The blast furnace is a vertical shaft furnace that produces liquid metal by the reaction of the flow of air introduced under pressure into the bottom of the furnace with a mixture of metallic ore, coke, and flux fed onto the top. Blast furnaces are used to produce pig iron from iron ore for subsequent processing into steel, and they are also employed in processing lead, copper, and other metals. Rapid combustion is maintained by the current of air under pressure.
