Study the Effect of Substitution of Zirconium Silicate in the Ceramic Glaze by Aluminum Silicate, MgO, CaO and Al2O3 on the Optical Properties

To make a white surface of ceramic glazes, zirconium silicate (zircon) particles are dispersed in the glaze body. Due to the high difference between the refractive index of zircon particles and that of the glazed body, the surface of the glaze scatters and reflects most of the light. Since zircon is expensive, some research has been done to find a cost-effective alternative for it. In this paper zircon was substituted by CaO, MgO, Al2O3 and also aluminum silicate as frit in the ceramic glaze and the effects on the physical properties of the surface were studied. Some samples with these materials were prepared and the reflectance spectra, whiteness index and the color parameters in CIEL*a*b* color space were studied. To study the composition and microstructure of the samples SEM and XRD experiments were performed. The results shown the sample which some part of zircon in the opacifier layer (engobe) was substituted by new compounds, had almost the same properties as full zircon sample.