How is aluminium made?
Today we think of aluminium as a familiar and common metal. Yet unlike metals such as iron, bronze and copper, it has only been possible to make aluminium since the early to midnineteenth century. It has only been used for drink cans in Australia for about 20 years. Bauxite is the raw material used to produce aluminium and the first stage is to remove alumina from the bauxite by dissolving it in liquid caustic. The residues which are insoluble in the caustic are used as mud bricks or as aggregate for road foundations. The final stage in the production of aluminium is the smelting of alumina into metal in furnaces. Smelting is the process of removing oxygen from the alumina to produce pure aluminium. The pure molten aluminium is subsequently poured into a mould to make it into an ingot shape and then ingots can be rolled or “squashed” between large rollers to produce products such as aluminium foil or sheet.
