Graphite is a super material of chemical industry, the chemical stability of the very prominent, acid and alkali resistance, corrosion resistance, in the chemical industry has a special position.
Natural graphite with bulk graphite and flake graphite is the best, the most widely used. I haven't found massive blocky Graphite Deposit, flake graphite and aphanitic graphite has a large deposit, and formed a large-scale mining base.
Natural graphite has many excellent properties, so it is widely used in various sectors of the national economy, especially in the metallurgical, mechanical, electrical, chemical industry has been widely used.
Graphite has outstanding resistance to high temperature and low temperature resistance properties, a small expansion coefficient, volume stability, so it can anti quench heat changes, the graphite resistance high temperature properties and general metal different when the temperature rises, it is not tend to soften, and its strength instead of increased.
Graphite is a good conductor of heat and electricity, similar to how the heat transfer performance and conductive performance and most metals, but also its characteristics, general metal when the temperature increases, thermal conductivity increased, and the thermal conductivity of graphite on the contrary, at elevated temperature, the thermal conductivity instead. At extremely high temperatures, the graphite tends to be insulated, and thus, in the case of high temperature, graphite Heat insulation performance is very reliable.
Graphite plasticity and lubrication has been obtained in industry, larger scales, friction coefficient is small, so graphite flake is the most slippery, lubrication best, dense crystalline graphite times, earthy graphite lubricant is poor.
Graphite or atomic reactor excellent moderator, the use of graphite has entered a new historical stage, in order to manufacture excellent retarding agent, graphite purification process was further developed, so graphite has become important materials in atomic energy industry.
Because of its special structure, graphite has special properties
1) high temperature resistant: Graphite melting point of 3850 + 50 DEG C, the boiling point of 42.5 DEG C, even the ultra high temperature arc ignition, weight loss is very small, coefficient of thermal expansion is also very small. Graphite strength increases with temperature, and the intensity of graphite is increased by one time at 2000.
2) the conductivity of graphite is one hundred times higher than that of general non metallic mineral. Thermal conductivity over steel, iron, lead and other metal materials. The thermal conductivity decreases with the increase of temperature, even in high temperature, graphite as insulator.
3) the lubrication performance of graphite is determined by the size of graphite flake, the bigger the scale, the smaller the friction coefficient, the better the lubrication performance.
4) chemical stability: graphite has good chemical stability at room temperature, acid, alkali and corrosion resistance to organic solvents.
5) plasticity: the toughness of the graphite is good, can be a very thin slice.
6) thermal shock resistance: graphite can withstand the temperature of the severe changes in the temperature of the temperature change and not cause damage, when the temperature is changed, the volume of graphite is not big, will not produce cracks.