Why are magnesia and dolomite refractories used in steelmaking furnaces?

Magnesia and dolomite are classified as basic refractories, which are essential in steelmaking due to their chemical compatibility with the furnace environment.1

These materials are primarily used to line basic oxygen furnaces, electric furnaces, and open-hearth furnaces because they exhibit outstanding resistance to iron oxides and the basic slags generated during the steelmaking process. Their performance is further enhanced when they incorporate carbon, which is often introduced through pitch-bonding or tar-impregnation.1

In the case of dolomite refractories, the material must be impregnated with tar or pitch after burning to prevent the rehydration of the lime (CaO) component. By providing a stable, durable lining that resists chemical erosion from molten slag, these basic refractories ensure the integrity and longevity of high-temperature steelmaking vessels.1