For the production of ceramic wall tiles, effective sintering has become increasingly important in recent years to reduce firing times and/or peak firing temperatures and thus cope with high energy costs and environmental issues. This study was aimed to investigate the effects of alkaline-earth oxides on the fast-firing behaviour of wall tile bodies. To this end, several body formulations with different amounts of calcite and magnesite were prepared and fast fired under laboratory conditions. The sintering behaviour of the representative formulations was evaluated using a double-beam non-contact optical dilatometer (ODHT). Thermal properties were characterised by TG-DTA. Phase and microstructural analyses were performed by XRD and SEM, respectively. The results showed that an optimum combination of the aforementioned earth alkalines has a considerable influence on lowering the peak firing temperature, shortening the firing cycle and improving the glaze quality by lowering the decomposition temperature of carbonates in the formulations.

Keywords: Alkaline-earth oxides, Monoporosa Wall tile, Firing behaviour, Fast firing, Decomposition.