Abstract: The silicate-calcium slag generated in process of extracting alumina from high-alumina fly ash was used as the main raw material to prepared wollastonite glass-ceramics by sintering method .The effect of amount of silicate-calcium slag additions and heat treatment conditions on crystallization process , microstructures and properties of the prepared glass-ceramics were studied by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods.The results indicate that prolong nucleation time and crystallization time could help to wollastonite crystal orientation grown up and closely arranged , and have a significant influence on mechanical properties of glass-ceramics, while the crystallization temperature and nucleation temperature have relatively small influence .With the amount of silicate-calcium slag increasing , wollastonite precipitation from matrix glass is enhancing and signal crystal phase of wollastonite glass-ceramics were prepared under the conditions of add 70 .98%silicate-calcium slag in raw material on the conditions of heat treating at 800 ℃for 90 min followed by crystallization at 920 ℃for 90 min.

Key words: silicate-calcium slag;wollastonite;glass-ceramics;fly ash