What is Aluminium?

Aluminium is the most common metallic element on earth, making up about 8% of the earth's crust, concentrated in the outer 16 km. Only oxygen and silicon are more abundant. Evolution of life and human civilisation has developed in an aluminium rich environment. It is the most widely used non-ferrous metal today. Aluminium never occurs in its metallic form in nature. It occurs in various forms in most rocks and soils and is also present in gemstones like topaz and garnet. It can be found in vegetation and in all of the earth's water. Aluminium is also present in all clays, so it has been a constituent of cooking vessels since earliest civilisations.

The naturally occurring forms of aluminium are usually stable and do not interact with the biological processes of living organisms. Under acidic conditions aluminium may be released from rocks and soils in a soluble form which is more available for uptake by plants and animals. However, uptake of this soluble form is limited by the presence of natural agents such silicates and fluorides.

Chemistry of aluminium

• is a light silvery-white metallic element
  
• has the chemical symbol Al
  
• has an atomic number of 13
  
• has a valency of three
  
• is resistant to corrosion - it is very reactive but forms a tough layer of oxide when exposed to air, preventing further corrosion
  
• is strong when alloyed even with small amounts of silicon and iron
  
• is ductile and lightly malleable
  
• is an excellent conductor of heat and electricity
  

The benefits of aluminium beverage cans

The history of aluminium