Preparation of ceramic wall tiling derived from blast furnace slag

Blast furnace slag, the by-product of Turkish iron and steel production, has gradually been added to ceramic wall tile compositions. The effects of blast furnace slag have been studied by measuring the linear shrinkage, water absorption, dried strength, fired strength, thermal expansion coefficient and color value of tiles. A basic mixture, suitable for producing ceramic wall tiles with raw materials provided from the Yurtbay Ceramic Company (Eskişehir/Turkey), with the same composition as used in industry, was prepared. Compositions were prepared with blast furnace slag (BFS) waste replacing limestone and kaolin in the basic mixture, either partially or totally. The microstructures of sintered tiles and phase compositions were studied using a scanning electron microscope (SEM) and X-ray diffraction (XRD). The SEM result shows that anorthite containing a glassy phase has a higher amount of CaO content with an increase of blast furnace slag. The mechanical properties were measured according to ISO-EN 10545-4. When the observed samples are compared with a standard, the samples with waste show high strength due to the amount of crystalline phases and a low thermal expansion value. The experiment reveals that the addition of 33% BFS in ceramic wall tiles results in about a 25% increase in strength. The results also indicate that blast furnace slag is a potential secondary raw material for the production of wall tiles.