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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. The Hall–Héroult process ...
Ziegler process. In organic chemistry, the Ziegler process (also called the Ziegler-Alfol synthesis) is a method for producing fatty alcohols from ethylene using an organoaluminium compound. The reaction produces linear primary alcohols with an even numbered carbon chain. The process uses an aluminum compound to oligomerize ethylene and allow ...
Aluminium smelting. Straumsvik aluminum smelter, operated by Rio Tinto Alcan in Iceland. Aluminium smelting is the process of extracting aluminium from its oxide, alumina, generally by the Hall-Héroult process. Alumina is extracted from the ore bauxite by means of the Bayer process at an alumina refinery.
Aluminium oxide is an amphoteric substance, meaning it can react with both acids and bases, such as hydrofluoric acid and sodium hydroxide, acting as an acid with a base and a base with an acid, neutralising the other and producing a salt. Al 2 O 3 + 6 HF → 2 AlF 3 + 3 H 2 O Al 2 O 3 + 2 NaOH + 3 H 2 O → 2 NaAl(OH) 4 (sodium aluminate)
The chemical formula for TEOS is given by Si(OC 2 H 5) 4, or Si(OR) 4, where the alkyl group R = C 2 H 5. Alkoxides are ideal chemical precursors for sol–gel synthesis because they react readily with water. The reaction is called hydrolysis, because a hydroxyl ion becomes attached to the silicon atom as follows: Si(OR) 4 + H 2 O → HO−Si ...
A high-purity (≥99.9998%) aluminium bar that has been etched to reveal the component crystallites. Chemical milling or industrial etching is the subtractive manufacturing process of using baths of temperature-regulated etching chemicals to remove material to create an object with the desired shape. [1][2] Other names for chemical etching ...
The structure of the methoxide ion. In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as RO−, where R is the organyl substituent. Alkoxides are strong bases [citation needed] and, when R is not bulky, good nucleophiles and good ...
Atomic layer deposition (ALD) is a thin-film deposition technique based on the sequential use of a gas-phase chemical process; it is a subclass of chemical vapour deposition. The majority of ALD reactions use two chemicals called precursors (also called "reactants"). These precursors react with the surface of a material one at a time in a ...