A refractory built on chemically basic oxides, mainly magnesia and lime, including magnesia, doloma, magnesia-carbon, magnesia-chrome and magnesia-spinel. Basic refractories survive basic steelmaking slags rich in lime, while acid refractories such as silica and fireclay suit acid, silica-rich slags; alumina, chrome, carbon and silicon carbide are counted as neutral. The rule of thumb is to match the lining to the slag, because a mismatch dissolves fast.
Steel slag's running a basicity of 2.5, so it's basic refractory or nothing in that zone.
Also heard as
- basic
- basic lining
- basic brick
Do not mix it up with
- Silica brick: Silica brick is the classic acid refractory; putting it against basic slag dissolves it quickly.
Related terms
Magnesia-carbon brick
Resin-bonded brick of magnesia and graphite, the workhorse lining of BOFs, electric arc furnaces and ladle slag lines.
Dead-burned magnesia
Magnesia fired so hard it barely reacts with water, the main raw material of basic refractories.
Slag attack
Chemical dissolution and penetration of a refractory by molten slag, the main wear mode in metal processing.
Silica brick
Brick of over 93 percent silica with high hot strength but sharp volume changes when cooled below red heat.