Microstructures of refractory castables prepared with sol–gel additives

Several kinds of inorganic sol and gel materials were applied to high alumina based low and ultra low cement refractory castable compositions and these were fired at elevated temperature. A scanning electron microscope (SEM) study of the fired specimens was performed and the microstructural features were analysed in terms of the desirable properties of a refractory material, with an aim to elucidate the effect of sol gel additives on castables.