Why is the re bonded magnesia chrome brick?

(3) Co fired magnesia chrome brick

The production process of this product is characterized by burning the mixture of magnesia and chrome ore fines with a certain proportion in a high temperature furnace, realizing the solid phase reaction for the purpose of generating secondary spinel and direct combination of magnesia and chrome ore to produce a common sintering material, which is used to manufacture fired products or chemical bonded products.

The direct bonding and homogeneity of microstructure of jointly sintered magnesia chrome bricks are better than those of directly bonded bricks. The amount of periclase dissolved phase and intercrystalline secondary spinel is more. The jointly sintered magnesia chrome bricks have a series of better properties than those of directly bonded bricks, especially known for high temperature strength, temperature resistance and slag resistance.

Common fired bricks can also be divided into two varieties. One is all common fired bricks. Particles and fine powders are all common sintered materials. The microstructure of fired or chemically bonded bricks is basically similar; The second is part of the common sintered bricks. There is a part of the ingredients, such as the common sintered material for coarse particles, while the fine powder can be mixed into the bricks with a certain proportion of fine chrome ore and magnesium sandpaper powder, so that the fired products and chemically bonded products are different in microstructure.

(4) Re bonded magnesia chrome brick

The magnesium chromium mixed powder is melted by electric melting method, and crystallized through the melt to form a raw material with a fairly uniform microstructure and a mixture of magnesium chromium spinel and periclase as the main phase. The electric melting magnesium chromium mixed material is crushed into a certain particle size, mixed and shaped, fired to prepare a rebonded brick, or directly used as a chemical bonding platform brick.

The microstructure of the rebonded brick is characterized by a high degree of direct bonding and contains a large amount of spinel dissolved phase: the basic crystal containing a large amount of dissolved phase essentially changes the physical and chemical properties of periclase, such as reducing the thermal expansion coefficient, improving the thermal shock resistance, and improving the resistance to acid alkaline slag erosion. The rebonded brick has the same properties as the fused cast brick, but has better temperature resistance and more uniform microstructure than the fused cast brick.

The combined magnesia chrome brick is a fine matrix with uniformly distributed pores and small cracks, which is more sensitive to rapid temperature change than melting and casting. The high temperature performance of the product is between the fused cast brick and the direct bonded brick.