Use of alumina dispersant in alumina‐spinel castable: Comparison between in situ and preformed spinels

Abstract

The role of alumina dispersant as a flow modifier, completely replacing fume silica, on the properties of preformed and in situ spinel‐containing low cement high alumina castables was investigated with variations in spinel content and granulometry. Both 10 and 20 wt.% spinel‐containing compositions were prepared using preformed spinel or magnesia in alumina castable compositions with vibratable and self‐flowing consistency. The castables underwent conventional processing methods and accessed for various refractory‐related parameters post‐heat treatments. No glassy phase was observed in the castables upon firing. The presence of self‐flowing consistency led to improved characteristics. Preformed spinel‐containing compositions showed improved density, strength, hot strength, and thermal shock resistance properties, whereas slag corrosion and penetration resistances were found to be higher for in situ spinel‐containing castable.