(1) Ordinary magnesia bricks can withstand high temperature heat load, fluid flow impact and chemical attack of molten steel and strong alkaline slag. Therefore, the linings of smelting furnaces that have suffered the above-mentioned functions, such as open hearth furnaces, converters, electric furnaces, iron furnaces, non-ferrous metal smelting furnaces, furnaces for soaking furnaces and heating furnaces, and cement kiln and glass kiln regenerators, etc. Such refractory products can be used for fused magnesia bricks. However, due to its poor thermal shock resistance, it should not be used in places where the temperature changes drastically. In addition, due to its high thermal expansion and low load softening temperature, it must be used for hanging on the top of a high temperature furnace.

(2) Magnesia-calcium bricks and magnesia-silica bricks can be used in the same conditions as ordinary magnesia bricks. However, due to the higher softening temperature of these products and the better performance of the magnesium-calcium bricks against alkaline slag, the magnesium-silica bricks also have the ability to resist various slags, so the scope of application is more extensive. For example, magnesia-calcium bricks are better for being attacked by alkaline slag. However, such products have poor thermal shock resistance and are prone to cracking. Magnesia-silica bricks can also be used as an open hearth furnace or a lattice brick with less temperature change in the upper part of the regenerator of a glass melting furnace.

(3) Magnesium-aluminum brick can replace ordinary magnesia brick, and it is effective for the above parts. Therefore, the product has excellent thermal shock resistance and high load softening temperature, so it can also be used in places subject to periodic temperature fluctuations, such as in the top of a flat furnace, a high temperature zone of a cement kiln, and a regenerator of a glass melting furnace. The effect is obviously better than ordinary magnesia bricks, and can also be used for other high temperature kiln furnaces such as high temperature tunnel kiln.