Application of graphite powder
Graphite powder has a hardness of 1 to 2, a specific gravity of 1.9 to 2.3, and a boiling point of 4250 ° C. It is one of the minerals resistant to high temperatures, but it is relatively stable at room temperature. Graphite powder is an ideal raw material for refractory materials and conductive materials. Let's get to know graphite powder now!
First, the definition of graphite powder.
Graphite powder is soft and dark gray; it has a greasy feel and can contaminate paper. The hardness is 1 to 2, and the hardness can be increased to 3 to 5 with the increase of impurities in the vertical direction. The specific gravity is 1.9 to 2.3. Under the condition of being isolated from oxygen, its melting point is above 3000 ℃, and it is one of the most temperature-resistant minerals. Chemical properties of graphite powder are relatively stable at room temperature, insoluble in water, dilute acid, dilute alkali and organic solvents; react with oxygen at different high temperatures to form carbon dioxide or carbon monoxide; only fluorine in halogen can directly react with elemental carbon; under heating, Graphite powder is more natural to be oxidized by acids; at high temperatures, it can also react with many metals to form metal carbides, which can smelt ores at high temperatures.
Second, the use of graphite powder.
Used in the atomic energy industry and national defense industry: graphite has a good neutron moderator used in nuclear reactors. Uranium and graphite reactors are one of the most widely used atomic reactors. As a deceleration material in a nuclear power reactor for power, it should have a high melting point, stability, and corrosion resistance. Graphite can completely meet the above requirements. The purity of graphite used in atomic reactors is very high, and the impurity content should not exceed tens of PPM. In particular, boron content should be less than 0.5 PPM. In the defense industry, graphite is also used to make nozzles for solid-fuel rockets, nose cones for missiles, parts for space navigation equipment, thermal insulation materials, and anti-ray materials.
Graphite has excellent chemical stability. Specially processed graphite has the characteristics of corrosion resistance, good thermal conductivity, and low permeability. It is widely used in the manufacture of heat exchangers, reaction tanks, condensers, combustion towers, absorption towers, coolers, heaters, and filters. Pump equipment. Widely used in petrochemical, wet metallurgy, acid and alkali production, synthetic fiber, papermaking, and other industrial sectors, can save a lot of metal materials.
Graphite can be used as casting, sand turning, compression molding, and high-temperature metallurgy materials: Because graphite has a small thermal expansion coefficient and can withstand rapid and rapid changes, it can be used as a mold for glassware. After graphite is used, ferrous metal can obtain accurate casting dimensions and a smooth surface High rate, can be used without processing or a little processing, thus saving a lot of metal. Production of powder metallurgy processes such as cemented carbide, graphite materials is usually used to make stampers and porcelain boats for sintering. Crystal growth crucibles for single crystal silicon, regional refining vessels, holder fixtures, induction heaters, etc. are all processed with high-purity graphite. In addition, graphite can also be used for vacuum smelting of graphite heat insulation plates and bases, high-temperature resistance furnace tubes, rods, plates, grids, and other components.
Graphite can also prevent boiler scaling. Related tests have shown that adding a certain amount of graphite powder (approximately 4 to 5 grams per ton of water) can prevent scaling on the boiler surface. In addition, graphite can be applied to metal chimneys, roofs, bridges, and pipes to avoid corrosion and rust.
Graphite can be used as pencil lead, pigment, and polishing agent. After the special processing of graphite, various unique materials can be made for the relevant industrial sectors.
In addition, graphite is also a polishing agent and rust inhibitor for glass and paper in the light industry. It is an indispensable raw material for the manufacture of pencils, inks, black paints, inks, and artificial diamonds and diamonds. It is a perfect energy-saving and environmental-friendly material, and it 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. It has become an essential raw material for new composite materials in the high-tech area and plays a vital role in the national economy.