Preparation of Non-Fluorine Glass Ceramics from Modified Molten Blast Furnace Slag

Non-fluorine glass ceramics were successfully prepared from modified molten blast furnace (BF) slag. Quartz sand and Al2O3 were added as modification material. Fe2O3, TiO2, and ZrO2 were added as nucleation agents. The thermal properties of the modified BF slag and the structure of glass ceramics were investigated by differential scanning calorimetry (DSC), scanning electron microscope (SEM) and X-ray diffraction analysis (XRD). The results indicated that the crystallization temperature (Tp) decreased with increasing BF slag, and the glass stability index ΔT initially decreased and then increased. As BF slag increased, the growth of akermanite in glass ceramics was enhanced, while the formation of diopside was not notably effected. The micro-hardness of glass ceramics reached 1082 Hv and the flexural strength was 70 MPa when the BF slag was 74 wt. %.