Classification of refractory castables
2024-07-12 09:57:34
Refractory castables are a common refractory material. They are widely used in high-temperature industrial fields such as metallurgy, petrochemicals, and electricity because of their simple molding process, convenient construction, and good high-temperature resistance. According to different classification standards, refractory castables can be divided into many types. This article will classify and introduce refractory castables in detail from the aspects of material, use, binder, construction process, etc.
Classification by material
High-alumina castables: mainly high-alumina bauxite clinker as aggregate and powder, containing a high proportion of alumina (Al₂O₃). High-alumina castables have high refractoriness and good thermal shock resistance, and are suitable for working linings of high-temperature furnaces and kilns, such as electric furnace tops and ladle linings.
Corundum castables: using electric fused corundum or sintered corundum as the main raw materials, containing more than 90% alumina. Corundum castables have extremely high refractoriness and corrosion resistance, and are often used in high-temperature and highly corrosive environments, such as steelmaking furnaces and glass melting furnaces.
Silicon carbide castable: The main component is silicon carbide (SiC), which has excellent thermal conductivity and wear resistance, and is suitable for the lining of high-temperature kilns, such as cement kilns, lime kilns, etc.
Clay castable: Clay clinker is the main raw material, and the alumina content is low, generally 30%-48%. Clay castable has moderate refractoriness and relatively low price, and is often used for the working lining of medium and low temperature industrial furnaces.
Siliceous castable: Mainly made of quartz sand or silica, it contains a high amount of silicon dioxide (SiO₂). Siliceous castable has good volume stability at high temperature and is often used in glass melting furnaces and ceramic kilns.
Classification by use
Ordinary refractory castable: Used for the lining of general industrial furnaces, such as heating furnaces, annealing furnaces, etc. It requires moderate refractoriness and convenient construction.
Wear-resistant refractory castable: Used for parts that are severely worn at high temperatures, such as preheaters and cyclone separators of cement kilns. Requires excellent wear resistance.
Anti-penetration refractory castables: used in areas that are severely chemically eroded at high temperatures, such as the lining of metallurgical furnaces. Requires excellent permeability resistance and corrosion resistance.
Insulating refractory castables: used as insulation layers for high-temperature equipment, such as the insulation layers of heating furnaces. Requires good thermal insulation and low thermal conductivity.
Classification by binder
Cement-bonded refractory castables: with refractory cement as a binder, it has a fast hardening speed, high strength, and convenient construction. Commonly used in the linings and refractory prefabricated parts of various industrial furnaces.
Waterglass-bonded refractory castables: with waterglass as a binder, it has good resistance to chemical erosion. Commonly used in high-temperature areas with acidic atmosphere or acidic slag erosion.
Phosphate-bonded refractory castables: with phosphoric acid or phosphate as a binder, it has high refractoriness and high strength. Suitable for areas with high temperature and high strength requirements, such as blast furnace iron ditch, etc.
Resin-bonded refractory castables: With resin as a binder, it has a fast hardening speed and high strength. It is often used to manufacture refractory prefabricated parts and repair materials.
Application of refractory castables
Refractory castables are widely used in high-temperature industrial fields.
Metallurgical industry: used for linings of blast furnaces, converters, electric furnaces, ladles, iron ladles and other equipment, with excellent high temperature resistance, corrosion resistance and anti-permeability.
Petrochemical industry: used for linings of high-temperature equipment such as cracking furnaces, converters, heating furnaces, etc., requiring good thermal shock resistance and chemical erosion resistance.
Power industry: used for linings of high-temperature equipment such as power plant boilers and combustion chambers, with good high temperature resistance and wear resistance.
Building materials industry: used for linings of high-temperature equipment such as cement kilns, lime kilns, glass kilns, etc., requiring good high temperature resistance, anti-permeability and anti-wear performance.
Other fields: such as high-tech fields such as aerospace and military industry, also need to use refractory castables to manufacture various high-temperature equipment and materials.
Conclusion
Refractory castables, as an important refractory material, have received extensive attention and attention due to their excellent performance and broad application prospects. By rationally selecting and using refractory castables, the service life and operating efficiency of high-temperature equipment can be effectively improved, production costs can be reduced, and important economic and social benefits can be achieved. In practical applications, the appropriate type of castable should be selected according to specific working conditions, and the construction process should be strictly controlled to ensure the use effect of refractory castables.
