Glass-Ceramics Produced by Vitrification of Coal Fly Ash

Glass-ceramics based on CAS (CaO-Al2O3-SiO2) system was produced by controlled crystallization of vitrified fly ash. Fly ash was pre-treated by magnetic separation and nonmagnetic part of fly ash (NFA) was used. Maximal crystallization of parent glass occurs in the temperature region from 900 oC to 1160 oC. Glass-ceramics was produced by consolidation of parent glass i.e. pressing (45 MPa) and sintering at 950, 1000, 1050 and 1100 oC, and isothermal time at the final temperature of 30, 60, 120 minutes. The dominant crystalline phase was calcium aluminum silicate (anorthite). The obtained glass-ceramics could be potentially used in construction applications.