A preparation and performance study of glass-ceramic glazes derived from blast furnace slag and fly ash

Autores: Lu, HX|He, M|Liu, YY|Guo, JF|Zhang, LW|Chen, DL|Wang, HL|Xu, HL| Zhang, R
Fuente: J. ceram. process. res.
12(5), 588-591
2011

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 (CaAl(2)Si(2)O(8)) and akermanite (Ca(2)MgSi(2)O(7)) and crystalline phases disperse well in glassy phases with a uniform size of 1 mu m. 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 degrees C with an average value of 7.2 x 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.