Carbothermic reactions involve the reduction of substances, often metal oxides (O2-), using carbon (C) as the reducing agent.
These chemical reactions are usually conducted at temperatures of several hundred degrees Celsius.
The ability of metals to participate in carbothermic reactions can be predicted from Ellingham diagrams.
The facility of these conversions is attributable to the entropy of reaction: two solids, the metal oxide (and flux) and carbon, are converted to a new solid (metal) and a gas (COx), the latter having high entropy.
Recently, development of the 'MagSonic' carbothermic magnesium process has restarted interest in its chemistry:[4] The reaction is readily reversible from its product vapors, and requires rapid cooling to prevent back-reaction.