What Is Graphite?
Graphite is a soft, crystalline form of carbon that occurs naturally in metamorphic rocks. It has a variety of industrial uses including high-temperature lubricants, brushes for electric motors and friction materials.
Molecular Structure
The structure of graphite is a layered one made up of sheets of carbon atoms that are linked together in a hexagonal array by strong chemical bonds, called covalent bonds. Each carbon atom has four valence electrons which participate in the formation of the bonds.
Van der Waals forces exist between the individual atomic sheets within each sheet of graphite and between the sheets themselves to hold them together. This allows the sheets to slide over each other with little resistance.
It is this greasy characteristic that makes graphite such an attractive dry lubricant. It also contributes to its durability and high strength.
Graphite can be formed from several sources. It is a natural mineral and occurs in veins and disseminations in metamorphic rock deposits.
Pure graphite is gray to black, opaque and has a metallic luster. It is a good conductor of electricity and a dry lubricant.
The refractory industry requires natural graphite to withstand the heat and chemicals used in metal production. Refractory graphite can be molded or extruded into desired shapes using a wide range of molding processes.
The value of refractory graphite can vary widely depending on flake size and impurities. The market for refractory graphite is small and primarily driven by large, high-volume buyers. However, demand for refractory graphite is increasing as demand for electric vehicles increases.
