The main component of silicate brick is silicate, which will undergo polycrystalline transformation during the production process, so the expansion coefficient of silicate brick is large.

silicate bricks are characterized by high softening temperature under load, but low thermal shock stability and lower refractoriness than ordinary high alumina bricks. silicate brick has a volume expansion rate of 1.5~2.2% when the temperature is 1450℃. Even in the production of silicate brick, the mold must be properly scaled according to the expansion coefficient. Leave room for expansion to make the size of the silicate brick more accurate.

During the production of silicate bricks, the conversion between quartz, tridymite and cristobalite in the raw materials will destroy the original crystal structure and rearrange the structure. Because the activation performance is high during the firing process, the transition temperature is high but slow, resulting in a large volume expansion effect.

The solution formed at the firing temperature of the slab of silicate brick is less difficult to fire. A series of physical chemistry that occurs in the firing process of the silicate brick will increase the size of the silicate brick by about 3m.

The temperature of the silicate brick changes greatly during the firing process: the residual moisture is drained from the brick at 150℃, and it starts to decompose at 450℃; after the dehydration is completed at 450~500℃, there will be 0.82% volume expansion in the range of 550~650℃. The solid phase reaction starts between 600~700℃, and the brick strength increases. At 1100°C, the transformation rate of quartz increases, but the specific gravity of the bricks begins to decrease. At this time, the volume of the bricks increases due to the conversion of quartz to a low-density variant. In the range of 1100~1200, the silicate brick will crack.

silicate bricks produce volume changes during the heating process, under different temperature steps. The change of silicate can be divided into 600℃, 600~1100℃, 1100~1250℃ and above 1250℃. It will expand at 500~600℃. At 700~800℃, it shows microscopic shrinkage. The shrinkage will be greater at 1000~1100℃. At 1200℃, the quartz transformation will accelerate, and the green body will begin to expand violently. The extent of expansion is based on different types of raw materials to produce different expansion coefficients.

The biggest disadvantage of silicate bricks is low thermal shock stability, low refractoriness, but high softening temperature under load, which is suitable for use in kiln linings in acid atmospheres.