Preparation of CaO-SiO₂-Fe₂O₃-Al₂O₃ system glass-ceramics from red mud with high iron

Red mud-based glass-ceramics of CaO-SiO₂-FeO₃-Al₂O₃ system were prepared by melting-heat treatment from high-iron red mud with some SiO₂. The phase composition, morphology, crystallinity and bending strength of parent-glass and heat treated glass-ceramics were characterized. The crystallinity of each group of glass-ceramics was calculated by Rietveld full-spectrum fitting method. It is found that the crystallinity of glass-ceramics increases after heat treatment, and decreases with the addition of SiO₂. The flexural strength of glass-ceramics increases with the increase of SiO₂/red mud.