AMORPHOUS GRAPHITE

Amorphous graphite is found as extremely small, crystal-like particles in beds of mesomorphic rocks like coal, slate and shale, and its carbon content depends on that of its parent material. When found in coal, it is the result of the thermal metamorphism of coal and is referred to as meta-anthracite. However, unlike coal, amorphous graphite is not used as fuel as it is difficult to ignite.

According to Riddle, amorphous graphite that is marketable today typically ranges in purity from 70 to 90 percent. “You can’t afford to upgrade it if you are to be cost effective,” he said.

Amorphous graphite uses

While amorphous graphite is one of the less popular types of graphite, it has its uses as well. Amorphous graphite is used in the refractories industry to manufacture crucibles, ladles, molds, nozzles and troughs that can withstand very high temperatures, particularly the casting of steel. Indeed, the electrodes used in many electrical metallurgical furnaces, including the electric arc furnaces used in steel processing, are manufactured from this type of graphite.

Furthermore, in the production of steel itself, graphite is used as a carbon raiser to strengthen steel. It’s also used in blast furnace linings for the production of iron because of its high thermal conductivity.

Aside from the refractories industry, amorphous graphite is used in brake linings, gaskets and clutch materials. Additionally, amorphous graphite is used in foundry facing mold wash, where it helps ease the separation of casted objects from molds. Finally, low-quality amorphous graphite, mostly from China, is used to make pencil lead.