Coke is made by destructive distillation of a blend of selected Bituminous coals (called Coking coal or Metallurgical coal) in special high temperature ovens in the absence of oxygen until a greater part of the volatile matter is driven off. The resulting product, COKE, consists principally of Carbon with sizes ranging from basketballs (foundry coke) to fine powder (coke breeze).

Coke is primarily used to smelt iron ore and other bearing materials in blast furnaces, acting both as a source of heat and as a chemical reducing agent to produce pig iron or hot metal.