Influence of Kaolin on the Sintering of Glass Powder to Glass-Ceramics

Glass powder derived from a waste water flocculate was used to prepare sintered glass-ceramics. Different amounts of kaolin as a binder were mixed with the glass powder to form green bodies. The influence of the kaolin on the sintering, crystallization of the glass powder and on the microstructure of the obtained glass-ceramics has been investigated. DTA analysis suggests that the kaolin increases the crystallization temperature of the glass-kaolin mixtures. The results also show that the kaolin benefits reducing the sintering shrinkage of the green bodies. The kaolin does not lead to the change of crystalline phases in the sintered glass-ceramics. Instead, with an appropriate addition, the kaolin can provide reactive Al2O3 and SiO2 sources due to its decomposition favoring the crystal growth and improving the mechanical property of the sintered product.