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Magnesia chrome brick is mainly used in metallurgical industry, such as the construction of open hearth furnace top, electric furnace top, secondary refining furnace and various non-ferrous metal smelting furnaces. The high-temperature part of ultra-high-power electric furnace wall is made of fused cast magnesium chromium brick, the high erosion area of secondary refining furnace is made of magnesium chromium brick made of synthetic material, and the high erosion area of non-ferrous metal flash smelting furnace is made of fused cast magnesium chromium brick and magnesium chromium brick made of synthetic material. In addition, magnesia chrome brick is also used in cement rotary kiln firing zone and regenerator of glass kiln.

Production technology

The production process of fired magnesia chrome brick is similar to that of magnesia brick. In order to eliminate the loose effect caused by the expansion of spinel formed by the reaction of MgO and Cr2O3, Al2O3 or iron oxides in the firing process, magnesia chrome bricks can also be made from the synthesized common sintering materials. In addition, there are unburned magnesia chrome bricks, such as unburned magnesia chrome bricks combined with inorganic magnesium salt solution. The production process of unburned magnesia chrome brick is simple, low cost and good thermal stability, but its high temperature strength is far less than that of fired brick. In the late 1950s, a so-called "direct bonding" magnesia chrome brick was developed. This kind of brick is characterized by pure raw material, high firing temperature, direct combination of periclase, spinel and other high temperature phases, and island distribution of low melting phase such as silicate. Therefore, the high temperature strength and slag resistance of the brick are significantly improved.

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It is an effective measure to eliminate the loose effect that the fine powder produced by the co grinding of chromite and magnesia and the coarse magnesia particles are used to make bricks. Compared with the ordinary magnesia chrome brick, the magnesia chrome brick made by this method has lower porosity, higher compressive strength, load softening temperature and flexural strength. The slag resistance and high temperature strength of magnesia chrome brick made from chrome ore magnesite powder compacts and calcined magnesia chrome sand are better than other magnesia chrome bricks.

In addition, there are fused cast magnesia chrome bricks directly cast by electric arc furnace melting magnesia chrome materials (see the microstructure, see the color pictures), and the fused grains produced by the electric melting magnesium chromium materials according to the brick making process are combined with magnesium chromium bricks.