Crystallization behavior and properties of CaO-MgO-Al2O3-SiO2 glass-ceramics synthesized from granite wastes

Granite wastes were used as the raw materials for the preparation of CaO-MgO-Al2O3-SiO2 glass-ceramics. The waste loading was about 50.24-68.34 wt% in the batch depending on the chemical compositions of glasses. Effects of SiO2/(CaO + MgO) ratio on the crystallization behavior, microstructure and properties of glass-ceramics were investigated. The results showed that the crystallization activation energy Ec increased from 322.68 to 477.10 kJ/mol, and Avrami parameter n decreased from 3.78 to 2.89 as the SiO2/(CaO + MgO) ratio increase from 1.72 to 4.99, while, the crystallinity of diopside decreased gradually, and the main crystalline phase changed into armalcolite with SiO2/(CaO + MgO) ratio increase to 4.99. The increase in SiO2/(CaO + MgO) ratio lead to the decreasing in Vicker's hardness, bending strength and alkali resistance of the glass-ceramics, but improved the acid resistance.