Investigations of firing conditions in sanitaryware

In this thesis, the effect of composition on the firing conditions of sanitaryware is investigated in case overall flux mixture in the compositions is increased in the presence of alternative fluxes. For this reason, the quartz content of a conventional sanitaryware composition was partially replaced by sodium feldspar designated as experimental compositions. Spodumene, spodumene-dolomite and nepheline syanite were used as alternative fluxes and substituted for partially sodium feldspar. The phases present and their quantaties in the reference and experimental compositions were determined by Rietveld-X-ray diffraction (XRD) analyses. It was found that by increasing glassy phase content, firing temperature of sanitaryware could be decreased. On the other hand, the presence of spodumene and spodumene-dolomite slightly decreased the firing temperature when overall flux mixture in the compositions was increased. According to sintering kinetic studies, it was found that the glassy phase content was the effective parameter on the sintering speed of sanitaryware. According to scanning electron microscope studies (SEM), there was no noticable difference between reference and experimental compositions with respect to the distribution and shape of phases and pores that has been formed in the microstructure. Also, bending strength, firing shrinkage and pyroplastic deformation values of experimental compositions were similar to that of the reference composition. Moreover, the achievement of a lower thermal expansion coefficient value in the experimental compositions in comparison to the reference composition suggests that the residual quartz content is lower in the experimental compositions. Finally, the studies were conducted under industrial conditions. Also, it was observed that the experimantal compositions could be substituted for reference compositions. Moreover, % 20-30 energy costs of firing process related to firing temperature could be reduced.Key words: Sanitaryware, Alternative fluxes, Glassy phase content, Firing temperature