Impure form of carbon , obtained as a residue when material containing carbon is partially burned or heated with limited access to air.
natural gas as a raw material, charcoal is still used to make black gunpowder and in case-hardening metals. Activated charcoal is a finely powdered or highly porous form whose surface area is hundreds or thousands of square meters per gram. It has many uses as an adsorbent (see adsorption ), including for poison treatment, and as a catalyst or catalyst carrier.