Silicon carbide brick is a refractory material made of SiC as the main raw material. Mohs hardness 9. It is more stable for acid slag. Containing SiC 72% ~ 99%. The bricks are divided into clay binding, Si3N4 binding, Sialon binding, -SIC binding, Si2ON2 binding and recrystallization. It is mainly used in retort, cast aluminum mold, electric furnace lining and heat exchanger, etc. The formula of coarse, medium and fine SiC should be 5:1:4. The raw material for making silicon carbide bricks is generally black SiC. Its chemical composition is as follows: SiC 98.0%, free C 0.5%, Fe 0.2%, and free SiO2 0.6%. Due to the different combination methods, there are differences in the process.
Silicon nitride bonded silicon carbide bricks Silicon nitride bonded silicon carbide bricks have good alkali corrosion resistance, molten cryolite wettability, oxidation resistance, wear resistance, high thermal conductivity, thermal shock resistance and extremely low electrical conductivity. Silicon nitride combined with silicon carbide bricks are mainly used as the lining of the lower furnace body of the blast furnace, which is more than twice as long as the use of traditional refractory materials. In addition, it can be used as the lining of aluminum reduction electrolyzers and ceramic kiln furniture, which can save energy, increase life It can also be used as a blast furnace tuyere water-cooled pipe sleeve brick because of its advantages such as environmental pollution. Clay bonded silicon carbide brick. Clay-bonded silicon carbide brick is a refractory product made of silicon carbide as the main raw material and clay as a binder. It is characterized by high thermal conductivity, low thermal expansion coefficient, good thermal shock resistance and wear resistance. It is the earliest developed type of silicon carbide bricks. Clay bonded silicon carbide bricks use black silicon carbide as the raw material. Its chemical composition: SiC 98.0%, free C 0.5%, Fe 0.2%, and free SiO2 0.6%. Soft clay and pulp waste liquid with good bonding properties are used as binders. In the past, the proportion of bonded clay used was relatively large, generally 10% to 15%, and now 3% clay and 5% pulp waste liquid are used. The thermal conductivity of silicon carbide bricks with a small amount of clay added is 3 to 4 times higher than that of silicon carbide bricks combined with more clay, and the load softening temperature and slag resistance are also higher. The manufacturing process of clay-bonded silicon carbide bricks with 3% bonded clay is to prepare coarse, medium and fine SiC according to the particle gradation that can obtain the maximum bulk density. Dry mixed uniformly first, then add clay, dry mixed for 3 minutes, add 4% pulp waste liquid (density 1.26～1.289/cm3), and mix. The water content of the mud is about 1.5%. After 12 hours of trapping, the mud is passed through a 4mm screen and formed by a brick press. The brick volume density is 2.5～2.79/cm3. Dry for 2 to 4 days under natural drying conditions and fire in a tunnel kiln at a firing temperature of 1400°C. The product is used as ceramic kiln furniture (shelf, support, sagger, etc.), muffle cover for muffle furnace, lining brick for aluminum refining furnace, distillation tank for zinc distillation furnace, cement rotary kiln cooler, etc
Silicon nitride bonded silicon carbide brick Silicon nitride bonded silicon carbide brick is a refractory product made by nitriding and firing using SiC and Si powder as raw materials. Its characteristic is Si3N4 as the binding phase. Si3N4 exists between SiC crystal grains as needle-like or fibrous crystals, and is an important new refractory material. Using the principle of reaction sintering, the SiC green body containing silicon powder is sintered by the nitridation reaction, and the firing process is completed in a closed furnace with nitrogen gas and easy control. The temperature, pressure and atmosphere in the furnace must be strictly controlled. Main process parameters: nitriding gas pressure 0.02～0.04MPa, furnace atmosphere containing O2 less than 0.01%, final nitriding temperature 1350～1450℃, total nitriding time varies with product shape and size. Silicon nitride bonded silicon carbide bricks have good alkali corrosion resistance, molten cryolite wettability, oxidation resistance, wear resistance, high thermal conductivity, thermal shock resistance and extremely low electrical conductivity. Silicon nitride combined with silicon carbide bricks are mainly used as the lining of the lower furnace body of the blast furnace, which is more than twice as long as using traditional refractory materials. In addition, it can be used as the lining of aluminum reduction electrolytic cells and ceramic kiln furniture. It can also be used as a blast furnace tuyere water-cooled pipe sleeve brick because of its advantages such as environmental pollution. Silicon nitride bonded silicon carbide bricks have good alkali corrosion resistance, molten cryolite wettability, oxidation resistance, wear resistance, high thermal conductivity, thermal shock resistance and extremely low electrical conductivity. Silicon nitride combined with silicon carbide bricks are mainly used as the lining of the lower furnace body of the blast furnace, which is more than twice as long as the use of traditional refractory materials. In addition, it can be used as the lining of aluminum reduction electrolyzers and ceramic kiln furniture, which can save energy, increase life It can also be used as a blast furnace tuyere water-cooled pipe sleeve brick because of its advantages such as environmental pollution.
Features and application
Silicon carbide Plates have high thermal conductivity, good wear resistance, thermal shock resistance, and corrosion resistance. Therefore, silicon carbide bricks are widely used in industry. It can be used for metallurgical steel cylinder lining, nozzle, plug, blast furnace bottom and hearth, heating furnace without water-cooled slide rail; non-ferrous metal smelting distiller, distillation tower tray, electrolytic tank side wall, smelting metal crucible; silicic acid Sheds and muffle materials for kilns in the salt industry; oil and gas generators and organic waste combustion furnaces in the chemical industry; kiln furniture for high-tech ceramics; aluminum electrolytic cell linings, molten aluminum pipes and kiln furniture for ceramic kilns, large and medium-sized blast furnaces Lower body, furnace waist and belly, aluminum refining furnace lining, zinc distillation tank lining, etc.
