What is Silica Brick?​

As a Refractory Brick Manufacturer, share it with you.

Silica brick is an acid refractory material with good resistance to acid slag erosion. Its softening temperature under load is as high as 1640～1670℃, and its volume is relatively stable under high temperature for long-term use.

Glass Kiln Silica Brick

An acidic refractory material mainly composed of tridymite, cristobalite and a small amount of residual quartz and glass phase.

The silica content is above 94%. The true density is 2.35g/cm3. It has resistance to acid slag erosion. Higher high temperature strength. The starting temperature of load softening is 1620～1670℃. It will not deform after long-term use at high temperature. Low thermal shock stability (1~4 times of heat exchange in water) Natural silica is used as raw material, and a proper amount of mineralizer is added to promote the conversion of quartz in the body to tridymite. Slowly fired at 1350～1430℃ in reducing atmosphere. When heated to 1450℃, there will be about 1.5~2.2% of the total volume expansion. This residual expansion will make the cut joints tightly and ensure that the masonry has good air tightness and structural strength.

The mineral phase composition of silica bricks is mainly tridymite and cristobalite, with a small amount of quartz and vitreous. Tridymite, cristobalite, and residual quartz have large changes in volume due to changes in crystal form at low temperatures, so the thermal stability of silica bricks at low temperatures is very poor. During use, slowly heat and cool below 800°C to avoid cracks. Therefore, it is not suitable to be used on kilns with sudden temperature changes below 800°C.

The properties and technological process of silicon bricks are closely related to the crystalline transformation of SiO2. Therefore, the true specific gravity is an important quality indicator of silicon bricks. The general requirement is below 2.38, and the high-quality silica brick should be below 2.35. The true specific gravity is small, reflecting the large amount of tridymite and cristobalite in the brick, and the small amount of residual quartz, so the residual linear expansion is small, and the strength decline during use is also small. There are seven crystalline variants and one amorphous variant of silicon dioxide. These variants can be divided into two categories: the first type of variants are quartz, tridymite and cristobalite, their crystal structure is very different, and the transformation between each other is very slow; the second type of variants is a subspecies of the above variants ──αβ and γ type, their structure is similar, the mutual transformation is faster.

Our company also sells Glass Kiln Silica Brick, welcome to contact us.