Aluminium is a silvery-white metal, the 13 elements in the periodic table. One surprising fact about aluminium is that it's the most widespread metal on Earth, making up more than 8% of the Earth's core mass. It's also the third most common chemical element on our planet after oxygen and silicon.
But regardless of how common aluminium may be, it may have remained hidden forever if it hadn't been for electricity. The discovery of aluminium was made possible when scientists were able to use electricity to break down chemical compounds into their elements. In the 19 century, the Danish physicist Christian Oersted used electrolysis to obtain aluminium. Electrolysis or electrolytic reduction is the process that is used to produce aluminium today as well.
Bauxite is used today as the primary raw material in aluminium production. Bauxite is a clay mineral comprising various modifications of aluminium hydroxide mixed with iron, silicon, titanium, sulphur, gallium, chromium, vanadium oxides, as well as sulphuric calcium, iron and magnesium carbonates. On average, 4-5 tonnes of bauxite are needed to produce 1 tonne of aluminium.
In the first stage of aluminium production, bauxite is processed into alumina, or aluminium oxide Al2O3. Alumina looks like white powder and it is then processed into aluminium at aluminium smelters using electrolytic reduction.
Aluminium production requires huge amounts of electricity, about 15 MWh per tonne of output. That's approximately as much as a 100-apartment block consumes in a month. So the best site for an aluminium smelter is next to a powerful, preferably renewable, energy source. Hydroelectric power plants are the best option as they are the most powerful 'green' energy sources available today.