Ceramics-Silikáty 49 (2) 97-103 (2005)

THE PROPERTIES OF A LOW CEMENT CASTABLE CONTAINING CHEMICALLY PREPARED HYDROUS SPINEL

S. Mukhopadhyay, T. N. Sen, SK. M. Hassan, P. Pal

Magnesium aluminate gel precursor has been synthesized by rapid co precipitation technique at a relatively low temperature. This gel exhibits the evolution of spinel phase at significantly lower temperature than solid state sintering; however it is associated with secondary phase like corundum and periclase at higher temperature. The gel has been incorporated in different concentration 0.5-4.0 wt.% to a high alumina based castable to fabricate in situ spinel-alumina monolithic refractory. Uncontrolled agglomeration and an enormous amount of -OH,-NH₂ and C=O groups associated with the precursor gel indicates a serious apprehension about the performance of the castable. Nevertheless an optimum amount of 2.0 wt.% of spinel gel renders a satisfactory role towards the physical properties of the castable. The microsilica content of the original batch should be reduced to eliminate the detrimental CaO-Al₂O₃-SiO₂ phase generated in the matrix.

Keywords: Co-precipitation, Spinel, Castable refractory