The last article mentioned the characteristics of silicon nitride combined with silicon carbide bricks. In this article, we will talk about its application.The application is divided into four subsections, and each subsection is subdivided accordingly.
3. Applicatio
3.1 Ceramic Industry
3.1.1 Building Sanitary Ceramics Industry
At this stage, in the firing of ceramic products, most of the roller kilns are used to burn sanitary ceramics and wall and floor tiles, and the rollers of the roller kiln are basically made of silicon nitride combined with special refractory brick silicon carbide. The application of silicon nitride combined with silicon carbide rollers solves the problem of high sintering temperature and heavy load, effectively reduces product energy consumption and improves product quality.
3.1.2 Household Ceramics Industry
There are two ways of firing daily-use ceramics: one is firing in a shuttle kiln with a saggar or similar kiln furniture; the other is firing in a roller kiln, the same as the firing of building sanitary porcelain. Kiln furniture made of silicon nitride combined with special refractory brick silicon carbide can significantly reduce the mass ratio of kiln furniture to bricks, save energy and reduce consumption, and at the same time improve product quality and pass rate. The roller kiln is used to burn daily-use ceramics, and the use of silicon nitride combined with silicon carbide rollers improves the service life of the kiln.
3.1.3 Electric Porcelain and Electronic Ceramic Industry
The electric porcelain and electronic ceramic industries need kiln furniture materials with high temperature, high strength, good thermal stability, long service life and reasonable price, which provides a broad market for the application of silicon nitride combined with special refractory brick silicon carbide kiln furniture.
3.2 Metallurgical Industry
3.2.1 Aluminum, copper, zinc and other industries
High-quality silicon nitride combined with special refractory brick silicon carbide material is used instead of traditional carbon material on the side wall of the electrolytic cell. It can also be used as a temperature measuring thermowell, lining of aluminum smelting furnace, lining of “baozi” containing aluminum liquid, and crucible. , Pumps, pipes, valves, molds for casting aluminum, liquid risers for forming automobile wheel hubs, etc.
3.2.2 Steelmaking and steel rolling industry
The application of new steelmaking technology and new technology has put forward higher requirements for refractory materials for ladle. The lining of ladle has changed from the original dominant high-alumina brick to a material with better corrosion resistance, silicon nitride combined with silicon carbide. Material. It has been used in ladle successively in developed countries such as Europe and the United States, and has achieved remarkable economic benefits. The most important use of silicon nitride as a refractory material in the steelmaking industry is as a split ring for horizontal continuous casting. In addition, there are many industrial furnaces, in order to prevent the overheating and damage of some of their components, water cooling measures are often used. The best material for the water-cooled tube slide rail system is silicon nitride combined with silicon carbide bricks.
3.2.3 Ironmaking Industry
In recent years, silicon nitride combined with silicon carbide special refractory brick for blast furnaces have developed rapidly. About 61% of blast furnaces abroad have adopted them, especially 68% of large blast furnaces with a hearth diameter of 12-15m have adopted them. According to statistics, in the past 10 years, 127 blast furnaces have been built with such high-quality bricks of more than 3,500t. Most blast furnaces use 270-800t each, and the parts used are from the tuyere, the furnace belly, the furnace waist to the furnace body lower middle etc.
3.2.4 Metal Heat Treatment Industry
There are various working conditions for metal heat treatment, and the working conditions are relatively harsh. Although silicon nitride ceramics are not necessarily suitable for various situations, under certain conditions, silicon nitride ceramics have good use effects. For example, gears are quenched into mandrels on equipment, used as fixtures for work pieces and hooks of heating elements in vacuum heat treatment.
4. Environmental protection industry
At present, in the environmental protection industry, most of the nozzles used in desulfurization and denitrification projects are made of silicon nitride combined with silicon carbide materials. Excellent chemical properties and long service life. At present, the amount of desulfurization and denitrification nozzles at home and abroad is increasing year by year.
5 Conclusion
Silicon nitride combined with silicon carbide material has high density, high strength, good thermal shock stability, high load softening point, good thermal conductivity, high resistance value, and excellent resistance to cryolite, aluminum fluoride, sodium fluoride and Calcium fluoride and other properties such as melting corrosion and oxidation resistance play an increasingly irreplaceable role in building sanitary ceramics, household ceramics, electric porcelain, non-ferrous smelting, steel rolling, iron making, heat treatment, environmental protection and other industries effect.
