Role of Nanocrystalline Spinel Additive on the Properties of Low Cement Castable Refractories

Abstract

Hydrated magnesium aluminate gel prepared via a cost-competent sol-gel route has been found to retain nanocrystals after optimum thermal treatment. The reactive gel-derived powder incorporated to the matrix of a high alumina based refractory castable upgraded its physical properties as revealed from the laboratory scale results. The performance of sol-gel spinel is better than coprecipitated spinel and almost comparable to presintered spinel powders popularly utilized by the refractory manufacturers. Attempts have been made to evaluate and analyze the better slag corrosion and thermal shock resistance properties of spinel-bonded castable by the nanocrystalline feature of the sol gel spinel. SEM, TEM, SAED, XRD, IR, and the physical properties of selected samples have been studied to understand the characteristics of the respective refractory materials.