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When magnesium burns, it combines with oxygen (O 2) from the air to form magnesium oxide (MgO) according to the following equation: + () Magnesium oxide is an ionic compound containing Mg 2+ and O 2− ions whereas Mg (s) and O 2(g) are elements with no
The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) (obtained most often from bauxite , aluminium 's chief ore, through the Bayer process ) in molten cryolite and electrolyzing the molten salt bath, typically in a purpose-built cell.
Magnesium oxide (Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg 2+ ions and O 2− ions held together by ionic bonding .
Industrially, simple aluminium alkyls of the type Al 2 R 6 (R = Me, Et) are prepared in a two-step process beginning with the alkylation of aluminium powder: 2 Al + 3 CH 3 CH 2 Cl → (CH 3 CH 2) 3 Al 2 Cl 3. The reaction resembles the synthesis Grignard reagents. The product, (CH 3 CH 2) 3 Al 2 Cl 3, is called ethylaluminium sesquichloride ...
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 ]
In the following example, elemental aluminum reduces the oxide of another metal, in this common example iron oxide, because aluminum forms stronger and more stable bonds with oxygen than iron: Fe 2 O 3 + 2 Al → 2 Fe + Al 2 O 3. The products are aluminum oxide, elemental iron, [4] and a large amount of heat.
The Pidgeon process and the Bolzano process are similar. In both, magnesium oxide is the precursor to magnesium metal. The magnesium oxide is produced as a solid solution with calcium oxide by calcining the mineral dolomite, which is a solid solution of calcium and magnesium carbonates: CaCO 3 ·MgCO 3 → MgO·CaO + 2 CO 2
The process produces a quantity of fluoride waste: perfluorocarbons and hydrogen fluoride as gases, and sodium and aluminium fluorides and unused cryolite as particulates. This can be as small as 0.5 kg per tonne of aluminium in the best plants in 2007, up to 4 kg per tonne of aluminium in older designs in 1974.