Investigation of factors affecting the rheology of ceramic slurry and optimization of physicomechanical properties of industrial ceramic tiles based on sintering temperature and time using response surface methodology

The thesis study consists of four work packages. The overall aim of work package one is to investigate the effect of plasticizers with different chemical structures on slurry rheology. In this context, organic and inorganic deflocculants were added to the floor tile recipe at different rates in the range of 0.1-1% and their fluidizing effects on slurry rheology were measured instead of sodium silicate plasticizer. At the same time, deflocculant samples together with silicate were added to the recipe in a maximum ratio of 1% in total, and it was determined whether their interactions were synergistic, additive, and antagonistic effects on the slurry rheology. The molecular structures and determination of intramolecular bonds of each deflocculant samples were compared using IR-spectroscopy. Expansion behavior with optical dilatometer, surface characteristics and elemental analysis with SEM-EDX for microstructure analysis, phase analysis with XRD analysis, characteristic temperature points with heat microscope were determined of the ceramic bodies obtained with different types of deflocculants. Even if commercial deflocculants have synergistic and additive effect on slurry, unit cost values is very high than sodium silicate. At the work package two, it was thought that the rheological properties could also be improved with the raw materials in the recipe compared to the different commercial deflocculants. In this context, the recipes have been developed with different raw materials at different rates in order to improve the rheological values. It was detected that the recipe from these trials with the lowest thixotropic slurry property was the "SPK53" sample with a density of 1758 kg/m3. Since the firing conditions of the developed "SPK53" coded recipe were aimed to be in optimum conditions, statistical models were designed for the sintering temperature and time. Models were designed and verified with the selected dependent variable (flexural strength, water absorption, and firing shrinkage) and independent variables (sintering temperature and sintering time). Thanks to the models, it has been seen that it is possible to obtain ceramic tile with the desired with physical properties. Thus, thanks to the developed models, it is not only aimed to save natural gas during the spray drying process, but also to reduce water consumption and to minimize all energy costs by bringing the sintering regime to optimum conditions.