Valorization of aluminium slags to produce sustainable ceramic wall tiles

Abstract

The aim of this study is to recycle aluminum slag as a raw material for ceramic tile production. The non-metallic part of the slags, which are multi-component systems consisting of metal and non-metallic parts, was dissolved in water by washing. After three washes, the slag was calcined at 1200 degrees C for 4 h, and each stage of the slag was examined by X-ray analysis (XRD), scanning electron microscopy (SEM) to confirm the removal of harmful materials, and elemental analysis by energy-dispersive X-ray spectroscopy (EDX) has been made. The slag was added to the wall tiles at a ratio of 1, 3, 5, 7, 10, and 15 wt.%. While the green strength value of the standard wall tile was 1.20 N/mm(2), this value increased to 3.06 N/mm(2) with 10 wt.% slags. Also, the fired strength value increased from 10.66 to 27 N/ mm(2) with the addition of 10 wt.%. Since slags in wall tiles cause a twofold increase in raw strength and fired strength values, aluminum slag can be easily used instead of strength-increasing mixtures in thin wall tiles. The sample strength increase is also supported by the porosity ratios calculated using SEM images. By using slags, a 30 degrees C reduction in sintering temperatures will also contribute to the reduction in CO2 emissions. After slags, the mechanical values provided standard wall tile values, and some lightening was observed in the tile colors.