Effects of CaO/SiO2 ratio and CaCl2 content on the densification, microstructure, and properties of sintered CaO–MgO–Al2O3–SiO2–CaCl2 glass-ceramic.

The effects of CaO/SiO 2 ratio (basicity) and CaCl 2 addition amount on the properties of CaO–MgO–Al 2 O 3 –SiO 2 –CaCl 2 glass-ceramics (GC) were investigated. When sintered at 825 °C, the increase in basicity from 0.35 to 0.75 reduced the porosity of GCs from 1.1 to 0.8 vol%, but the increase of CaCl 2 addition amount from 5 to 10 wt% increased the porosity from 0.8 to 7.0 vol%. The main crystalline phase of GC changed from augite (Ca(Mg 0 · 7 Al 0.3) (Si 1 · 7 Al 0.3)O 6) to Ca 10 Al 12 Cl 2 Si 5 O 37 by increasing the CaCl 2 addition amount to 7.5 wt%. The increase in CaCl 2 addition had adverse effects on the bending strength and Vickers hardness, while the rise in basicity deteriorated the bending strength but had little impact on the Vickers hardness. This study may have a guiding significance for preparing slag-based GCs and treating CaCl 2 -containing wastes. [ABSTRACT FROM AUTHOR]