Very pure copper is required for telephone cables. The tutorial gives help with the new formulas and equations. Extraction of Iron Heating coal without air drives off most impurities to give nearly pure carbon called coke. Coke is the fuel for the blast furnace. Fe 2 O 3 coke and limestone are added at the top of the blast furnace.
Air is forced in at the bottom to react with the coke.
Heating limestone produces calcium oxide and carbon dioxide. The CO 2 reacts with more coke to produce carbon monoxide. It is a more effective reducing agent than carbon in the blast furnace. The molten iron runs down and is tapped off at the bottom. The iron produced by the blast furnace is called cast iron .