Thermo Physical and Mechanical Characterization of Lightweight Porous Ceramics Produced from Porcelain Polishing Residues

Traditional porcelain tile companies worldwide produce large amounts of residues during the polishing process. The recycling of these porcelain polishing residue becomes more critical. This study evaluates the incorporation of porcelain polishing residues as a raw material to produce lightweight porous ceramics as a new insulation material. Also, cellulose was used as the pore-making additive. The effect of sintering temperature and cellulose additive on the sintering behavior of porous ceramics, such as bulk density, linear shrinkage, water absorption were investigated. Flexural strength of the fired specimens was measured by three-point bending method. Thermal conductivities of the porous ceramics were predicted using laser flash method. Microstructural and phase observations were performed by scanning electron microscopy and X-ray diffractometry. Relatively low thermal conductivity of the samples sintered at 1100 degrees C was obtained at 0.097 W.m(-1).K-1 when 2.5 wt% cellulose additive was added, with low bulk density (<1 g.cm(-3)), water absorption (0.7%) and flexural strength (3.09 Mpa). These results indicate that the porcelain polishing residues could be used for lightweight porous ceramics production, thus giving rise to a new possibility for an environmental management of this abundant waste.