This UNITECR 2022 paper is an open access article under the terms of the Creative Commons Attribution License, CC-BY 4.0, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited. DRYING OF REFRACTORY CASTABLES – HOW COMPLEX THE MODELLING NEEDS TO BE? A NUMERICAL AND EXPERIMENTAL STUDY M. H. Moreira(1)*, S. Dal Pont(2), R. F. Ausas(3), T. M. Cunha(1), A. P. Luz*, (1) , V. C. Pandolfelli(1) (1) Federal University of Sao Carlos, Graduate Program in Materials Science and Engineering, Sao Carlos, SP, Brazil (2) CNRS, Grenoble INP, 3SR, Université Grenoble Alpes, 38000 Grenoble, France (3) Institute of Mathematical and Computer Sciences, University of São Paulo, 13566-590, São Carlos, SP, Brazil ABSTRACT Calcium aluminate cement (CAC)- bonded castables have numerous benefits when compared to monolithic refractories. Their main drawback is their long initial heating, when the physical and chemically-bonded water are released. If the mass flux of water to the ambient is lower than the vapor generation, the gas pressure can increase well above the material’s strength resulting in cracks and spalling of the ceramic lining. In order to avoid this, optimized heat up curves are needed, and one promising methodology by using numerical models. Most of these calculations are based on tools used for simulating Portland cement concrete structures on fire and they vary both in complexity and their basic assumptions. Thus, the main question that remains is how complex such models need to be in order to capture the fundamental aspects of this phenomenon. The present work aimed to solve this issue by implementing multiple numerical tools reported in the literature with distinct complexity levels and fundamental assumptions and by also conducting neutron tomography tests on a CAC-bonded castable. It was possible to see that the pressure values predicted by such methodologies are equivalent and the water content predicted is qualitatively similar within the models and with the experimental values, indicating that the simplest approach might be used for predicting the castables’ drying. INTRODUCTION Refractory monolithics were developed as an option to shaped products, as they offer several distinct features such as a greater degree of freedom to adjust and install the composition and, as a consequence, a more detailed control over the properties of the final product. These characteristics lead to several benefits and, finally, over time it has been one of the most used classes of refractories1. Aiming to increase the service time and performance of these linings, the design of monolithic compositions is usually based on the particles’ packing optimization allied to the used of additives, that control the rheological behavior of the matrix components due to modifications in the surface chemistry of the finer particle size fractions2. As a result, important improvements in the castables’ properties could be obtained, such as higher