Why do firebricks fire

Only know that firebrick is a product used at high temperatures but do not know why it can fire, and the use of firebrick as a fireproof brick, these are not correct, the key factor of firebrick fire resistance is in its own raw materials, the use of inorganic non-metallic mineral raw materials so high temperature resistance.

Why can firebrick fire? This problem is not well understood by many people, who think that firebrick is a product that can be used at a high temperature of 1700 degrees, in fact, it is only one-sided. The main reason for the fire resistance of refractory bricks is that the mineral elements in the raw material are formed by liquid phase transformation during sintering, and the high-temperature resistant crystalline phases such as: aluminum-silicon refractory bricks will be formed during high temperature sintering, quartz phase 1470~1600℃, corundum phase 2050℃ and mullite phase 1870℃. For example, basic brick magnesia products magnesia carbon brick in the high temperature sintering process will form magnesia 2800℃ and so on.

Let's take the common high aluminum brick, high aluminum brick raw material bauxite it contains mineral elements mainly kaolinite (AL2O3·2SiO2·2H2O), diaspore (a-AL2O3·H2O) and tridiaspore (r-AL2O3·3H2O), mainly. Among them, kaolinite will lose water and change into primary mullite phase at 1350℃ in sintering, and the melting point and phase transition temperature are 1750~1787℃, diaspore will lose water and transform into a-AL2O3 corundum phase at the sintering temperature of 530~600℃, and tridiaspore will lose water and transform into a-AL2O3 corundum phase at the sintering temperature of 900~1200℃. a-LAO23 Corundum melting point at 2050℃. So it can withstand high temperature and fire resistance.