A basic brick of fused or sintered magnesia with roughly 5 to 25 percent flake graphite, bonded with resin and tempered rather than fired, with metallic antioxidants such as aluminum or silicon. The graphite resists wetting by slag and gives excellent thermal shock resistance and conductivity. Its main enemy is oxidation of the carbon by air or iron oxide, which leaves a weak, porous magnesia layer that slag then washes away.
Slag line gets the 14 percent carbon magnesia-carbon brick, the walls below can drop to 10.
Idle time kills mag-carbon. A hot, empty ladle breathing air burns the carbon out of the hot face between heats.
Also heard as
- mag-carbon
- mag-carb
- MgO-C
Related terms
Basic refractory
Refractory based on magnesia, lime or dolomite that resists basic slags with high lime-to-silica ratios.
Slag line
Band of a ladle or furnace lining where the slag layer floats on the metal, usually the fastest-wearing zone.
Dead-burned magnesia
Magnesia fired so hard it barely reacts with water, the main raw material of basic refractories.
Mag
Clipped shop word for magnesia, magnesia brick or a magnesia-based mix.