Effect of different boron-containing additives on the oxidation resistance of carbon–bonded magnesia bricks

Abstract

Carbon-bonded magnesia brick is widely used in iron- and steel-making processes. However, carbon in the brick is susceptible to oxidative damage, and great attention has been paid to improving the oxidation resistance of carbon-bonded magnesia brick. To study the effect of boron-containing additives on the oxidation resistance of carbon-containing refractories, carbon-bonded magnesia bricks were prepared from fused magnesia, flake graphite, and phenolic resin with three powders as additives, namely B4C, Mg2B2O5, and ZrB2. The effects of the three boron-containing additives on the properties of the carbon-bonded magnesia bricks were analyzed and compared, and the relationships between the properties, microstructure, and phase evolution were studied. The results show that an appropriate addition of the three boron-containing additives is beneficial for improving the density and cold compressive strength of the carbon-bonded magnesia bricks. Furthermore, B4C exhibits the best antioxidation performance followed by ZrB2 and Mg2B2O5.