We explain what aluminum is, how it is classified and the physical properties it presents. Also, its characteristics, uses and recycling.
What is aluminum?
Aluminum is a metallic element represented on the periodic table with the symbol ‘Al’ and the third most common element in our planet’s crust: 8% of the Earth’s crust contains aluminum in various compounds.
Aluminium was first isolated in 1825 by the Danish physicist HC Orsted, and today it is the most widely used metal by humanity, along with iron.
This element is also present, in most rock formations and in the body itself of living beings. However, it is not possible to find it in a pure state in nature, but rather as part of numerous silicates and minerals.
Is about one of the most useful and most industrially used metals by humanity, given its properties of lightness, malleability and long life, as well as resistance to corrosion. It is used in a huge variety of alloys to manufacture numerous utensils and containers, as well as parts of various machinery.
See also: Steel
Atomic properties of aluminum
Aluminum (Al) It is located between magnesium (Mg) and silicon (Si), in group III A of the Periodic Tableidentified with an atomic number of 13, and among the ‘p’ block metals. Its atomic mass is 26.98 u and its oxidation state is 3+.
Appearance of aluminum
The aluminum In a state of purity it is a shiny metal, light, more or less gray-white in color. Its appearance may vary depending on the numerous alloys to which it can be subjected.
Physical properties of aluminum
The aluminum It is a non-ferromagnetic and extremely light metal. with respect to many metals, which makes it ideal for numerous industrial applications, such as the manufacturing of containers (cans) or panels. Its melting point is very low (660 °C) and it is soft and malleable. It is a good electrical and thermal conductor.
Obtaining aluminum
The most common process for obtaining aluminum is extract it from bauxite, a mineral abundant on Earth. This process involves a significant amount of electrical energy, which means it is an expensive process; but the result is a useful material, with a long useful life (corrosion resistant) and a very low recycling cost. All this contributes to it having a stable price and being an economical element.
Aluminum applications
Aluminum is an enormously versatile and central element in numerous human industries, and its applications are countless.
From the Manufacturing of metal parts and machinery componentseither in its purest state or in alloys (especially to contribute to its hardening), to the production of mirrors, containers of various kinds, aluminum foil, tetrabriks, telescopes and as a component of welding.
First appearances of aluminum
Aluminum has been present throughout human history, in the form of salts useful for medicine and dry cleaning. But it did not appear as a pure element until 1825, when the Danish physicist HC Orsted managed to obtain some impure samples by electrolysisTwo years later, Friedrich Wöhler obtained the first pure samples.
Initially It was considered a precious metal and exhibited alongside the crown jewels of France in 1855, but the widespread use of it and lower costs led it to become a common metal.
Aluminum reactivity
Aluminum is very reactive, although it is resistant to corrosion through a layer of alumina (Al2O3) that forms around it in the presence of oxygen and isolates the rest of the metal from corrosion. It can be easily diluted in hydrochloric acid (HCl(aq)) or sodium hydroxide (NaOH)as well as in numerous acids and bases.
Aluminum recycling
The aluminum can be perfectly recycled without altering its physical propertieswhich represents a considerable economic advantage over other metals.
This process also requires very little energy (barely 5% of the original production process). This remelted aluminium is known as ‘secondary aluminium’.
Main aluminum alloys
Since aluminum is a soft metal with little resistance to mechanical tractionits use is varied but not recommended as a structural material.
In this sense, it is usually alloyed with other metals to contribute to its hardening, such as magnesium, manganese, copper, zinc and silicon, sometimes even titanium and chromium.
Aluminum alloys are identified by series:
- 1000 series. Almost pure. About 99% aluminum.
- 2000 Series. Alloys with copper.
- 3000 Series. Alloys with manganese.
- 4000 Series. Alloys with silicon.
- 5000 Series. Alloys with magnesium.
- 6000 Series. Alloys with magnesium and silicon.
- 7000 Series. Zinc alloys.
- 8000 Series. Alloys with other metallic and non-metallic elements.
Aluminum toxicity
Contrary to what was considered for decades, aluminum it is not harmless to humans. Its degree of toxicity is low, since dietary aluminum is absorbed in small quantities through the intestine. However, inhalation of aluminum dust or saturation of the element in food can lead to liver and kidney damage, or symptoms of neurotoxicity.
The abundant presence of aluminum has also been linked to the incidence of Alzheimer’s disease.
Follow with: Gold