Aluminiumi

Aluminiumi is a chemical element with the symbol Al and atomic number 13. It is a metal in the boron group. Aluminium is a relatively soft, ductile, lightweight, nonmagnectic and silvery-white metal. It is the third most abundant element in the Earth's crust, making up about 8% of the crust by mass, although it is less common in the Earth's mantle. The top aluminium producing countries are China, India, Russia, Canada and the United Arab Emirates.

Aluminium is highly reactive and readily forms a thin layer of aluminium oxide when exposed to air. This oxide layer protects the bulk metal from further oxidation. It is this oxide layer that gives aluminium its resistance to corrosion. Aluminium is a good conductor of heat and electricity, and it is also a good reflector of light.

Aluminium is the most widely used metal after iron. Its low density, high strength, and corrosion resistance make it ideal for a wide range of applications, including aircraft, automobiles, construction, packaging, and consumer goods. Aluminium is also used in the production of alloys, which are mixtures of two or more elements. These alloys can have significantly different properties than the pure metal, making them even more versatile.

Aluminium is extracted from bauxite ore, which is a reddish-brown rock that contains aluminium hydroxide. The bauxite is first crushed and ground, and then treated with a solution of sodium hydroxide. This process dissolves the aluminium hydroxide, leaving behind the impurities. The aluminium hydroxide is then filtered and heated to remove water, producing aluminium oxide. Finally, the aluminium oxide is dissolved in molten cryolite and electrolysed to produce pure aluminium. This process is known as the Hall-Heroult process.