Emery

In 1891, American Choral cutter mixed clay and coke and put it in an iron bowl, attempting to convert carbon into diamond by electric arc. But as a result, a sparkling six square crystal was found near the electrode, which is different from the cubic eight face of natural diamond. Acheson thinks this may be a new compound produced by reaction of alumina in carbon and clay. Since one of the alumina minerals in nature is called corundum, he connects two English words with carbon and corundum as the name of the new compound, which Chinese scholars translate into "Emery". Later it was known that the compound was formed by the reaction of silicon dioxide and carbon at high temperature in clay.
The unit cell is a face centered cubic structure. Each cell contains 4 C atoms and 4 Si atoms. It is similar to the diamond structure.
Silicon carbide hardness is second only to diamond, boron carbide and cubic boron nitride, ranking fourth in inorganic materials. At present, high density silicon carbide has been prepared by hot pressing sintering. It has high strength and good antioxidant properties. It is not deformed at high temperature. It can be used as a turbine blade on high temperature gas turbine. It can also be used as a wear-resistant sealing material. It can also be used as a nozzle of a rocket tail nozzle and light bullet proof articles.
Adamanta, SiC, also known as silicon carbide. Pure is a colorless crystal. The density is 3.06 to 3.20. The hardness is about 9.5 degrees. In general, it is a colorless powdery particle. After grinding, it can be used as abrasive powder, which can wipe the paper and make the friction surface of grinding wheel and whetstone. It is heated by sand and appropriate carbon in an electric furnace.
Natural emery, also known as garnet, is a silicate mineral. Abrasive materials made by hydraulic separation, mechanical processing, screening and grading. Production has a long history. In ancient China, there were examples of the use of diamond grinding crystal glass and all kinds of jade. In 1840s, it was also exported to Dongyang. It is divided into three categories: coarse mesh, middle order and detail. The coarse mesh is black and red, the middle order is light red, the detail is red white, all kinds of visual size are uniform, the shape of the particles is uniform, the angle is called angle crystal, with sharp edge and high grinding force. For stone industry grinding marble and other soft materials. Glass industrial grinding glass burrs, TV kinescope, optical instruments, lenses, prisms, glass for watches and clocks. Metal industry sandblasting, derusting, grinding. The printing industry is used for rubbing offset plates, as well as for light industrial processing plastic, leather, sandpaper and so on.
The grinding force of the natural emery is slightly lower than that of the white corundum in the electric furnace. However, it has a strong wayward nature and has the characteristics of the shell shaped section. Its advantages are the high smoothness of the grinding parts and the less and shallow sand marks. The fine and uniform grinding surface can improve the quality of products, which is the unique feature of this product. The natural diamond has short grinding time, high efficiency and low price, which can make up for the short life span.