Synthesis and properties of building glass-ceramics from thermal power station fly ash

The aim of the present work is to investigate the possibility of using coal fly ash (a waste product from the Sliven thermal power station in Bulgaria) in the production of glass and glass-ceramic materials. The chemical composition of the waste was determined by X-ray fluorescence analysis. The waste product mainly contained SiO2, Al2O3, CaO, and Fe2O3. Differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and infrared spectroscopy (IRS) were used for the analysis of the glass-ceramics. Serial techniques were used to determine properties such as micro-hardness, density, thermal expansion coefficient, and chemical resistance of the glass samples and glass-ceramic samples. The sintered glass-ceramic materials were characterized by an appearance similar to that of natural stones. The sintered glass-ceramic materials could be used for cladding materials for walls, floors, and roofs.