CaO-Al2O3-SiO2系粉煤灰微晶玻璃的析晶动力学及电子探针分析

利用烧结法制备了CaO-Al2O3-SiO2系粉煤灰微晶玻璃。采用差热分析方法确定了析晶峰温度Tp,研究了其晶析动力学,并利用JMA方程获得的析晶动力学参数k（Tp）制备玻璃热稳定性。采用X射线衍射、电子探针-能谱分析方法研究了微晶玻璃中玻璃基体、晶相的组成。研究结果表明：析晶活化能Ea为591.5kJ/mol,指前因子A为1.87×1013min-1,k（Tp）判据表明玻璃的稳定性随升温速率的增加而降低;升温速率对主晶相的种类没有影响,即均为单一的β-硅灰石,其尺寸大小约为2～20μm;基体玻璃中原子种类十分复杂,既有网络形成体,又有网络修饰体和网络中间体,其性质与Na2O SiO2玻璃相近。

Crystallization Kinetics and Electron Probe Microanalysis of CaO-Al_2O_3-SiO_2 Glass-Ceramics from Coal Fly-Ash

A glass-ceramic of CaO-Al2O3-SiO2 was prepared from coal fly-ash by a sintering method.The crystallization peak tem-perature Tp was calculated by differential thermal analysis,the crystallization kinetic was investigated,and the thermal stability of glass was estimated by the crystallization kinetic.The crystalline phase and matrix of the glass-ceramic were characterized by X-ray diffraction and electron probe microanalysis-energy spectrum analysis,respectively.The results show that the activation energy Ea is 591.5 kJ/mol,and the index A is 1.87 × 1013 min-1.According to the k(Tp),the stability of the glass decreased with increasing the heat-ing rate,and the heating rate had little effect on the major crystalline phases.The β-wollastonite was the single crystalline phase with the grain sizes of 2-20 μm.The atoms in the glass matrix,which involved the network former,the modified cation and the intermedi-ate former as well,were rather complicated.The property of the matrix was similar to that of the glass of Na2O?SiO2.