1. As refractories: graphite and its products have the properties of high temperature resistance and high strength. In metallurgical industry, it is mainly used to make graphite crucible. In steel making, graphite is commonly used as protective agent for steel ingot and lining of metallurgical furnace.
2. As conductive materials: in the electrical industry, it is used to manufacture electrodes, brushes, carbon rods, carbon tubes, positive electrodes of mercury positive current devices, graphite gaskets, telephone parts, coatings of TV picture tubes, etc.
3. As wear-resistant lubricating material: graphite is often used as lubricant in machinery industry. Lubricating oil can’t be used in high speed, high temperature and high pressure, but graphite wear-resistant material can work at 200 ~ 2000 鈩� and high sliding speed without lubricating oil. Many equipment conveying corrosive medium are widely made of graphite material, such as piston cup, sealing ring and bearing. They do not need to add lubricating oil during operation. Graphite emulsion is also a good lubricant for many metal processing (wire drawing, pipe drawing).
4. Graphite has good chemical stability. Graphite after special processing has the characteristics of corrosion resistance, good thermal conductivity and low permeability. It is widely used in making heat exchangers, reaction tanks, condensers, combustion towers, absorption towers, coolers, heaters, filters and pumps. Widely used in petrochemical, hydrometallurgy, acid-base production, synthetic fiber, paper and other industrial sectors, can save a lot of metal materials.
5. Used as casting, sand turning, die casting and high-temperature metallurgical materials: due to the small coefficient of thermal expansion of graphite and its ability to withstand rapid cooling and heating changes, graphite can be used as a mold for glassware. After using graphite, ferrous metal castings can be obtained with accurate size, smooth surface and high yield, which can be used without processing or slight processing, thus saving a lot of metal. In the production of cemented carbide and other powder metallurgy processes, graphite materials are usually used to make moulds and porcelain boats for sintering. Crystal growth crucible, regional refining vessel, support fixture and induction heater of monocrystalline silicon are all made of high purity graphite. In addition, graphite can also be used as graphite insulation board and base for vacuum smelting, high temperature resistance furnace tube, rod, plate, grid and other components.
6. Used in atomic energy industry and national defense industry: graphite has a good neutron retarder, which is used in atomic reactor. Uranium graphite reactor is a kind of atomic reactor which is widely used at present. The decelerating material used in power nuclear reactor should have high melting point, stability and corrosion resistance. Graphite can fully meet the above requirements. The purity of graphite used in atomic reactor is very high, and the impurity content should not exceed dozens of ppm. Especially the boron content should be less than 0.5ppm. In the national defense industry, graphite is also used to make solid fuel rocket nozzles, missile nose cones, aerospace equipment parts, heat insulation materials and anti radiation materials.
7. Graphite can also prevent the boiler from scaling. The tests of relevant units show that adding a certain amount of graphite powder into water (about 4 ~ 5g per ton of water) can prevent the boiler from scaling. In addition, graphite coating on metal chimney, roof, bridge and pipeline 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 and used in relevant industrial departments.
9. Electrode: how can graphite replace copper as electrode