Modified in situ spinel-alumina castables were preparedby using 8.0 wt.% of calcined hydrated magnesium aluminate additives synthesizedvia facile sol gel and coprecipitation routes. These additives werecharacterized by particle size analysis and transmission electron microscopy.The castables prepared by them were compared in terms of bulk density, apparentporosity, cold crushing strength and spalling resistance to identify theexcellent performance of the sol gel additive having nanocrystalline feature.The quality of castable was illustrated again by comparing it with the sameprepared by commercially available spinel fines having well establishedperformance. Scanning electron microscopy, energy dispersive spectroscopy, poresize distribution and X-ray diffraction analysis were used to examine selectedfired samples. It appeared that the spinel-alumina castable prepared by the solgel additive can be a potential candidate for application in steel plants.
