Why do basic refractories resist iron oxides and basic slags?

Basic refractories, which include materials like magnesia, dolomite, and chrome, are chemically classified as basic because they contain alkaline-earth oxides such as lime or magnesia.1

Their ability to resist iron oxides and basic slags is fundamentally rooted in this chemical composition. In industrial metallurgy, materials are selected to be chemically compatible with the substances they contain to prevent corrosive reactions. Because these refractories are basic, they do not react aggressively with basic slags, which are also chemically basic in nature.21

Furthermore, their resistance is significantly enhanced by the addition of carbon, either as flakes or through pitch-bonding and tar-impregnation. This carbon addition helps prevent the penetration and chemical attack of the refractory by iron oxides and slag, making these materials essential for the linings of electric furnaces and basic oxygen furnaces.2