RESEARCH Investigation of the usability of Sille stone as additive in floor tiles Çetin Öztürk 1 & Süleyman Akpınar 2 & Müge Tarhan 3 Received: 12 October 2020 /Revised: 30 December 2020 /Accepted: 8 January 2021 # Australian Ceramic Society 2021 Abstract Sille stone, a kind of silicate rock (SiO 2 > 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 mineral- ogical 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. Keywords Sille stone . Floor tile . Additive . Sintering . Characterization Introduction Floor tiles are usually manufactured from the ternary mixtures consist of clay, feldspar, and quartz raw materials [ 1] and generally possess a formulation containing ~50 wt% clay, 35 wt% feldspar, and 15 wt% quartz. Clay minerals serve to bind other raw ingre- dients, providing the plasticity required for body forming [ 2]. The low melting point feldspar minerals react with other components and lower the melt phase formation temperature of the system [ 3]. Thus, the produced melted phase penetrates the inside of the mi- crostructure lead to enhance densification [4]. Quartz is exceptionally stable at the firing stage and therefore prevents ex- cessive distortion and shrinkage [ 5]. The microstructures of ceram- ic tiles consist of crystalline phases such as anorthite, mullite, and quartz embedded in a glass matrix structure [ 6]. Ceramic tile production has been growing at least 300 mil- lion m 2 per year [7, 8]. This overgrowth in output causes to increase in the raw material demand, the worldwide consump- tion of which can be estimated at around 230 million tons per year [7]. For example, Turkey is one of the world’s leading ceramic tile manufacturers, and the consumed raw materials in production are estimated to be nearly more than 5 million tons [9]. The continuous increase in product quality in terms of technical performance and aesthetic appearance also increases the commercial success of ceramic tiles. This remarkable in- crease in product quality is due to the innovation process that has taken place in the last decade and is now widespread in every tile producing country. This innovation brought techno- logical revolutions such as fast-firing technology, which led to the disappearance of classical tile types and completely renewed the production cycle. As a result, the traditional ap- proach to the formulation and raw material selection of ceram- ic bodies has changed [7]. * Çetin Öztürk cozturk@konya.edu.tr 1 Department of Traditional Turkish Arts, Necmettin Erbakan University, Konya, Turkey 2 Department of Material Science and Engineering, Afyon Kocatepe University, Afyonkarahisar, Turkey 3 Faculty of Fine Arts, Department of Ceramic, Uşak University, Uşak, Turkey Journal of the Australian Ceramic Society https://doi.org/10.1007/s41779-021-00562-9