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Pure cryolite has a melting point of 1009 ± 1 °C (1848°F). With a small percentage of alumina dissolved in it, its melting point drops to about 1000 °C (1832°F). Besides having a relatively low melting point, cryolite is used as an electrolyte because, among other things, it also dissolves alumina well, conducts electricity, dissociates electrolytically at higher voltage than alumina, and ...
Swelling results in early and non-uniform deterioration of cathode blocks. Anode: Carbon anodes have a specific situation in aluminium smelting and depending on the type of anode, aluminium smelting is divided in two different technologies; “Soderberg” and “prebaked” anodes. Anodes are also made of petroleum coke, mixed with coal-tar ...
Gases are generated from reactions of water with compounds such as un-oxidised aluminium, un-oxidised sodium metal, aluminium carbide and aluminium nitride. Typical gases from the reaction of SPL with water are: Hydrogen from aluminium and water – 2Al + 3H 2 0 → 3H 2 + Al 2 O 3; Hydrogen from sodium metal and water – 2Na + 2H 2 0 → H 2 ...
Pulse electrolysis is an alternate electrolysis method that utilises a pulsed direct current to initiate non-spontaneous chemical reactions. [1] [2] [3] Also known as pulsed direct current (PDC) electrolysis, the increased number of variables that it introduces to the electrolysis method can change the application of the current to the electrodes and the resulting outcome.
The electrolysis can be done on a molten metal oxide (smelt electrolysis) which is used for example to produce aluminium from aluminium oxide via the Hall-Hérault process. Electrolysis can be used as a final refining stage in pyrometallurgical metal production (electrorefining) and it is also used for reduction of a metal from an aqueous metal ...
In electrochemistry, exchange current density is a parameter used in the Tafel equation, Butler–Volmer equation and other electrochemical kinetics expressions. The Tafel equation describes the dependence of current for an electrolytic process to overpotential .
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]
Anodization – a process that converts the surface of a metal into a durable corrosion-resistant oxide layer; Conductive polymers – organic polymers that conduct electricity; Water electrolysis – a process that uses an electric current to split water molecules into hydrogen and oxygen gases