Aluminium
What it is
Aluminum is a silver-white metal of low density which was not discovered before 1808. It has low weight and great strength, high electric and thermal conductivity and is particularly corrosion resistant to water and chemicals. Aluminum is safe for human health and occurs in nature in combination with various elements. Its melting point is 660.4°C, and its boiling point 2,467°C. Its density of 2.7 g/cm³ clearly demonstrates its light-metal character.
Where it is found
With a share of 7.57 percent by weight, aluminum is the most frequent metal in the crust of the earth. In nature, aluminum is never found in pure form, but always bound to oxygen. It is omnipresent in feldspar and mica or in their weathering products. Bauxite probably is the best-known aluminum mineral; it is obtained exclusively by open-pit mining. Bauxite is an earthy sedimentary rock with great variations in composition. The main components are alumina (40 – 60 %), iron oxide (5 – 30 %) and silica (1 – 15 %). The iron oxide gives bauxite the reddish color it mostly has. Bauxite deposits worthy of being mined are found in Brazil, China, Australia, New Guinea, in Western Africa and in India.
What it is used for
In view of its low density, high conductivity, corrosion resistance and easy workability, aluminum can be used for many purposes. The biggest consumer of aluminum is the transport sector where it is used for light-weight cars, commercial vehicles, aircrafts etc. But aluminum is also used in the construction industry (external facing, roof and wall systems), and in mechanical engineering as well as in the packaging industry. As it has a low weight, is impermeable and easy to deform into a variety of shapes, aluminum packaging is made in many different types for many different products
How it is traded
Aluminum is offered as billets for pressing or rolling, or as pigs, depending on customers’ requirements. It is also found in the market as semi-finished product, as alloy or in liquid form. 25-ton contracts are traded at the metal exchange.