Physical and Chemical Properties of Magnesium Aluminum Spinel Bricks

Magnesia alumina spinel brick and spinel brick are both abbreviations of periclase magnesia alumina spinel brick. In the 1980s, the Japanese invented periclase magnesia alumina spinel bricks for the cement industry, which were quickly promoted to various parts of the world after successful use. Magnesium brick supplier

Magnesium aluminum spinel brick is a new type of refractory material manufactured by replacing magnesium chromium spinel in magnesium chromium bricks with magnesium aluminum spinel. The chemical formula of magnesium aluminum spinel (MA) is MgO · Al2O3, with MgO accounting for 28.2% and Al2O3 accounting for 71.8%. Magnesium aluminum spinel belongs to the equiaxed crystal system mineral, n=1.715, hardness=8, relative density 3.55, melting point 2135, and thermal expansion coefficient of about 8.5 × 10-6K-1.

In the MgO-Al2O3 system, the solid solution of Al2O3 in periclase is about 0 at 1600; At 1800, the solid solution content was only 5%, which is much smaller than Cr2O3. In the MgO-Al2O3 system, the Binary phase of * * * is magnesium aluminum spinel. The melting point of magnesium aluminum spinel is as high as 2135, and the co melting temperature of MgO-MA is also 2050. Magnesia alumina spinel is a natural mineral commonly found in drift sand deposits, and therefore has good chemical stability to natural substances.

In summary, magnesium aluminum spinel is a refractory raw material with high melting point and low thermal expansion, which has good chemical stability to natural substances and good thermal shock stability of the refractory products produced. Compared with directly bonded magnesia chrome bricks, the advantages of periclase magnesia alumina spinel bricks lie in their strong resistance to alkali vapor, free SOX corrosion, and changes in oxidation-reduction atmosphere, without producing Cr6+that pollutes the environment. The disadvantage of periclase magnesia alumina spinel brick is its weak resistance to cement clinker erosion and poor kiln skin adhesion.