Investigation of the usability of Sille stone as additive in floor tiles

Sille stone, a kind of silicate rock (SiO2 > 65%), which is an example of the natural building blocks that have been widely used throughout history, is an andesitic type volcanic rock belonging to the Sille region of Konya province (Turkey). Sille stones, which are building materials used extensively for floor pavement and wall covering in both indoor and outdoor applications, have many artefacts from the Seljuk and Ottoman times until today. In this study, Sille stone powders were used to partially substitute the traditional raw materials to formulate floor tiles based on industrial manufacturing. Sille stone powders to the floor tile composition up to 20 wt% were incorporated to examine their potential effects on the finished product. The additive-induced changes in the structural and technical properties of floor tile samples were characterised in detail using chemical and mineralogical analysis (X-ray diffraction and fluorescence spectrophotometry) and thermal analysis (DTA, TG, and dilatometry test) as well as physical and mechanical tests. According to the results, the usage of Sille stone powders in floor tile compositions decreased the water absorption of the bodies and increased firing shrinkage. The mechanical strength of the bodies improved with the use of Sille stone powders. As a result, the recycling of the Sille stone powders wastes is a promising approach to manufacture traditional ceramic tiles, and their utilization in floor tile compositions could be possible by adjusting the body composition and/or industrial conditions.