Abstract: Fly ash based refractory materials with varied alumina content (by controlling the raw materials with different ratios) at different sintering temperature were prepared using fly ash as the main raw material and coal gangue and industrial alumina as the auxiliary materials.The structural performance of the samples was tested;the microstructure was analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques.The results show that the compactness, mechanical properties, refractoriness as well as crystalline structure of the prepared refractory material are affected by both sintering temperature and alumina content.Desirable performance of bulk density 2.47 g/cm3, compressive strength 41 MPa, refractoriness 1450 ℃, and mullite and corundum as crystalline state are observed for the sample prepared at sintering temperature of 1350 ℃ and alumina content of 45%.The application of fly ash in refractory material preparation is meaningful in producing high-value added products with it.

Key words: fly ash;coal gangue;refractory material