Thermal conductivity of red clays as a function of temperature: A novel approach for elimination of systematic measurement uncertainties.

The global production of fired ceramic bricks represents a large environmental burden in form of energy consumption and greenhouse gasses emission. The production process has therefore become an object of interests of several studies aiming at its optimization to reduce the negative environmental impacts. Within these optimizations, the precise knowledge of thermal properties of clays undergoing the firing process is one of the key information that conditions the successful solution of the problem. This paper therefore aims at determination of temperature-dependent thermal conductivity of clays. Using a set of thermocouples, the temperature distribution in the sample is monitored, being exposed to one-sided heating. The temperature field deformation due to presence of metal wires is then overcame using computational modelling that is able to distinguish the particular contributions of clay/thermocouples to the ongoing heat transfer. Based on this assumption, such a thermal conductivity of clay is then sought, that provides the same temperature distribution as the experiment. The thermal conductivity values of clays were found to range between 0.58 W·m−1·K−1 and 1.97 W·m−1·K−1, depending on the temperature. [ABSTRACT FROM AUTHOR]