Factors for the Production of Mullite Brick

Mullite brick is made of synthetic mullite as the main raw material. It main crystal phase is mullite. Mullie brick contains 48%-90% Al2O3. 

When the Al2O3 content in the brick is lower than the theoretical content, there will be a small amount of glass phase and cristobalite in it. When the Al2O3 content in the brick is higher than the theoretical content, there are also corundum phase. 

 

So, according to the crystalline composition and the content, mullite bricks can be divided into low mullite brick, mullite brick, mullite-corundum brick and corundum-mullite brick. The price of the mullite brick is higher than that of high alumina brick and fire clay brick. 

 

The manufacturing process of mullite brick is similar to that of the high alumina brick. It is made of synthetic mullite clinker as granular materials. The fine powder is synthetic mullite clinker or mixed powder formulated with corundum, quartz powder and pure clay. The Granular materials and fine powder are mixed in proportion. The common ratio is 45%-55% granular materials and 55%-45% fine powder (<0.088mm). After uniformly mixed, the mixture is molded under high pressure. The calcination temperature is 1550-1600℃. When the clinker is granular, the firing temperature is greater than 1700℃. 

 

The purity of the raw materials, the particle size of raw materials and the firing temperature are the main factors for the manufacturing process.