Magnesia is made from magnesite, water magnesite or magnesium hydroxide extracted from sea water by high temperature calcination. It is a general term for magnesite and other magnesia materials to be sintered after high temperature treatment. The magnesia made of natural magnesite is called sintered magnesia by first calcining or two-step calcining process with high temperature equipment such as shaft kiln and rotary kiln. Magnesite and other materials by electric arc furnace melting to molten state after cooling is called the extraction of magnesia from seawater made of seawater magnesia.
Magnesia is one of the materials of refractory materials, used to manufacture all kinds of magnesia bricks, magnesia aluminum bricks, ramming materials, tinkering materials, etc., containing more impurities, used to pave the bottom of the steelmaking furnace. It is made by flotation purification of natural magnesite and calcination by light burning and fine grinding press ball warm oil shaft kiln. It is a refractory material for making bricks.
The properties of magnesia are divided into chemical properties and physical properties. The chemical properties of magnesia mainly mean that magnesia is the main component of magnesia MgO, magnesia is one of the common minerals in cement, and magnesia can coexist with four main minerals C3S, C2S, C3A and C4AF in cement. Therefore, the cementitious clinker of magnesite has good erosion resistance.
The physical properties of magnesia refractories in cement rotary kilns often show the phenomenon:
The melting point of magnesite is very high, so many magnesia refractories have quite good high temperature resistance;
Magnesite thermal conductivity is very good, the use of high MgO refractory materials, and can not be hung on the kiln skin, the surface temperature of the kiln body rises, at this time, not only the heat loss is very large, but also simply burned out the cylinder
The high coefficient of thermal expansion of magnesite leads to the lack of thermal shock resistance of magnesite refractories, which often falls off during use.
