The use of perlite as flux in the production of porcelain stoneware tiles

Abstract

In this study, the effect of perlite from NW Turkey on the physical properties of ceramic tile bodies was investigated. The phases present in the raw materials were measured by X-ray diffraction while chemical analysis of the raw materials were determined by X-ray flouresence. Colour, water absorption and firing shrinkage of the raw materials were investigated. The data obtained from this study showed that the addition of NW Turkey perlites improved sintering behaviour of ceramic tile bodies, Therefore, alternative tile compositions were formulated using perlite as a substitute for common alkali bearing raw materials. The sintering behaviour of the standard bodies and that of the perlite containing bodies were characterized using a double-beam optical non-contact dilatometer. Moreover, the effect of perlite on firing shrinkage (%), water absorption (%), apparent porosity (%), apparent density (g/cm3), bending strength and colour values (L, a, b) were studied and resultant microstructures were characterized by X-ray diffraction (XRD) and scanning electron microscope studies (SEM). It was clearly observed that perlite improves sinterability of the tile bodies but increases the firing shrinkage due to the presence of water in its structure. The low thermal expansion values of the sintered bodies containing perlite makes it a visible raw material for porcelain stoneware tiles.