Magnesia chrome brick

Production process

The production process of magnesia chrome bricks is similar to that of magnesia bricks. In order to eliminate the influence of MgO, Cr2O3, Al2O3 or

Direct bonded magnesia chrome brick

The loose effect caused by the expansion of iron oxide reaction to produce spinel can also be made into magnesia chrome bricks by using synthetic 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 bricks is simple, the cost is low, and the thermal stability is good, but the high temperature strength is far less than that of fired bricks. In the late 1950s, a so-called "direct bonding" magnesia chrome brick was developed. This brick is characterized by pure raw materials, high firing temperature, direct combination between high temperature phases such as periclase and spinel, and island distribution of low melting phases such as silicate. Therefore, the high temperature strength and slag resistance of the brick are significantly improved.

It is an effective measure to eliminate the loose effect by using the fine powder made by grinding and calcining the compact of chrome ore magnesia and mixing it with the coarse grains of magnesia to make bricks. Compared with ordinary magnesia chrome bricks, the magnesia chrome bricks made by this method have lower porosity, higher compressive strength, load softening temperature and flexural strength. The magnesia chrome brick made of chrome ore magnesite powder compact and calcined magnesia chrome sand at high temperature has better slag resistance and high temperature strength than other magnesia chrome bricks.

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