china high-quality graphite electrodes
China high-quality graphite electrodes talk about taking you to uncover the mystery of graphite
There are various minerals on the beautiful earth. Some minerals have been mined and used by people. Graphite is one of them. The graphite you know is probably a black pencil lead with moderate hardness. Oh, yes, high school physics also told you that there is graphite in batteries. In fact, as early as 3,000 years ago, the Shang Dynasty had written characters with graphite. China has a long history of discovering and using graphite, and “Shui Jing Zhu” contains “the graphite mountain on the side of Luoshui.”
The mountains and rocks are so black that they can be sparsely written, so graphite is the name of the mountain. Graphite has become an indispensable substance in our daily life due to its own special properties. What kind of graphite is around you? Do you want to know how graphite is formed? Let us approach graphite together and lift the mystery of graphite!
The name of graphite comes from the Greek “‘means “to write” and was named by the German chemist and mineralogist A. G. in 1789. It is a mineral produced in the form of a simple substance composed of carbon elements
China has a long history of discovering and using graphite. Discovered from archaeological excavations of oracle bones, jade pieces, and pottery pieces, writings written in graphite were used in the Shang Dynasty more than 3,000 years ago, and it lasted until the end of the Eastern Han Dynasty (220). Graphite was used as a book ink by Songyan Ink. replace. During the Daoguang period of the Qing Dynasty (1821~1850), farmers in Chenzhou, Hunan Province exploited graphite as fuel, which was called “oil carbon”.
At the beginning of the 20th century, the technology of using graphite to make batteries and pencils was introduced to China. At that time, graphite called electric coal and “pen lead” began to be used in modern industry, which promoted the development of China’s graphite mining industry.
Graphite belongs to the hexagonal crystal system in the crystal structure. The monomer is in the form of flakes or plates, often in the form of scaly or massive aggregates. Its hardness is very low, with a Mohs hardness level of 1, which is a soft substance. Because of its special structure, graphite has its special properties.
1. High temperature resistance
The melting point of graphite is 50°C, and the boiling point is, even if burned by ultra-high temperature arc, the weight
The loss is very small, and the coefficient of thermal expansion is also very small. The strength of graphite increases with the increase of temperature, and the strength of graphite is doubled at 2 000°C.
2. Electrical and thermal conductivity
The electrical conductivity of graphite is 100 times higher than that of general non-metallic minerals, and the thermal conductivity is higher than that of metal materials such as steel, iron, and lead. Its thermal conductivity decreases with increasing temperature, and even becomes an insulator at extremely high temperatures. Graphite can conduct electricity because each carbon atom in graphite only forms 3 covalent bonds with other carbon atoms, and each carbon atom still retains 1 free electron to transfer charge.
The lubricating performance of graphite depends on the size of the graphite flakes. The larger the flakes, the smaller the friction coefficient and the better the lubricating performance.
4. Chemical stability
Graphite has good chemical stability at room temperature, and is resistant to acid, alkali and organic solvent corrosion.
Graphite has good toughness and can be crushed into very thin flakes.
6. Thermal shock resistance
Graphite can withstand drastic changes in temperature without being damaged when used at room temperature. When the temperature changes suddenly, the volume of graphite does not change much, and cracks will not occur. This article chooses: china high-quality graphite electrodes.