What is Coke (fuel)?
'''Coke''' is a [[fuel]] used mainly in [[blast furnace]]s to reduce [[iron oxide]] to produce [[iron]]. It contains [[carbon]], and is similar to [[coal]]. It is made from coal by cooking out things that are not carbon. Coke is a product of destructive distillation of coal. This is done in an airless [[furnace]] or oven ([[kiln]]) at temperatures as high as {{convert|2000|°C|°F|-2}} but usually around {{convert|1000|-|1100|°C|°F|-2}}.<ref>{{cite web|url=http://www.worldcoal.org/coal/uses-of-coal/coal-steel/|title=Coal and Steel|publisher=World Coal Association|access-date=2016-03-08|archive-date=2012-03-14|archive-url=https://web.archive.org/web/20120314103442/http://www.worldcoal.org/coal/uses-of-coal/coal-steel/|url-status=dead}}</ref> This baking drives off [[volatiles|volatile]] parts of the coal, such as [[water]], [[gas]], and [[tar]]. Coke is an almost pure form of carbon. The [[calorific value]] (heat energy produced when a fuel is burnt) of coke is about 56,000 kilojoules/kilogram. [[File:Coke Ovens Abercwmboi.jpg|right|thumb|Coke oven at [[smokeless fuel]] plant, [[Abercwmboi]], South [[Wales]], 1976]] Coke is used as a fuel and as a [[reducing agent]] in [[smelting]] [[iron ore]] in a [[blast furnace]]. The [[carbon monoxide]] produced by its combustion reduces iron oxide ([[hematite]]) to the iron product. Although coke is more expensive than coal, it can be used in households as a clean fuel, relatively free of smoke and impurities. At the present day its use in domestic heating has been less than oil or gas, but in the 20th century it was often used in kitchen [[stoves]]. == References == {{reflist}} {{-}} {{tech-stub}} [[Category:Fuel]]