Classification by material
High-alumina castables: mainly high-alumina bauxite clinker as aggregate and powder, containing a high proportion of alumina (Al₂O₃). High-alumina castables have high refractoriness and good thermal shock resistance, and are suitable for working linings of high-temperature furnaces and kilns, such as electric furnace tops and ladle linings.
Corundum castables: using electric fused corundum or sintered corundum as the main raw materials, containing more than 90% alumina. Corundum castables have extremely high refractoriness and corrosion resistance, and are often used in high-temperature and highly corrosive environments, such as steelmaking furnaces and glass melting furnaces.
Silicon carbide castable: The main component is silicon carbide (SiC), which has excellent thermal conductivity and wear resistance, and is suitable for the lining of high-temperature kilns, such as cement kilns, lime kilns, etc.
Clay castable: Clay clinker is the main raw material, and the alumina content is low, generally 30%-48%. Clay castable has moderate refractoriness and relatively low price, and is often used for the working lining of medium and low temperature industrial furnaces.
Siliceous castable: Mainly made of quartz sand or silica, it contains a high amount of silicon dioxide (SiO₂). Siliceous castable has good volume stability at high temperature and is often used in glass melting furnaces and ceramic kilns.
Classification by use
Ordinary refractory castable: Used for the lining of general industrial furnaces, such as heating furnaces, annealing furnaces, etc. It requires moderate refractoriness and convenient construction.
Wear-resistant refractory castable: Used for parts that are severely worn at high temperatures, such as preheaters and cyclone separators of cement kilns. Requires excellent wear resistance.
Anti-penetration refractory castables: used in areas that are severely chemically eroded at high temperatures, such as the lining of metallurgical furnaces. Requires excellent permeability resistance and corrosion resistance.
Insulating refractory castables: used as insulation layers for high-temperature equipment, such as the insulation layers of heating furnaces. Requires good thermal insulation and low thermal conductivity.
Classification by binder
Cement-bonded refractory castables: with refractory cement as a binder, it has a fast hardening speed, high strength, and convenient construction. Commonly used in the linings and refractory prefabricated parts of various industrial furnaces.
Waterglass-bonded refractory castables: with waterglass as a binder, it has good resistance to chemical erosion. Commonly used in high-temperature areas with acidic atmosphere or acidic slag erosion.
Phosphate-bonded refractory castables: with phosphoric acid or phosphate as a binder, it has high refractoriness and high strength. Suitable for areas with high temperature and high strength requirements, such as blast furnace iron ditch, etc.
Resin-bonded refractory castables: With resin as a binder, it has a fast hardening speed and high strength. It is often used to manufacture refractory prefabricated parts and repair materials.
Application of refractory castables
Refractory castables are widely used in high-temperature industrial fields.
Metallurgical industry: used for linings of blast furnaces, converters, electric furnaces, ladles, iron ladles and other equipment, with excellent high temperature resistance, corrosion resistance and anti-permeability.
Petrochemical industry: used for linings of high-temperature equipment such as cracking furnaces, converters, heating furnaces, etc., requiring good thermal shock resistance and chemical erosion resistance.
Power industry: used for linings of high-temperature equipment such as power plant boilers and combustion chambers, with good high temperature resistance and wear resistance.
Building materials industry: used for linings of high-temperature equipment such as cement kilns, lime kilns, glass kilns, etc., requiring good high temperature resistance, anti-permeability and anti-wear performance.
Other fields: such as high-tech fields such as aerospace and military industry, also need to use refractory castables to manufacture various high-temperature equipment and materials.
Conclusion
Refractory castables, as an important refractory material, have received extensive attention and attention due to their excellent performance and broad application prospects. By rationally selecting and using refractory castables, the service life and operating efficiency of high-temperature equipment can be effectively improved, production costs can be reduced, and important economic and social benefits can be achieved. In practical applications, the appropriate type of castable should be selected according to specific working conditions, and the construction process should be strictly controlled to ensure the use effect of refractory castables.