Analysis of tiles produced from a schist material and their ultraviolet, near-infrared, mid-infrared, longwave-infrared and far-infrared spectra

Abstract

Clays are used in the general production of earthen tiles. In this study, the production and characterization of earthen tiles from schist, a clayey rock formed by metamorphism of mudstone or shale, was investigated. The impact of tiles on atmospheric temperature through their absorption of the visible, near-infrared and far-infrared wavelength regions is evaluated. In particular, the absorption of ultraviolet and infrared radiation by the tiles was evaluated, as this could have beneficial applications for human health and the environment. UV-A radiation (320–400 nm) is not absorbed by the atmosphere, but schist materials absorb UV-A, which can contribute to melanoma formation (i.e. cancer). Field-emission scanning electron microscopy, X-ray fluorescence spectrometry and X-ray diffraction were used for the analysis of the schist materials. The tile-production stages of schist materials (drying, firing, water absorption rate, etc.) were tested at Hatipoglu Gunes Tile and Brick Industry, Inc. (Turkey). The tiles fired at 950°C and 1000°C comply with the industry standard compressive strength values for fired tiles (when converted to industry production conditions) and were 156.15 and 123.20 kg cm–2, respectively.

Muttalip green clay and its ultraviolet and infrared absorption and reflection

“…The converted flexural strength of the galette tiles obtained from the Muttalip green clay was greater than these values. Moreover, the flexural strength of the tiles prepared in this work was significantly greater than those obtained from schist materials (156.15 kg cm –2 ; Kuru Mutlu & Mutlu, 2022). Thus, the material alternatives available to the tile industry can be expanded by developing such clay mixtures, which will reduce the energy costs of industrial processes (Comin et al , 2021).…”

“…In this study, the drying and weight shrinkage values of the tiles were obtained and referred to collectively as the ‘drying shrinkage’. The tiles exhibited a drying shrinkage value that was only 0.45% greater than that of similar tile materials (Kuru Mutlu & Mutlu, 2022); this difference is not significant.…”

“…Cracks were observed on the surfaces of galette tiles obtained from Muttalip red clays (Kuru Mutlu, 2022), which exhibited a high SiO 2 content and were dried at 80°C. However, cracks were absent in galette tiles obtained from schist materials (Kuru Mutlu & Mutlu, 2022), which also exhibited a high SiO 2 content and were dried at 80°C. Thus, cracking is not related strongly to the SiO 2 content of the sample.…”