Sic Firebrick refers to products with a SiO2 content of more than 93%. Silica bricks are made from silica with a SiO2 content of not less than 96%, adding mineralizers and binders, and going through processes such as mixing, molding, drying, and firing. The higher the SiO2 content in the silica raw material, the higher the refractoriness of the product. There are many varieties of Sic Firebrick, which are divided into: silica bricks for coke ovens, silica bricks for hot blast furnaces, silica bricks for electric furnaces, Sic Firebrick for glass kilns, etc. According to the transformation, it is divided into: standard bricks, ordinary bricks, special-shaped bricks and special-shaped bricks.
Silica brick features:
Silica brick is an acid refractory material, which has strong resistance to acid slag or acid solution erosion. The high softening temperature under load is an excellent characteristic of Sic Firebrick, which is generally 1640-1680°C.
Silica brick application:
Silica bricks are mainly used for the carbonization chamber, combustion chamber and partition walls of masonry coke ovens, glass pool kilns and kiln roofs, pool walls, high temperature load-bearing parts of hot blast stoves, glass pool kilns, pool walls, high temperature load-bearing parts of hot blast stoves, Thermal kilns such as carbon roasters.
Sic Firebrick is a refractory product with silica as the main component and its content is more than 93%. It uses quartzite as raw material, adds a small amount of mineralizer, and is fired at high temperature. Its mineral composition is a complex structure of tridymite, cristobalite, a small amount of residual quartz and vitreous formed at high temperature.
Silica brick is an acidic refractory material, which has strong resistance to acid slag erosion, but is strongly eroded by alkaline slag, and is easily damaged by oxides such as Al2O3, K20, Na2O, etc. It has good resistance to oxides such as CaO, FeO, Fe2O3. resistance.
Silica brick is an acid refractory material, which has strong resistance to acid slag erosion, but is strongly eroded by alkaline slag, and is easily damaged by oxides such as Al 203, K20, Na2O, etc. good resistance.
The high deformation temperature under load is an excellent characteristic of Sic Firebrick. The melting point (1670°C, 1713°C) close to tridymite and cristobalite fluctuates between 1640 and 1680°C. As quartz continues to transform, an irreversible volume expansion will occur. The volume of silica bricks is stable in the range from 300°C to close to the melting point (tridymite or cristobalite). When heated to 1450°C, the total volume expansion of about 1.5% to 2.2% will cause the bricks to expand. The seams are tightly sealed to ensure that the masonry body has good air tightness and structural strength.
The biggest disadvantage of Sic Firebrick is its low thermal shock stability (about 14 times of heat exchange in water), followed by its low refractoriness (generally between 1690 and 1730 °C), which limits its application range.
Silica bricks are mainly used in coke ovens, glass melting furnaces, acid steelmaking furnaces and other thermal equipment.
When using Sic Firebrick, you should pay attention to the following two points:
1. At 200~300°C and 573°C, the volume of siliceous products expands abruptly due to the transformation of crystal form. Therefore, it is not advisable to heat up too fast below 600°C in the oven, and avoid severe heat when it is cooled to below 600°C. temperature change.
2. It should not be in contact with alkaline slag as much as possible.
