What are the basic refractory bricks?

　　There are many types of alkaline refractory bricks. Today, we will introduce in detail the general products for concrete kilns, such as general magnesia chrome bricks, semi-immediate fusion magnesia chrome bricks, immediate fusion magnesia chrome bricks, special magnesia chrome bricks, low chromium magnesia chrome bricks, magnesia Iron spinel bricks and magnesia-aluminum spinel bricks are introduced in detail in many aspects.

　　Chemical properties of alkaline refractory bricks

　　Alkaline refractory bricks withstand the chemical attack of high-temperature kiln materials and alkali-sulfur compounds in the flue gas in the kiln.

　　1. Alkali erosion

　　Alkaline salt gas is stored in the kiln gas in an oxidizing atmosphere, which corrodes the magnesia-chrome brick and volatilizes CrO3. The brick structure becomes brittle and damaged on the hot surface of the magnesia-chrome brick, while the cold surface at 976℃~1071℃, the yellow alkali The chromium salt deposition changes the physical properties of the refractory brick body, which may cause damage to the brick body in severe cases.

　　Generally speaking, the alkali corrosion resistance of magnesia-aluminum spinel is much higher than that of chromium, but under the action of a high content of excess alkali, alkali and magnesia-aluminum spinel also play a role, generating alkali-aluminum compounds and MgO, which damage the lining bricks.

　　High-grade spinel magnesia bricks made of synthetic sintered magnesia are particularly sensitive to reducing atmospheres.

　　When calcining industrial waste fuels, due to the influence of fuel and particle size, oxidation-reduction conditions are prone to occur during the calcination process, causing frequent changes in the composition of the refractory lining, and frequent expansion and contraction of its volume, eventually causing the brick body to peel off damage.