Structural characterization of glass–ceramics made from fly ash containing SiO2–Al2O3–Fe2O3–CaO and analysis by FT-IR–XRD–SEM methods

Abstract

The glass–ceramics has been proposed as a useful recycling fly ash from thermal power plants. In this study, C type fly ash containing SiO2–Al2O3–Fe2O3–CaO has been sintered to form glass–ceramic materials at different temperatures between 850°C and 1050°C after using powder processing based on milling and powder compaction without inorganic additives. The effect of firing temperatures between 850°C and 1050°C on mineralogy and microstructure of sintered samples is reported. The Fourier Transform Infrared Spectra (FT-IR), Differential Thermal Analysis (DTA), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques were applied on the sintered powder form. From the XRD results, the amount of quartz decreases on sintering, when the sintering temperature increases. On the basis of SEM observations, new crystallites structure developed in the microstructures of the C type of fly ash samples and the glassy region decreased at the crystallization temperature.