China's Refractories

Abstract: Microsilica-gel bonded bauxite based no-cement refractory castables (NCCs) have been produced using two readily available dispersants. These NCCs were compared to NCC with SioxX-Zero, a purposely-developed product for microsilica-gel bonded no-cement castable systems to control flow properties and setting characteristics. Three mixing and curing temperatures were applied: 5 ℃, 20 ℃ and 35 ℃. The results show that setting-behaviour and mechanical properties strongly vary with the type of dispersant and the curing temperature. However, both setting and strength are less temperature dependent in the castables with SioxX-Zero. Furthermore, the drying and firing of microsilica-gel bonded NCCs were investigated. Since microsilica-gel bond system contains only a small amount of bound water, the castables can be fired at very high heating rates, once the free water has been removed.

Key words: dispersants, setting, curing temperature, no-cement castable (NCCs), microsilica-gel bond, fast drying