Effects of Spinel, Silica and Cement on Properties of Alumina-Magnesia Castable

摘要

In spite of having excellent corrosion resistance, in situ spinel forming alumina - magnesia (AM) based high alumina castables suffer from poor hot load properties. This deficiency is fallout of generation of liquid phase in the matrix, which is required to facilitate spinel formation and controlling associated expansion. The present work reports the effect of partial substitution of magnesia by pre-formed spinel in AM- castable and simultaneous decrease of liquid phase (through reduction of silica content) on hot load and slag resistance characteristics. Effect of cement content on above characteristics has also been studied. It is found that partial substitution of in situ spinel by pre-formed spinel, reduction of silica and increase of cement content substantially improve hot strength without much deterioration of corrosion resistance. The findings are presented in respect of hot strength, linear change, porosity, XRD analysis, EPMA and qualitative slag corrosion resistance of different compositions after firing.