Aluminium Rock File

You probably best know aluminium as the can holding your soft drink, or the foil covering food in your fridge. In fact, aluminium is the second-most used metal (after iron) as it can be alloyed with almost any other metal to create materials with a whole range of useful properties, all very strong yet also very lightweight and resistant to rusting. Some of these alloys have special names; for example, you might have heard of Zincalume or Duralumin. Aluminium is also in many precious and beautiful gemstones such as turquoise, rubies, sapphires, emeralds, topaz, jade and aquamarines.

Aluminium is by far the most plentiful metal in Earth's crust, however, whereas copper, gold, lead and zinc were used by humans thousands of years ago, aluminium has only been used for a little over 100 years because humans did not know until then how to purify it!

Building and construction

As aluminium is strong, light, easily shaped and resistant to rust, it is used in cladding, doors, window frames, awnings and bridge rails.

Transport

For the above reasons, aluminium parts are found in cars, trucks, buses, aircraft, ships, rail and trams.

Appliances

Also for the above reasons: fridges, washing machines, lawn mowers etc.

Heating and Ventilation

As aluminium is a good conductor of heat, it is used in heating and cooling systems.

Packaging

As aluminium can be rolled into very thin sheets and is non-toxic, it is used for kitchen foil, packaging foil, cans and containers.

Electrical and Communications

Aluminium's ability to conduct electricity means it is used for power transmission including towers, electrical conduit, machinery and equipment, telephone cables and capacitors.

Other

Utensils (cutlery, pans), industrial machinery, chemical industry, production of steel, anti-perspirants, furniture, reflectors in telescopes, making high octane petrol, road signs, antacids, and jewellery.

Never found in its pure form, aluminium is locked together with other elements. For example, the ore from which we most commonly obtain aluminium is called bauxite (a mixture of aluminium, oxygen and hydrogen).

Australia is the world's largest producer and exporter of aluminium, mining 40% of the world's bauxite. Our major mining areas are Weipa in North Queensland (Matthew Flinders first noticed the 'reddish cliffs' there in 1802), Gove in the Northern Territory and the Darling Range in Western Australia.

Aluminium-bearing rock is blasted in open-pit mines, scooped up by front-end loaders and crushed. The aluminium oxide (called alumina) is separated from the waste rock by dissolving in caustic soda. The aluminium is then separated from the oxygen using a process called 'electrolysis', which uses large amounts of electricity. An electric current is passed through a solution containing the alumina. The oxygen combines with the carbon anode and forms carbon dioxide gas. The aluminium settles at the bottom of the pot and is siphoned off. Impurities are removed, alloying elements can be added, and the molten aluminium is cast into various shapes and sizes, depending on the end use required.