Visit Magnesia is magnesium oxide (MgO). It is a refractory material of the Oxidic Refractory Materials (or basic), characterized by a extremely high melting point (approx. 2800∘C), making it one of the most refractory oxides commercially available.
In-depth definition : The magnesia used in refractories is produced by calcining (heating) magnesium carbonate (magnesite) or magnesium hydroxide (from seawater) at very high temperatures. The end product is Sintered magnesia (or clastic peridot), which has a very high density and excellent chemical stability. Magnesia is classified as a basic refractory, which is essential for its function: it is designed to resist slag corrosion (metallurgical residues) which are also basic in nature, a principle of chemical attack of the’Operational Excellence similar resists similar“.
Strategic Applications
Magnesia is a mainstay of heavy industry because of its resistance to the most aggressive environments:
- Steel industry : This is the main application. Magnesia or Carbon-Magnesia (Mag-Carbon) are used to coat converters (where steel is refined) and ladles. Magnesia lining is essential, as the steel slag are rich in calcium and iron oxides, which are basic and would react rapidly with an acidic coating (such as the Silica).
- Non-ferrous metallurgy : Used for smelting copper and other metals where the slag is basic in nature.
- Cement works and lime kilns : Areas subject to very high temperatures and the presence of lime (calcium oxide), another basic oxide.
Magnesia and Carbon (Mag-Carbon)
To optimize Industrial Performance and equipment life, Magnesia is often associated with the Carbon (Graphite) to create refractory bricks Mag-Carbon. This combination offers the best of both worlds:
- Magnesia: Chemical resistance to basic corrosion.
- Carbon (Graphite) : Resistance to thermal shock and penetration (non-wetting) by molten metal.
The use of Mag-Carbon in critical areas ensures a high level of longer oven life, reducing production downtime and maximizing productivity. TRS (Taux de Rendement Synthétique).
Operational challenges
The main disadvantage of pure Magnesia is its relative sensitivity to thermal shock compared with other materials such as Mulite. This is one of the reasons why, in applications subject to frequent thermal cycling (start/stop), it must be combined with the Graphite or used in the form of Monolithic refractories specialized.
In conclusion, the Magnesia is the essential basic refractory that enables the steel industry to operate at extreme temperatures while controlling chemical wear, thus guaranteeing the reliability of manufacturing processes.
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