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Aluminium – important information
Aluminium is the most common chemical element after oxygen and silicon. It is found everywhere in oxide form: in the ground, air and water. As much as 8% of the earth’s crust is aluminium. Aluminium is industrially extracted from bauxite, which has an aluminium content of approximately 25%. Bauxite deposits are found on both sides of the equator. The world’s bauxite deposits are limitless and increase with the weathering of rock.
It is light
Aluminium’s specific weight is 2.7 kg/dm3, i.e. less than one third of the specific weight of steel. A steel beam with equal strength properties is about twice as heavy as an aluminium beam. The light weight and strength of aluminium result in significant savings in the transport industry, for example. The use of aluminium in cars, trains, ships, planes and other vehicles saves money in operating costs and enables greater effective loads.
It is resistant to corrosion
Aluminium is very resistant to corrosion because it reacts with the oxygen in the air and forms a hard and firm oxide layer which prevents further oxidization. This property gives aluminium structures a long life and reduces the need for maintenance. Corrosion-resistance can be further improved with anodization which also gives aluminium an attractive surface.
It is easy to shape
Modern extrusion technology and low tool costs give designers great freedom to tailor profiles to suit each specific use. It is easy to include various features in the profiles to facilitate assembly and make them more functional. Various surface treatment options ensure that profiles are suitable for various uses depending on their surface and colour.
It conducts heat
Aluminium’s capacity to conduct heat is used mainly in the electronics industry. Aluminium conducts heat about three times better than iron.
It conducts electricity
Aluminium conducts electricity very well and this conductivity can be further improved with special alloys especially developed for this purpose. An aluminium wire is half the weight of a copper wire with the same conductivity.
It is environmentally friendly
It is true that extracting aluminium from bauxite uses a large amount of electricity, about 16,000 kWh/tonne. New methods are, however, being developed and energy consumption has been successfully reduced to 10,000 kWh/tonne in pilot plants. In addition, in the production of primary aluminium, the energy used is "stored" in the aluminium. Melting secondary aluminium only requires 5% of the energy that was needed to melt the primary aluminium. Aluminium is also a valuable recycling metal which can easily be sorted from other metals and used over and over again. Three-quarters of all aluminium waste is recycled, which is a significant amount in the national economy.
