Aluminium is produced in modern times through the Hall-Héroult Process, whereby a molten aluminium oxide electrolyte is electrolysed between graphite electrodes. A simplified diagram of the cell is shown below.
Although the production of aluminium is expensive, it is worth the cost. Aluminium is light, so it is useful in the manufacture of aircrafts and cars. Aluminium is often used as window frames, particularly at the sea. It protects itself from corrosion by producing a layer of aluminium oxide on its surface, which is very tough and therefore difficult to remove.