One of the main uses of graphite products is the production of refractory materials, including refractory bricks, crucibles, continuous casting powder, mold cores, molds, detergents, and high-temperature resistant materials. In recent years, two important changes in the refractory industry are the wide application of magnesia-carbon bricks in the lining of steelmaking furnaces and the application of aluminum-carbon bricks in continuous casting. Graphite refractories are closely related to the steelmaking industry, which consumes about 100% of refractory materials worldwide. Steelmaking
Other impurity substances can be used as carburizes in the steelmaking industry. Carburizing uses a wide range of carbonaceous materials, including artificial graphite, petroleum coke, metallurgical coke, and natural graphite. Graphite for steelmaking recarburizer is still one of the main uses of earthy graphite in the world.
as conductive material
Graphite products are widely used in the electrical industry as electrodes, brushes, carbon rods, carbon tubes, positive electrodes of mercury rectifiers, graphite gaskets, telephone parts, coatings for TV picture tubes, etc. Among them, graphite electrodes are the most widely used. Graphite electrodes are used for various alloy steels and iron alloys. At this time, a strong current passes through the electrodes into the melting zone of the electric furnace to generate an arc and convert electrical energy into heat energy. To achieve the purpose of smelting or reaction. In addition, when electrolyzing metal magnesium, aluminum, and sodium, graphite electrodes are also used for the anode of the electrolytic cell. The resistance furnace for producing corundum also uses graphite electrodes as the conductive material of the furnace head. Graphite used in the electrical industry has high requirements on particle size and grade. For example, alkaline storage batteries and some special electric carbon products require graphite particle size to be controlled within the mesh range, above grade, and below harmful impurities (mainly metallic iron). The particle size requirements of graphite used in TV picture tubes are as follows. As a wear-resistant and lubricating material, graphite is often used as a lubricant in the machinery industry. Lubricating oil often cannot be used under high-speed, high-temperature, and high-pressure conditions, while graphite wear-resistant materials can work at low temperatures and extremely high sliding speeds (/) without lubricating oil. Many types of equipment conveying corrosive media widely use graphite materials to make piston rings, sealing rings, and bearings. They operate without adding lubricant. Graphite milk is also a good lubricant for many metal processing (wire drawing, tube drawing).
corrosion resistant material
Graphite products have good chemical stability. Specially processed graphite has the characteristics of corrosion resistance, good thermal conductivity, and low permeability, and is widely used in the production of heat exchangers, reaction tanks, condensers, combustion towers, absorption towers, coolers, heaters, filters, pumps, etc. Equipment. These devices are used in petrochemical, hydrometallurgy, acid and alkali production, synthetic fiber, papermaking, and other industrial sectors, which can save a lot of metal materials. 0 It is used for casting, casting, molding, and high-temperature metallurgy materials. Due to the small expansion coefficient of graphite, it can withstand changes in rapid cooling and rapid heating and can be used as a casting mold for glassware. After using graphite, ferrous metal castings have accurate dimensions and smooth surfaces. High efficiency, can be used without processing or with a little processing, saving a lot of metal. In the production of cemented carbide and other powder metallurgy processes, graphite materials are usually used to manufacture pressure-resistant sintered boats. Crystal growth crucibles, regional refining vessels, brackets, fixtures, and induction heaters for monocrystalline silicon are all made of high-purity graphite. In addition, graphite can also be used as a graphite insulation board and substrate for vacuum metallurgy, high-temperature resistant furnace tubes, rods, plates, grids, and other components.
For the atomic energy industry and the defense industry
Graphite has good neutron deceleration properties and was first used as a moderator in atomic reactors. The uranium-graphite reactor is currently the most widely used atomic reactor. As a deceleration material in a power atomic energy reactor, it should have the characteristics of a high melting point, good stability, and corrosion resistance. Graphite can fully meet the above requirements. The purity of graphite used in atomic reactors is very high, and the impurity content should not exceed tens (parts per million), especially since the boron content should be less than 100%. Graphite is also used in the defense industry to make nozzles for solid-fuel rockets, nose cones for missiles, parts for aerospace equipment, thermal insulation, and radiation-resistant materials.
Anti-scale and anti-rust materials
Graphite prevents the fouling of boilers. Tests by relevant units have shown that adding a certain amount of graphite powder (approximately per ton of water) to water can prevent scaling on the boiler surface. Additionally, graphite coatings on metal chimneys, roofs, bridges, and pipes protect against corrosion and rust.
New Uses for Graphite
With the continuous development of science and technology, people have also developed many new uses for graphite. Flexible graphite products. Flexible graphite, also known as expanded graphite, is a new type of graphite product developed in the 1990s. The United States successfully developed flexible graphite sealing materials, which solved the leakage problem of atomic energy valves, and then Germany, Japan, and France also began to develop and produce them. In addition to the characteristics of natural graphite, this product also has special flexibility and elasticity. Therefore, it is an ideal sealing material. Widely used in petrochemical, atomic energy, and other industrial fields. The demand in the international market is increasing year by year.
High-purity products are used in high-purity metal smelting, the electronics industry, the nuclear industry, and mold manufacturing; ordinary products are used in masonry materials for aluminum electrolytic cells, powder metallurgy sintering furnaces, ferroalloy furnaces, and other submerged arc furnaces.