The high temperature resistance limit of refractory bricks varies depending on their material and composition, and can be used for a long time in high temperatures ranging from over 1000 degrees to over 2000 degrees. The following are the high temperature resistance of different types of refractory bricks:
1, Clay brick
The fire resistance is 1580-1750 ℃, and the allowable temperature for use in the combustion chamber is above 1400 ℃. When used as lining material, furnace wall, furnace bottom, flue, etc., the temperature should be below 1250 ℃.
2, Crystalline silica brick
The refractory temperature is 1730-1770 ℃.
3, Silicon brick
Containing over 93% SiO ₂, it can withstand temperatures up to 2000 ℃ and is mainly used for building coke ovens. It is also used for the arch roofs and other load-bearing parts of various thermal kilns for glass, ceramics, carbon calcination furnaces, and refractory bricks. However, it is not suitable for use in thermal equipment with temperature fluctuations below 600 ℃.
4, High alumina refractory brick
High alumina bricks are used in areas of general furnaces that are resistant to high temperatures and wear, or in masonry with high loads, burner bricks, and masonry with special requirements. The dome of the high-temperature zone of the combustion chamber allows for a temperature range of 1300-1650 ℃.
General corundum bricks (a type of high alumina brick with an AL ₂ O ∝ content of not less than 90%) are suitable for lining the fire surface of heavy oil gasifiers with a working pressure of less than 3MPa, important parts of the furnace lining for burning salt containing wastewater, and radiation burner bricks working at high temperatures. The operating temperature is below 1600-1670 ℃.
Low silicon fused alumina (high alumina brick related products) is suitable for applications with strong reducing atmosphere, high hydrogen pressure, and the presence of high-temperature water vapor, such as large synthetic ammonia plants, gas collection pipe lining of the first stage converter, and lining bricks and high-temperature furnace lining of the second stage converter. The operating temperature is below 1600-1670 ℃.
5, Lightweight high alumina brick
Used for heat-resistant linings with working temperatures below 1350 ℃, and can also be used for masonry without high-temperature molten material erosion and scouring effects, and can be directly in contact with flames.
6, Lightweight alumina products (such as lightweight corundum bricks)
The operating temperature is below 1400 ℃.
7, Silicon carbide refractory brick
The use temperature is below 1400-1600 ℃, with good thermal conductivity, thermal stability, resistance to reducing atmospheres, and high strength. It is often used as a heat-resistant, wear-resistant lining, and in situations where good thermal stability, thermal conductivity, and resistance to reducing atmospheres are required.
8, Magnesia refractory brick
Using magnesite as the raw material and periclase as the main crystal phase, with MgO content of over 80% -85%, it is mainly used in open hearth furnaces, oxygen converters, electric furnaces, and non-ferrous metal smelting. However, there is no clear limit value for high temperature resistance, but its use indicates that it can withstand higher temperatures.