Effect of SiO2/Al2O3 ratio on sintering behavior, crystallization behavior and properties of diopside-anorthite glass-ceramics

Diopside-anorthite glass-ceramics were prepared by direct sintering with extracted titanium slag (ETS), coal fly ash (CFA) and quartz sand (SA), the effect of sintering temperature (1120-1180 degrees C) and the SiO2/Al2O3 ratio (1.85-2.63) on the phase transitions, physical characteristics and microstructure was examined by adding CFA (28.5-40%) and SA (0-12.5%) to ETS (60%). The results revealed that the sintering temperature and the ratio of SiO2/Al2O3 have a substantial impact on the sintering and processing properties of glass-ceramics. When the sintering temperature is lower than 1160 degrees C, the sample sintering is incomplete, and when the sintering temperature is higher than 1170 degrees C, the sample is prone to over-sintering and foaming. With the increase of SiO2/Al2O3 ratio, anorthite content increases, while diopside content decreases. When SiO2/Al2O3 ratio is 2.13, 1160 degrees C sintering 1 h, the better performance of diopside-anorthite-based glass-ceramics was prepared. The linear shrinkage, bulk density, water absorption and bending strength of the obtained glass-ceramics are 9.96%, 2.52 g/cm(3), 0.943%, and 96.1 MPa, respectively. The results show that the prepared glass-ceramics are industrially applicable.