Search results
Results From The WOW.Com Content Network
Aluminum enters the biosphere through water and food as soluble aluminum, Al 3+ or AlF 2+. It is then cycled through the food chain. [1] Aluminum has a low abundance in the biosphere but can be found in all organisms. [1] Humans, animals, and plants accumulate aluminum throughout their lives as it cycled throughout the food chain.
The only stable chalcogenides under normal conditions are aluminium sulfide (Al 2 S 3), selenide (Al 2 Se 3), and telluride (Al 2 Te 3). All three are prepared by direct reaction of their elements at about 1,000 °C (1,800 °F) and quickly hydrolyze completely in water to yield aluminium hydroxide and the respective hydrogen chalcogenide .
Some mixed oxide phases are also very useful, such as spinel (MgAl 2 O 4), Na-β-alumina (NaAl 11 O 17), and tricalcium aluminate (Ca 3 Al 2 O 6, an important mineral phase in Portland cement). [13] The only stable chalcogenides under normal conditions are aluminium sulfide (Al 2 S 3), selenide (Al 2 Se 3), and telluride (Al 2 Te 3).
3 C 2 H 5 Cl + 2 Al → (C 2 H 5) 3 Al 2 Cl 3. The reaction is carried out with aluminium in the form of turnings, shavings, granules, or powder. Oxygen and moisture must be rigorously excluded. The reaction can be initiated with a small amount of mercury or iodine. It also can be started by treating the aluminium with an alkylaluminium halide.
This category contains articles related to the chemical element aluminium (or aluminum) which is a non-ferrous metal See also the preceding Category:Magnesium and the succeeding Category:Silicon Wikimedia Commons has media related to Aluminium .
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer.Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al 2 O 3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. [1]
Its density is also lower than that of liquid aluminium (2 vs 2.3 g/cm 3), which allows natural separation of the product from the salt at the bottom of the cell. The cryolite ratio (NaF/AlF 3) in pure cryolite is 3, with a melting temperature of 1010 °C, and it forms a eutectic with 11% alumina at 960 °C. In industrial cells the cryolite ...
Al 2 Me 6 + 3 H 2 O → Al 2 O 3 + 6 CH 4. Under controlled conditions, the reaction can be stopped to give methylaluminoxane: AlMe 3 + H 2 O → 1/n [AlMeO] n + 2 CH 4. Alcoholysis and aminolysis reactions proceed comparably. For example, dimethylamine gives the dialuminium diamide dimer: [7] 2 AlMe 3 + 2 HNMe 2 → [AlMe 2 NMe 2] 2 + 2 CH 4