Abstract

Graphite is the soft, gray-black form of crystalline carbon; the other forms of crystalline carbon are diamond and fullerenes. Graphite occurs naturally as crystalline flake, mined as flat hexagonal flakes in usually weathered metamorphic rock, as amorphous in former coal beds subjected to additional heat and pressure, and as lump or high-crystalline graphite occurring in hydrothermal veins in its host rock in Sri Lanka. Natural graphite is not mined in the United States. It is usually mined by open-pit and beneficiated (crystalline flake) by flotation. Its principal sources are China and Brazil, then Canada, Mexico, and Madagascar.

Flake graphite can also be recovered from a steelmaking waste called kish. Competition within China sets the world price. Natural graphite is used principally in graphite-containing refractories for steelmaking that are thermally conductive and resist high temperatures, in automotive brake linings, and in batteries, pencils, lubricants, and crucibles. It may come to be used in fuel cells to power nonpolluting vehicles.