Drying and dehydrating of cement-bonded refractory castables are critical steps before industrial implementation. During the heat-up the steam transfer to the hot side can be interrupted due to the internal pressure build-up. As a result, the steam mass transport shifts towards the cold side because of the lower internal pressure on that side. Thus, the vapor pressure within the material increases even more, creating hydrothermal conditions and leading, in the worst case, to the feared spalling. These conditions in the material can be reproduced on a laboratory scale by using autoclave treatments.
The study, conducted at CAC, utilized two liquefiers and varied water content to achieve a deeper insight into the development of hydrate phases under hydrothermal conditions. It is expected that hydrothermal treatment at different temperature levels will induce varied crystal growth, thereby affecting pore size distribution within each material batch. The pore size distribution of the samples was determined using mercury intrusion porosimetry. This paper is part of a broader investigation, and its findings are correlated with additional research presented at the same conference, focusing on hydrate phase characterization through X-ray diffraction spectroscopy and Raman spectroscopy.