Abstract: In order to achieve high-value utilization of kaolinite type coal gangue in North China, the circular economy of mining area is developed. This paper reported anorthite glass-ceramics was successfully prepared using the kaolinite type coal gangue from Xiegou colliery of Shanxi Province by the sintering process. The effect of different TiO₂ content on the crystallization behavior and the performance of the final prepared glass-ceramics was studied by the methods of X-ray photoelectron spectroscopy, X-ray diffraction, differential scanning calorimetry, physical properties test, etc. The results show that the crystallization temperature of anorthite glass-ceramics decreases from 979.3 ℃ to 915.8 ℃ with the mass fraction TiO₂ increase from 1.09% to 7.09%, and the main crystalline phase can always keep with anorthite, suggesting the TiO₂ content increase reduces the crystallization temperature without change the main crystalline phase. The appropriate addition of TiO₂ can promote the generation of crystal nuclei and increase the number of grains significantly, and the single crystal particles become fine, thus increasing the compactness of glass-ceramics and improving its physical and chemical properties. The glass-ceramics obtained after nucleation at 800 ℃ for 2 h and crystallization at 1 025 ℃ for 2 h with TiO₂ content of 5.09% have excellent physical and chemical properties, with bulk density of 2.88 g·cm^-3, acid resistance of 97.93%, alkali resistance of 99.98%, and flexural strength of 124.5 MPa. The prepared glass-ceramics have excellent performance and good application prospect.

Key words: anorthite glass-ceramics, coal gangue, kaolinite, titanium dioxide, crystallization behavior