The Nature of Fire Clay Brick

Fire clay brick is mainly composed of mullite, cristobalite and glass phases. Their content determines the nature of fire clay brick. Refractory clay is a widespread mineral, its different origin clay

composition has big difference with impurity content. Therefore, the phase composition of fire clay brick may vary widely. As the difference between fire clay brick composition and the production

process, the nature of fire clay brick will fluctuate within a wide range.

The apparent porosity of fire clay brick is 10% -30%. The porosity of dense clay brick is low. Generally, the molding pressure of the brick is large, The porosity of fire clay brick with high sintering

temperature and high impurity content is low. However, most dense clay brick require good high-temperature performance, thus limiting the content of harmful impurities, only by controlling the

size of the composition of the mud, increasing the molding pressure and firing temperature to improve the bulk density of fire clay brick.

The refractoriness under load of fire clay brick  is 1200-1500 ℃. In general, the mullite content in the fire clay brick is greater,  the mullite grains are  the more complete, the glass phase content is

the lower and  the SiO2 content  in the glass phase is the higher, the refractoriness under load is the higher .





The thermal shock resistance of fire clay brick is better, but affected by the composition and structure have a wide range of change. 1100 ° C - the number of water-cooled is at 10-100 times

between the changes. Mullite content is high, the content of cristobalite is low, less glass phase content of fire clay brick with good thermal shock resistance is good. Clay products for the acid

refractory material, acid-resistant slag erosive is strong, is a very wide range of common refractory material, commonly used in the dry quenching furnace, heating furnace, ladle lining, aluminum

furnace and other industrial furnaces. When the clay products used in aluminum smelting furnace, Destroyed by reaction with NaF generate nepheline, therefore, to improve the Al2O3 content of

clay products, and can not extend its service life.