Bauxite and cryolite are added to a large steel trough which is lined with carbon to form a cathode. Aluminium is reduced at the cathode and sinks to the bottom of the cell. Oxygen is evolved because it is lower in the anion reactivity series than fluorine. Many aluminium smelters are near to cheap sources of electricity such as hydro-electric power stations. Environmental Damage open-cast bauxite mines can devastate the countryside alkaline waste is produced from the treatment of ore with sodium hydroxide a small amount of fluoride ions are oxidised at the anode to produce fluorine.
Fluorine pollutes agricultural land.
Uses of Aluminium Aluminium is a very useful metal even though it is quite high in the reactivity series. Its tough oxide coating resists corrosion. Uses for aluminium include window and door frames drinks cans, baking foil and milk bottle tops saucepans, because it is a good conductor of heat electric cables, because it is a good conductor of electricity. Aluminium and its alloys are used in aircraft construction because they have strength and low density. Duralumin Not all exam boards require this.