Magnesia-Carbon Refractories: Engineering MgO-C Bricks for Slag Resistance, Thermal Shock, and Campaign Life
Magnesia-carbon refractory, usually written as MgO-C refractory or magnesia carbon brick, is a basic carbon-bonded composite used where molten steel, basic slag, thermal cycling, mechanical impact, and oxidizing practice meet. Its design is built on a productive tension: magnesia provides a refractory, basic oxide skeleton with useful compatibility against basic slag, while graphite and the carbon bond reduce wetting and help the material survive thermal shock. Carbon also creates the material’s central vulnerability. When graphite and carbon bonding oxidize, the brick becomes more open, slag penetration becomes easier, and the original corrosion resistance can collapse. Successful MgO-C selection is therefore a zone-specific balance of raw materials, carbon level, antioxidant package, binder, microstructure, steelmaking practice, and maintenance.