1. Refractory materials include refractory bricks, crucibles, continuous casting powder, mold cores, mold detergents, and high temperature resistant materials
Magnesia-carbon bricks. Magnesia-carbon refractory materials were successfully developed by the United States in the mid-1960s. Magnesia-carbon bricks have been widely used in steelmaking around the world and have become a traditional use of graphite. Aluminum carbon bricks and aluminum carbon refractory materials are mainly used for continuous casting, protective covers for flat steel billet self-positioning pipelines, underwater nozzles, and oil well blasting barrels, etc.
Shaped and refractory crucibles and related products made of graphite, such as crucibles, retorts, plugs, and nozzles, have high fire resistance, low thermal expansion, and are stable when subjected to metal infiltration and erosion during the metal smelting process. They have good thermal shock stability and excellent thermal conductivity at high temperatures. Therefore, graphite crucibles and related products are widely used in the process of directly melting metal.
2. Steelmaking
Graphite and other impurity materials can be used as carburizers in the steelmaking industry. The range of carbonaceous materials used for carburizing is very wide, including artificial graphite, petroleum coke, metallurgical coke, and natural graphite. Graphite used as carburizing agent in steelmaking is still one of the main uses of earthy graphite worldwide.
3. Use as conductive material
Graphite is widely used in the electrical industry as electrodes, brushes, carbon rods, carbon tubes, positive electrodes of mercury rectifiers, graphite gaskets, telephone parts, coatings for television picture tubes, etc. Among them, graphite electrodes are widely used. When smelting various alloy steels and ferroalloys, graphite electrodes are widely used. Graphite used in the electrical industry has very high requirements on particle size and quality.
4. Use as wear-resistant and lubricating materials
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 temperatures between 1200°C and 2000°C and at very high sliding speeds (loom/s) without lubricating oil. Many equipment transporting corrosive media widely use graphite materials to make piston rings, sealing rings, and bearings. When they are running, there is no need to add lubricating oil. Graphite emulsion is also a good lubricant for many metal processing operations (wire drawing, tube drawing).
5. Use as corrosion-resistant materials
Graphite has 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, and other equipment. This equipment is used in the petrochemical industry, hydrometallurgy, acid and alkali production, synthetic fiber, paper making, and other industrial sectors, which can save a lot of metal materials.
6. Used in the atomic energy industry and the defense industry
Graphite has good neutron deceleration properties and was used as a moderator in atomic reactors earlier. The "uranium-graphite" reactor is a type of atomic reactor that is currently widely used. As the deceleration material in the atomic energy reactor used for power, it should have high melting point, stability, and corrosion resistance. Graphite can fully meet the above requirements.
7. Used as anti-scale and anti-rust materials
Graphite prevents boiler scaling. Tests have shown that adding a certain amount of graphite powder to water can prevent boiler surface scaling. In addition, graphite coating on metal chimneys, roofs, bridges, and pipes can prevent corrosion and rust.
8. New uses of graphite
(1) Flexible graphite products.
Flexible graphite, also known as expanded graphite, is a new graphite product developed in the 1970s. In 1971, the United States successfully researched flexible graphite sealing materials, which solved the leakage problem of atomic energy valves. Subsequently, Germany, Japan, and France also began development and production. 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, and the international market demand is growing year by year.
(2) Make semi-metallic friction materials.
Since the 1970s, semi-metallic friction materials have been widely used in clutches and automatic linings. Semi-metal friction material is made of graphite, metal powder, steel fiber, and clay powder bonded with synthetic resin. These automatic liners are primarily used in high-speed equipment such as brakes and clutch plates on aircraft, trucks, and off-road vehicles.