The toxic asbestos fibers converted into silicate materials and became harmless for environment after the heat treatment process.