Producao de aluminium

ALUMINIUM

Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances.

Aluminium is the third most abundant element (after oxygen and silicon), and the most abundant metal, in the Earth's crust. It makes up about 8% by weight of the Earth's solid surface. Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is found combined in over 270 different minerals. The chief ore of aluminium is bauxite.

Aluminium is remarkable for the metal's low density and for its ability to resist corrosion due to the phenomenon of passivation. Structural components made from aluminium and its alloys are vital to the aerospace industry and are important in other areas of transportation and structural materials. The most useful compounds of aluminium, at least on a weight basis, are the oxides and sulfates.

Despite its prevalence in the environment, aluminium salts are not known to be used by any form of life. In keeping with its pervasiveness, aluminium is well tolerated by plants and animals. Owing to their prevalence, potential beneficial (or otherwise) biological roles of aluminium compounds are of continuing interest.

Etymology

Two variants of the metal's name are in current use, aluminium and aluminum (besides the obsolete alumium). The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990 but, three years later, recognized aluminum as an acceptable variant. Hence their periodic table includes both. IUPAC prefers the use of aluminium in its internal publications, although nearly as many IUPAC publications use the spelling aluminum. Most countries use the spelling aluminium. In the United States, the spelling aluminum predominates. The Canadian Oxford Dictionary prefers