Iron is smelted from iron ore in large reactors called blast furnaces. A blast furnace is a tall vertical structure which is fed with coke, iron ore and limestone. When hot air is blown in the blast furnace, the coke will burn and reduce the oxygen off the ore, producing bare iron and carbon dioxide. The limestone will bind off any remaining bedrock. The iron melts in the hot temperature and is tapped off in liquid phase at the bottom. It is then worked into steel. The limestone and bedrock form a compound called slag. It can be used for making bricks, concrete or road topping. Earlier methods include Bloomery.
Aluminum is smelted in electric ovens called electric arc furnaces. The aluminum ore is poured on the bottom of the furnace and electric current is led through the ore. The temperature rises so high that the oxygen separates, leaving metallic aluminum.
Copper is poured on naked flame which burns off sulfur and other impurities, leaving raw copper. Electrolysis uses electric current to separate the copper in big pools, which contain water solution called electrolyte

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