Four different binders for high alumina castable: A comparative study

Abstract Four different binders, namely, calcium aluminate cement, silica sol, hydratable alumina (HA), and mono‐aluminum phosphate, are used separately in a high alumina castable composition to compare their effects on the properties development. The castables were prepared using commercial‐grade materials using a distribution coefficient of 0.23, as per the Dinger and Funk model. Cement‐bonded castable was added with additives, like flow modifier (fume silica), deflocculant, and anti‐setting agent, and HA‐bonded castable was added with deflocculant. All the castables with different bonding systems were processed as per conventional manufacturing technique and heat treated at three different temperatures. The castables showed corundum as the major phase post‐firing with a minor anorthite phase for a cement‐bonded one and a mullite phase for the silica sol–bonded one. Density and cold crushing strength were found to be higher for the cement‐bonded one, whereas the hot strength was higher for the HA‐bonded one, and thermal shock resistance was higher for the silica sol–bonded castable.