Investigating the effect of different binders on Alumina-spinel castable refractory

Abstract

Al2O3-spinel castable refractory has many advantages, such as high refractoriness, high resistance to chemical attack, and high mechanical strength, so Al₂O₃-spinel castable refractory is widely used in the steel ladle linings below the slag line. In this study, the effect of different binders on Alumina-spinel castable refractory was investigated. Three different sol systems, including alumina, spinel, and silica sol, were separately used as a bonding agent in alumina-spinel-based ultra-low cement castable refractory. The phase composition, microstructure, and mechanical properties of castable refractories, such as bulk density, apparent porosity, and cold compressive strength have been evaluated. In the end, the properties of the castables with sol-gel bonding were compared with those with hydraulic bonding (calcium aluminate cement). It was observed that the castables containing silica sol resulted in higher cold compressive strength (2103 kg/cm²) and higher bulk density due to the absence of low melting or eutectic phases and formation of the mullite phase.