Aluminium

Being in nature

   Natural aluminum consists almost entirely of a single stable isotope 27Al with traces of 26Al, a radioactive isotope with a half-life of 720 thousand years old, formed in an atmosphere of argon by bombarding nuclei with protons of cosmic rays.

   By prevalence in nature are # 1 in the metals industry and the 3rd place among the elements, second only to oxygen and silicon. The percentage of aluminum content in the earth's crust according to different investigators ranges from 7.45 to 8.14% by weight of the earth's crust.

   In the nature of aluminum due to the high chemical activity occurs almost exclusively in the form of compounds. Some of them:

         Bauxite - Al2O3 • H2O (doped with SiO2, Fe2O3, CaCO3)

         Nepheline - KNa3 [AlSiO4] 4

         Alunite - KAl (SO4) 2 • 2Al (OH) 3

         Alumina (a mixture of kaolin and sand SiO2, limestone CaCO3, magnesite MgCO3)

         Corundum - Al2O3

         Feldspar (orthoclase) - K2O × Al2O3 × 6SiO2

         Kaolinite - Al2O3 × 2SiO2 × 2H2O

         Alunite - (Na, K) 2SO4 × Al2 (SO4) 3 × 4Al (OH) 3

         Beryl - 3VeO • Al2O3 • 6SiO2

   Nevertheless, in some specific reducing conditions, formation of native aluminum.

   In natural waters, aluminum contained in the form of low-toxic chemical compounds, such as aluminum fluoride. Kind of cation or anion depends primarily on the acidity of the water environment. Concentrations of aluminum in surface waters ranging from 0,001 Russia up to 10 mg / liter.