Search results
Results from the WOW.Com Content Network
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.
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 ...
Aluminium recycling is the process in which secondary commercial aluminium is created from scrap or other forms of end-of-life or otherwise unusable aluminium. [1] It involves re-melting the metal, which is cheaper and more energy-efficient than the production of virgin aluminium by electrolysis of alumina (Al 2 O 3 ) refined from raw bauxite ...
Cryolite (Na 3 Al F 6, sodium hexafluoroaluminate) is an uncommon mineral identified with the once-large deposit at Ivittuut on the west coast of Greenland, mined commercially until 1987. [ 8 ] It is used in the reduction ("smelting") of aluminium, in pest control, and as a dye.
In 1891 after Cowles began to advertise "pure aluminum" they were sued by the Pittsburgh Reduction Company. The judge announced his decision in January 1893, finding them to be infringing the patent of Hall and having gained knowledge of his process by hiring away a chemist named Hobbs who was the foreman in Pittsburgh.
The Wöhler process was one of the first routes for producing aluminium metal. It involves the reduction of anhydrous aluminium chloride with potassium , produced powdered aluminium: [ 1 ] AlCl 3 + 3 K → Al + 3 KCl
Julia Brainerd Hall (November 11, 1859 – September 4, 1926) [1] was the sister of American scientist Charles Martin Hall. She supported him in his discovery of the Hall process for extracting aluminium from its ore. [2] She was also a still-life painter who exhibited at the Edgar Adams Gallery in Cleveland. [3]
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 (1,832 °F) and quickly hydrolyse completely in water to yield aluminium hydroxide and the respective hydrogen chalcogenide .