High-strength tile production from yellow clay with high silicon dioxide content and its reflection in ultraviolet and visible regions

Presently, there is an increasing global demand for high-quality raw materials in tile production owing to rapid urbanization. In addition, the issues of insufficient reserves and low-quality clays are resolved by exploring the potential of environmentally friendly Bilecik yellow clay with high SiO2 content. In this study, the feasibility of producing high-strength earthen tiles from yellow clay, which has a higher SiO2 content than that of commercially used clays, is investigated. X-ray diffraction, field-emission scanning electron microscopy, and X-ray fluorescence spectroscopy are employed to analyze yellow clay. The tiles are produced in the Hatipoglu Günes Tile and Brick Industry Inc. factories. Galette tiles are obtained using a vacuum press device. Then, the galette tiles are fired at temperatures of 900, 950, and 1000 °C in an electric and Hoffman furnace. The tile fired at 1000 °C exhibits the highest transformed flexural strength (305.371 kg/cm2), which is 2.55 times higher than that specified in the TS EN 1304:2016 standard (Turkish standard-European norm). In addition, reflectance measurements are performed in ultraviolet and visible regions through UV–VIS and Fourier-transform infrared spectroscopy; the results confirmed that the galette tiles are reflected in the UV-C region. Therefore, it can be concluded that galette tiles exhibit sterilization and disinfectant effects under appropriate conditions. The usability of yellow clay with high SiO2 content in industry, the availability of high-strength products, and its production stages will create an important database for literature.