Monday, October 25, 2010

Aluminum - Facts Behind the Metal



A metallic element with symbol Al, aluminum is the 3rd most plentiful element of Earth's crust, behind that of oxygen and silicon. The metal has strong affinity towards oxygen and hence is not found in the elemental form but in combined states, such as silicates or oxides.

Bauxite is the main mineral ore of aluminum, which is abundantly available in tropical areas, such as - Africa, the West Indies, South America and Australia. Bauxite contains all types of impurities - mainly metals, such as iron - but comprises of 45 % to 60 % aluminum oxide, or alumina.

In its metallic form, aluminum metal does not occur naturally. It occurs only in combination with other minerals in the form of oxide or silicate compounds that constitute about 8% of earth's crust.

According to estimates, about 29 million tons of aluminum is required to meet the global demand every year. Of this total 29 million tons of total aluminum, around 22 million tons is new aluminum and 7 million tons is obtained by recycling the aluminum scrap. About 25% of the total amount of aluminum used across the world is recycled material.

Fact - 50% of the aluminum cans used today in the US are recycled.

According to estimates since 1972 around 16 million tons of aluminum cans have been recycled. These 785.6 billion aluminum cans if placed end-to-end could stretch to the moon more than 249 times.

Production of Aluminum

Production of aluminum is a two stage process that comprises of various intermediate steps. In the first stage, different mechanical and chemical stages are used to purify the bauxite and recover the alumina with the help of "Bayer Process".

Once the alumina - aluminum oxide trihydrate - is retrieved, it can be electrolytically reduced (transformed through electrochemical means) into metallic aluminum.

Some Facts -

  • Aluminum can be very strong, light (less than 1/3rd of the specific gravity of copper, brass or steel), ductile, and malleable.
  • The metal is an excellent conductor of heat and electricity.
  • Polished aluminum has the highest reflectivity of any material - even mirror glass.
  • The metal can be rolled, cast or extruded into an infinite array of shapes.
  • As a packaging material, aluminum as unique barrier characteristics. It resists corrosion and can be recycled again and again, without any loss of quality or properties.
  • The metal can be mixed with small, often minute, quantities of other materials, such as - copper, zinc, silicon, iron, magnesium, tin, titanium, lithium, chromium, tungsten, manganese, nickel, and others to create a variety of alloys with very different physical characteristics.
  • Aluminum metal is so widely used in todays' modern world that it is very difficult to imaging a world without it. The amazing, unique properties of this fundamental metal give it an extensive array of possible applications, including - transport, packaging, electrical application, medicine, and construction of homes and furniture.

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