Measurement of apparent sintering activation energy for densification of clays

Abstract Clays are raw materials with properties that are necessary for the manufacture of ceramic tiles. The characteristics of clay ceramic raw materials may vary within the same mineral deposit. Clay blending promotes better use of clay reserves, thereby increasing the applicability and life cycle of raw materials. Therefore, it is important to understand the mechanisms controlling the firing of ceramic tiles. In this study, three different clays from a clay deposit were assessed and ten formulations were prepared using the mixture design method. The formulations were analysed using differential thermal and thermogravimetric analyses and dilatometric analysis. Subsequently, the most refractory and fluxing formulations were subjected to thermal tests under various heating rates, similar to the process used for the calculation of apparent sintering activation energy for the densification of clays and for pyroplasticity tests. It is suggested that a mineral deposit can be assessed based on activation energy and thermal kinetics, expanding the alternatives available to the miner through the planning of mixtures with various clays and thus reducing the energy costs of the industrial process.