Graphite Powder
Size
1≥60%, etc
Package
25kg small bags into ton bags or ton bags
Features
High temperature resistance, conductivity and thermal conductivity, etc.
Application
As refractory material, conductive material and wear-resistant lubricating material, etc.
Graphite powder is a widely used industrial material, which is obtained from high-purity graphite after crushing, grinding, and screening. The classification of graphite powder is mainly based on the particle size, ranging from 50 mesh to 30000 mesh. The larger the mesh, the finer the particle size, and the higher the price.
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Hexagonal boron nitride, also known as white graphite. Hexagonal boron nitride is the simplest boron nitrogen polymer. Similar to the hexagonal carbon network in graphite, nitrogen and boron in hexagonal boron nitride also form hexagonal network layers, overlapping each other to form crystals. The crystal is similar to graphite, with diamagnetism and high anisotropy, and the crystal parameters are quite similar. Boron nitride is used in refractories.
Refractory materials refer to a class of inorganic non-metallic materials with a refractoriness of not less than 1580 °C. Any material whose physical and chemical properties allow it to be used in a high temperature environment can be called a refractory material. Refractory materials are used in glass, steel, ceramics, non-ferrous metals, cement, petrochemical, machinery, boilers, light industry, electric power, military and other national economic fields. It is an important basic material to ensure the above-mentioned industrial production operation and technological development, and plays an irreplaceable important role in the development of high-temperature industrial production.
Boron nitride refractory material belongs to the refractory compound material in the classification of composite materials, belongs to special refractory material, and is a new type of inorganic non-metallic material developed on the basis of traditional ceramics and general refractory materials. The melting point can reach above 2000°C. It has good electrical insulation, thermal conductivity, chemical corrosion resistance and lubricity, and also has strong neutron absorption capacity. In the air below 1000°C, various physical and chemical properties basically remain unchanged. Nitrogen or argon is still stable at 3000°C.
Hexagonal boron nitride’s advantages as a refractory material
(1) As a new inorganic non-metallic material, compared with traditional inorganic non-metallic materials, boron nitride refractories not only have the advantages of traditional inorganic non-metallic materials, but also have high strength, electrical properties, optical properties and biological functions.
(2) For the addition of boron nitride and very fine aluminum powder to aluminum carbon and magnesium carbon refractories, it is found that a part of boron nitride reacts with carbon and aluminum to form oxynitrides and carbides during carbon buried firing. The addition of boron nitride reduces the weight loss efficiency of the oxidation reaction of aluminum carbon and magnesia carbon bricks, and improves the oxidation resistance of the bricks. When the addition amount is appropriate, the corrosion resistance to bricks is also significantly improved.
Mechanism of hexagonal boron nitride
Hexagonal boron nitride coating is mainly used for special refractory materials. It can improve the performance of refractory materials by adhering to the surface of refractory materials or penetrating the refractory working layer. The particle size of boron nitride is between 20 microns and 50 microns. The mass content is between 30% and 85%, and the mass content of the boron oxide coating is between 2% and 5%. The boron nitride coating with large particle size boron nitride powder and boron oxide as the main body is in the low temperature stage, and the boron oxide melts to form a high-viscosity melt, which enhances the adhesion of the boron nitride coating. At the same time, due to the existence of a liquid phase, Boron oxide also plays a combustion-supporting role. At high temperature, boron oxide reacts to form boron nitride. The reaction produced by boron nitride has high activity and can promote the sintering of boron nitride coating. Due to the presence of boron nitride powder with large particle size, the final coating will not be sintered and dense, and the coating will have a small firing shrinkage rate to avoid separation from the substrate.
The future development of white graphite will continue to be needed, the demand will gradually rise, and the production capacity will continue to grow.
