Magnesite has a chemical composition of MgCO3, and when it is heated it will dissociate into MgO and CO2. MgO has an extremely high melting temperature, and that makes it a good refractory material in many steelmaking, metallurgical, and ceramic processes. MgO is one of the most commonly used materials for making the bricks used to line kilns, industrial ovens, and blast furnaces. MgO is also used to make fertilizers, magnesium chemicals, and refined into magnesium metal.
