Influence of calcite on the microstructure and sintering properties of the porcelain ceramic tiles at low temperature

Abstract

Porcelain ceramic tiles are low-temperature prepared by introducing multiple fluxes. The multiple flux compositions are potash feldspar-sodium feldspar-lithium porcelain stone-calcite four flux system. Effects of calcite contents on the microstructure, sintering and mechanical properties of the samples are studied in a fast firing process. The sintering behaviors of the samples are evaluated by linear shrinkage, water absorption and bulk density. The fired samples are characterized by X-ray diffraction, scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy and bending strength measurements. Well densification of the porcelain ceramic tiles is obtained at a low temperature 1130-1150°C. The sample prepared with 11% calcite exhibits higher shrinkage and bulk density, lower water absorption at a temperature of 1130°C. Higher bending strength at a composition containing at 11% calcite is due to appropriate densification and high anorthite, quartz and mullite crystallinity.