Glass-ceramic glazes have been prepared successfully via crystallization from blast-furnace slag (BFS), fly ash (FA) fluxed with potash feldspar and borax. The crystalline behavior of glass-ceramic glazes was investigated using differential thermal analysis and thermogravimetric analysis (DTA/TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results revealed that the major crystalline phases are anorthite (CaAl2Si2O8) and akermanite (Ca2MgSi2O7) and crystalline phases disperse well in glassy phases with a uniform size of 1 μm. Glass-ceramic glazes possess low density, low water absorption, perfect stain resistance, acid resistance and alkali resistance. The thermal expansion coefficient of glass-ceramic glazes is steady up to 800 oC with an average value of 7.2 × 10−6 /K. Final results suggest that BFS and FA have potential to be vitrified into economically and environmentally low-cost glass-ceramic glaze materials
Keywords: Blast-furnace slag (BFS), Fly ash (FA), Glass-ceramic glazes, Anorthite, Akermanite