2. Used as conductive material: used in the electrical industry to make electrodes, brushes, carbon rods, carbon tubes, positive electrodes of mercury rectifiers, graphite washers, telephone parts and coatings for TV picture tubes.
3. As a wear-resistant lubricating material: Graphite is often used as a lubricant in the mechanical industry. Lubricating oil cannot be used at high speed, high temperature and high pressure, while graphite wear-resistant materials can work at a very high sliding speed at a temperature of 200~2000℃ without lubricating oil. Many equipments for transporting corrosive media widely use graphite materials to make piston cups, sealing rings and bearings, and do not need to add lubricating oil during operation. Graphite emulsion is also a good lubricant for many metal processing (wire drawing and tube drawing).
4. Graphite has good chemical stability. Specially treated graphite has the characteristics of corrosion resistance, good thermal conductivity and low permeability, so it is widely used to make heat exchangers, reaction tanks, condensers, combustion towers, absorption towers, coolers, heaters, filters and pumps. Widely used in petrochemical industry, hydrometallurgy, acid-base production, synthetic fiber, paper making and other industrial sectors, which can save a lot of metal materials.
5. Casting, sand casting, molding and high-temperature metallurgical materials: graphite has a small thermal expansion coefficient and can be used as a mold for glassware. After graphite is used in ferrous metal castings, the size is accurate, the yield is high, and it can be used without processing or with a little processing, saving a lot of metal. Powder metallurgy processes, such as the production of cemented carbide, usually use graphite materials to make molds and porcelain boats for sintering. The crystal growth crucible, regional refining container, supporting fixture and induction heater of monocrystalline silicon are all processed by high purity graphite. In addition, graphite can also be used as graphite insulation board and base for vacuum melting, high temperature resistance furnace tubes, rods, plates, grid sheds and other parts.
6. Used in atomic energy industry and national defense industry: graphite has a good neutron moderator used in atomic reactors, and uranium-graphite reactor is a widely used atomic reactor. The deceleration material used as power in atomic energy reactor should have high melting point, stability and corrosion resistance, and graphite can fully meet the above requirements. As an atomic reactor, the purity of graphite is very high, and the impurity content cannot exceed tens of PPM. In particular, the boron content should be less than 0.5PPM. In the national defense industry, graphite is also used to manufacture nozzles of solid fuel rockets, nose cones of missiles, parts of space navigation equipment, heat insulation materials and radiation protection materials.
7. Graphite can also prevent the boiler from scaling. Relevant unit tests show that adding a certain amount of graphite powder (about 4 ~ 5g per ton of water) can prevent the boiler from scaling. In addition, graphite coatings on metal chimneys, roofs, bridges and pipelines can prevent corrosion and rust.
8. Graphite can be used as pencil lead, pigment and polishing agent. After special processing, graphite can be made into various special materials for use by relevant industrial departments.
In addition, graphite is also a polishing agent and antirust agent for glass and paper making in light industry, and is an indispensable raw material for manufacturing pencils, inks, black paints, inks, synthetic diamonds and diamonds. It is a good energy-saving and environment-friendly material, and has been used as a car battery in the United States. With the development of modern science and technology and industry, the application field of graphite is still expanding, and it has become an important raw material for new composite materials in high-tech fields and plays an important role in the national economy.