Magnesia alumina brick refers to an alkaline refractory made of magnesia and industrial lead oxide or alumina as raw materials, crushed, shaped, and fired at about 1600°C. The refractoriness is greater than 2000 ℃, the performance of rapid cold and rapid heat resistance is better than that of magnesia brick, and it can resist the erosion of alkaline slag. It is used to build the furnace roof of steel-making alkaline open hearth furnace and electric furnace. Light burnt magnesia powder

Magnesia alumina bricks are based on periclase as the main crystal phase and magnesia alumina spinel as the matrix. They are better for thermal shock resistance than magnesia bricks. In order to improve the thermal shock resistance of magnesia bricks, fine alumina or bauxite clinker powder is introduced into the ingredients to form a magnesia-aluminum spinel matrix, thereby making magnesia-aluminum bricks. Magnesia alumina bricks are characterized by good thermal shock resistance, high load softening temperature, load softening temperature above 1580 ℃, and good glass corrosion resistance. As the content increases, the apparent porosity of the brick increases. But when the content is less than 10%, the brick is still dense, and the apparent porosity can reach 14%, generally 15% to 18%.