What is magnesia? Reburned magnesite
Magnesite is calcined at high temperature from magnesite, bischofite or magnesium hydroxide extracted from seawater. It is a general term for the products of magnesite and other magnesia raw materials that have been treated at high temperature to reach the sintering process. Magnesite sintered from natural magnesite is made by one-step or two-step calcination process with high-temperature equipment such as shaft kiln and rotary kiln; Seawater magnesia is produced by extracting magnesium oxide from seawater after magnesite and other raw materials are melted in an electric arc furnace and cooled.
Magnesite is one of the most important raw materials for refractories, which is used to manufacture various magnesia bricks, magnesia alumina bricks Ramming material , furnace mending materials, etc., which contain more impurities, are used to pave the bottom of the steelmaking furnace, etc.
The high-purity magnesite is produced by flotation purification of natural super grade magnesite ore, light burning, fine grinding, ball pressing and ultra-high temperature oil shaft kiln calcination. It is a high-quality raw material for brick making refractory.
Medium grade magnesia is produced from light burned magnesia with 97% MgO as raw material by pressing ball and calcining in high temperature shaft kiln. The product has good sintering degree and dense crystallization. It is a high-quality raw material for producing medium grade magnesia refractory products.
Fused magnesia It is made by melting selected special A grade natural magnesite or high-purity light burned magnesium particles in an electric arc furnace. This product has the characteristics of high purity, large crystal grain, compact structure, strong slag resistance, good thermal shock stability, is an excellent high temperature electrical insulation material, and is also an important raw material for making high-grade magnesia bricks, magnesia carbon bricks and amorphous refractories.
Raw materials for magnesia production
The main raw material for producing magnesia refractories is magnesia, which refers to sintered magnesia with a certain particle composition. It is broken from sintered magnesite. Sintered magnesite can be obtained by calcining magnesite.
In addition, sintered magnesite can also be extracted from seawater, salt lake brine, dolomite, serpentine and brucite. But so far, sintered magnesite in China is mainly obtained by calcining natural magnesite, and the magnesium extraction project in salt lake is still under construction.
The production of fused magnesia in China is mainly concentrated in Liaoning and Shandong, and magnesite is the main ore.