Also known as "pen lead" or "black lead", it is mainly composed of carbon (C).Graphite produced in nature is formed by reduction at high temperature.Widely distributed is sedimentary metamorphic graphite, which is formed from sedimentary rocks rich in organic matter or carbon through regional metamorphism.For example, coal seams or carbonaceous sedimentary rocks can generate graphite through metamorphism.Magmatic rock and limestone contact, limestone decomposition of CO2 through reduction can also form graphite.Graphite is rarely pure, often containing a large amount of mechanical mixture, such as quartz, mica, salt, iron oxide, magnesium oxide, calcium oxide, phosphorus pentoxide, etc.Sometimes there is CO2, CO, H2, CH4, N2 and other gases and water and asphalt.The graphite crystal is a layered lattice of hexagonal rings of carbon atoms linked together to form a large planar network, parallel to each other and superimposed.The more common graphite crystals belong to the hexagonal system.Complete crystals are rare, usually platy, scaly.Amorphous graphite is often in bulk and powder form.Where the crystal diameter of natural graphite is less than 1 micron, in the general microscope also difficult to see its crystal dense graphite aggregate, known as microcrystalline graphite (also known as amorphous graphite or earthy graphite).

Graphite color from iron ash to steel ash, stripe black, with significant optical inhomogeneity, hardness inhomogeneity, as well as opaque, with metallic luster, etc.Hardness 1 ~ 2, specific gravity 2.09 ~ 2.23, secondary graphite specific gravity 1.84 ~ 1.98.The specific gravity depends on the number of bubbles.Flakes can bend and become greasy, contaminating paper and fingers.Graphite has strong heat transfer (higher than copper and aluminum), high conductivity, can withstand high temperatures above 3000℃, melting point 3800℃, boiling point 4250℃, plasticity, chemical stability, insoluble in acid base.

1, manufacturing electric smelting furnace, electrolytic pool, arc lamp and arc welding electrode and generator, motor brush, resistor and telephone carbon bar.

2, manufacturing various metallurgical crucible.

3. Because it absorbs a large number of neutrons, graphite can be used as a speed reducer in atomic stacks, but it must be highly pure crystalline graphite.

4, used as sand mold surface coating, rust coating, machine lubricant, bearing lubricant.

5, all kinds of refractory and refractory insulation mixture.

6, make anti-corrosion paint.

7, the manufacture of pencil lead, as a black coloring material.

8, through special chemical treatment, can be made into a flexible sealing material.