, according to the difference of atomic arrangement in the structure,can be devided to three kinds of carbon allotropes, namely, diamond, graphite and amorphous carbon, their physical properties, chemical properties and usage are different.

1, diamond: is the hardest natural substance known, its crystal structure is basically is face-centered cubic lattice, each carbon atom is surrounded by four carbon atoms around are connected by covalent bond, high intensity, mohs hardness is 10, so often used for cutting, grinding and cutting materials. When diamond contains trace impurities, have the performance of the semiconductor, can do the high temperature rectifier or solid state microwave devices, etc.

Natural diamond and precious stones (diamond). Diamond is divided into Ⅰ, Ⅱ and six-party type 3 kinds. Ⅰ type of impurity content is higher, the nitrogen content at 0.0025% ~ 0.0025%, most of the natural diamond belong to this type. Ⅱ type is extremely pure diamond, crystallization is complete, the nitrogen content of less than 0.001%, good thermal conductivity, with semiconductor performance. Natural diamond in 1% ~ 2% belong to this type. Using special artificial methods (such as super high pressure high temperature) can be of non-diamond carbon into diamond structure, namely synthetic diamond.

2, , carbon atom with four coordination polyhedron of network layer, network layer to molecular bonds between connection, form a hexagonal. Graphite is special inorganic nonmetallic materials, the performance of both metal and plastic and a host of other features, in metallurgy, chemical, electricity and electronics, machinery, textile and atomic energy industries for a wide range of applications.

The purpose of the graphite closely associated with its nature.

(1) high temperature resistance, thermal stability is good, also do not melt under 3600 ℃, thus used as a crucible (see image) in metallurgical industry, the furnace refractory material.

(2) good thermal conductivity and electrical conductivity (4 times higher than stainless steel), conductive coefficient varies with temperature increase and decrease. Used to make electrode, brush, carbon rod, heat exchanger, cooler, etc.

Can (3) good chemical stability, acid, alkali and organic media, common to make alkali industry, petrochemical industry, textile, paper and other industrial heat exchanger, reaction tank, burning tower, absorption tower, cooler and pump, heater, etc.

(4) the lubrication performance similar to molybdenum disulfide, wear resistance, friction coefficient is less than 0.1, can be in 200 ~ 2000 ℃ and 100 m/s speed, used to make the seal and bearing, need not add lubricant.

(5) good plasticity, can extend into pervious to light, breathable slice.

6. Have good neutron slowing, deceleration material used for atomic reactor. In addition, also used for nozzles of solid rocket parts, aerospace equipment, insulation and prevent radiation material. Is the chief drawback of graphite oxidation at high temperature, that need to be used in a protective atmosphere.

Graphite ore crystal and implicit crystal. Crystalline graphite ore has dense and scales crystallization two kinds, the former grain is greater than 0.1 mm, carbon content in 60% ~ 65%, even as high as 80% ~ 90%, but poor plasticity, can flotation. Crystal flake graphite ore grade is low (3% ~ 5% or 10% ~ 25%), but the performance is good. Aphanitic graphite is also called the earthy graphite, carbon content up to more than 90%, but poor performance. For earthy graphite from the half of the world.

The Soviet union is the largest country in the graphite ore reserves and production. Graphite also relatively rich resources in China, mostly scales and implicit SPAR ink. Due to graphite ore grade is not high, need to the separation and purification, the commonly used flotation process (graphite as the hydrophobic) and gravity separation method (graphite relative density is small, 1.9 ~ 2.3), and can make the carbon content of 90% in the finished product, some products also need to use chemical purification, the carbon content or high temperature purification to 97% ~ 97% to 99%. [1]

3, amorphous carbon, carbon atoms are arranged disorderly, or forming of the grain size is too small. Coal, natural gas, oil or other organic matter at about 1000 ℃ carbonization of amorphous carbon is a porous material, its surface area is very large. Products such as carbon black and activated carbon.

Hi-tech Material Co., Ltd is a carbon group company which is the worldwide leading manufacturer of graphite material, graphite felt and carbon carbon composite.


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