What is Graphite?
Graphite is one of the allotropicforms of Carbon, which is the 6th element of the periodic table ofthe elements. The other natural allotropic form of Carbon is Diamond, the mostimportant artificial forms are Graphenes, Fullerenes and Nanotubes.
The mineral Graphite was named by Abraham Gottlob Werner in 1789 from the Greek word “grafein” meaning “to write”. Usually it isformed by a process of metamorphism out of initially organic carbonic material,seldom it is formed by hydrothermal or other geological processes.
Types of Graphite
Natural graphite can be dividedin three forms:
- Crystalline flake graphite occurs as disseminated, flat, plate-like particles. Flake graphite is always disseminated in a host rock and needs therefore enrichment (flotation) for commercial use. Flake graphite can be found in several deposits around the globe. It has a very wide range of industrial applications which are described further down.
- Amorphous graphite consists of small graphite particles build out of micro or even nano-sized crystallites. Amorphous graphite is usually associated with coal deposits and can be found around the globe. The typical application for amorphous graphite is metallurgy.
- Vein graphite is hydrothermal in origin and occurs in fractures of rocks with vein width from 0 to some dozen cm. The graphite is very pure with an in situ carbon content up to >99%. It is, like the flake graphite, a highly crystalline form of carbon. The vein type of graphite is rather seldom, the only commercial mining operations are presently in Sri Lanka, the output is low. Applications are e.g. carbon brushes.