Magnesite is calcined at high temperature from magnesite, bischofite or magnesium hydroxide extracted from seawater. Dicalcium Fused magnesia , which is the general name of products from magnesite and other magnesia materials to sintering process after high temperature treatment. Magnesia produced by one-step or two-step calcination process with high-temperature equipment such as shaft kiln and rotary kiln, using natural magnesite as the material is called sintered magnesia; Seawater magnesia is made by extracting magnesium oxide from seawater after magnesite and other materials are melted in an electric arc furnace and cooled in a molten state. Fused magnesia

Magnesia is one of the materials of refractory materials, which is used to manufacture various magnesia bricks, magnesia alumina bricks, ramming materials, furnace repair materials, etc., and those with more impurities are used to pave the bottom of the steelmaking furnace. High purity magnesite is produced by flotation purification of natural magnesite ore, light burning, fine grinding, ball temperature oil shaft kiln calcination. It is an indefinite refractory material for brick making.

The properties of magnesia are divided into chemical properties and physical properties. The chemical properties of magnesia mainly refer to that magnesia is mainly composed of periclase MgO. periclase is one of the common minerals in cement cooking. periclase can coexist with the four main minerals C3S, C2S, C3A and AF in cement cooking. Therefore, periclase has good corrosion resistance for cement clinker.

The physical properties of magnesia refractories in cement rotary kilns often show the following phenomena:

Periclase has a high melting point, so many magnesia refractories have good properties;

Magnesite has good thermal conductivity. When high MgO refractory materials are used and the kiln skin cannot be hung, the surface temperature of the kiln body will rise. At this time, not only the heat dissipation will be lost greatly, but also the cylinder will be simply burned out

The high coefficient of thermal expansion of periclase results in the lack of thermal shock resistance of magnesia refractories.