How is aluminum produced?
Aluminium is too reactive to exist in its natural state. On the other hand, it is found in over 270 different minerals, including bauxite. This is first converted into aluminum oxide (alumina) through the Bayer process. By dissolving it with caustic soda, it is possible to produce large amounts of alumina.
Afterwards, the dissolution of the alumina and the decomposition of the mixture by electrolysis, commonly known as the Hall-Héroult process, transform the alumina into aluminum and significantly reduce the production costs.
What is aluminium used for?
Aluminium is a soft metal, which is light and highly resistant, yet very malleable. Known for its high conductivity, it is also an excellent insulator when oxidized or anodized. It is very often used for wing cable pathways and conductors; however, an alloy made with other elements is necessary where greater strength is required.
Through qualities such as lightness, good electrical and thermal conductivity, corrosion resistance and recycling, aluminum is used in an ever-increasing number of applications. Initially reserved for luxury jewelry, it is now used both in the manufacture of kitchen utensils and in the field of aviation.
What is the density of aluminium?
With a density three times less than steel or copper, aluminum is one of the lightest metals commercially available. Test results of the stiffness to unit weight ratio clearly demonstrate that this is a structural material capable of withstanding significant loads, as well as providing significant fuel savings to the transport industry.
What is the strength and corrosion resistance of aluminum?
Aluminium in its pure form does not provide very high resistance but a mixture with small amounts of manganese, copper or magnesium can produce alloys with highly-valued properties for the packaging, construction, paint and pyrotechnics fields, among others.
Aluminium is well adapted to cold environments. Unlike steel, which becomes brittle in cold weather, aluminum has the advantage of keeping its tensile strength while maintaining its hardness.
Furthermore, oxidized steel parts have rust spots, which weaken these regions, while oxidized aluminum parts enhance its protective properties. It is even possible to chemically increase the thickness of this oxide layer by anodization, thereby forming aluminum oxide, an insulating layer that prevents spark formation. Alumina, a very good conductor, combined with aluminum oxide, an excellent insulator, makes aluminum a material sought after by most industries.
On a final note, aluminum is fairly resistant to most acids but less so to alkalis.