Thermomechanical Behavior of High-Alumina Refractory Castables with Synthetic Spinel Additions

The thermomechanical behavior of a high‐alumina refractory that contains 10 wt% of synthetic spinel has been studied. Results have been correlated with the microstructural and mineralogical evolutions using X‐ray diffraction and scanning electron microscopy, as function of the firing temperature. Dry, castable, raw‐material mixtures were sieved to 1000°C, viscoelasticity–plasticity dominated the mechanical behavior. In this case, the description was initiated by conducting load–relaxation tests, which allowed the behavior to be related to the viscous‐phase content.