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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 ...
Decoupage or découpage ( / ˌdeɪkuːˈpɑːʒ /; [ 1] French: [dekupaʒ]) is the art of decorating an object by gluing colored paper cutouts onto it in combination with special paint effects, gold leaf, and other decorative elements. Commonly, an object like a small box or an item of furniture is covered by cutouts from magazines or from ...
In physical chemistry and engineering, passivation is coating a material so that it becomes "passive", that is, less readily affected or corroded by the environment. . Passivation involves creation of an outer layer of shield material that is applied as a microcoating, created by chemical reaction with the base material, or allowed to build by spontaneous oxidation
Black for aluminum. Boil a solution of 20 g ammonium molybdate and 5 g of sodium thiosulfate in a liter of water, immerse the objects, rinse, dry, wax or lacquer after the development of color. [31] Lustre colours. Use a solution of 280 g of sodium thiosulphate, 25 g of cupric acetate and 30 g of citric acid. It can be used on copper and its ...
Electrophoretic deposition ( EPD ), is a term for a broad range of industrial processes which includes electrocoating, cathodic electrodeposition, anodic electrodeposition, and electrophoretic coating, or electrophoretic painting. A characteristic feature of this process is that colloidal particles suspended in a liquid medium migrate under the ...
Anodizing. These carabiners have an anodized aluminium surface that has been dyed; they are made in many colours. Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. The process is called anodizing because the part to be treated forms the anode electrode of an ...
A solution of these ions can have the correct pH to preferentially dissolve silicon oxide rather than the aluminum oxides and iron oxides. [14] Silcrete has been suggested to form in zones in relatively dry "precipitating zones" of laterites. [15] To the contrary, in the wetter parts of laterites subject to leaching ferricretes have been ...
Bayer process. 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]