Coke (fuel)
WEBRaw coke. Coke is a grey, hard, and porous coalbased fuel with a high carbon content. It is made by heating coal or oil in the absence of air. Coke is an important industrial product, used mainly in iron ore smelting, but also as a fuel in stoves and forges.. The unqualified term "coke" usually refers to the product derived from lowash and lowsulphur .