China's Refractories

Abstract: Oxidation of the added graphite and the bonding carbon is an important degradation mode of doloma-carbon refractories in service. In this work, the behavior and effects of various boron bearing materials (CaB6, ZrB2, Bc and colemanite) as antioxidants have been investigated and compared to the effect of Al-Mg alloy. For CaO-MgO-C materials, the effect of boron bearing additives is better than Al-Mg alloy. The borate melt formed at high temperature would retard or prevent carbon oxidation, thus contributing to improved oxidation resistance. Preliminary investigations on the effect of boron bearing additives and Al-Mg alloy on corrosion resistance of doloma-carbon materials have indicated that simultaneous addition of the two types of additives would lead to pronounced improvement of slag corrosion resistance.