Search results
Results From The WOW.Com Content Network
Although a molten aluminium salt could be used instead, aluminium oxide has a melting point of 2072 °C (3762°F) [4] so electrolysing it is impractical. In the Hall–Héroult process, alumina, Al 2 O 3 , is dissolved in molten synthetic cryolite , Na 3 AlF 6 , to lower its melting point for easier electrolysis. [ 1 ]
An aluminium smelter consists of a large number of cells (pots) in which the electrolysis takes place. A typical smelter contains anywhere from 300 to 720 pots, each of which produces about a ton of aluminium a day, though the largest proposed smelters are up to five times that capacity.
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 ...
Efficient aluminium smelting requires low resistance on the part of the anode. Low resistance results in greater control over the electrolysis cell's voltage and reduces the energy loss associated with resistive heating. [9] However, anodes with low electrical resistance also exhibit increased thermal conductivity.
An electrolytic process is the use of electrolysis industrially to refine metals or compounds at a high purity and low cost. Some examples are the Hall-Héroult process [1] used for aluminium, or the production of hydrogen from water.
Roasting heats the ore in the presence of oxygen from air, oxidizing the ore and liberating the sulfur as sulfur dioxide gas. Smelting most prominently takes place in a blast furnace to produce pig iron, which is converted into steel. Plants for the electrolytic reduction of aluminium are referred to as aluminium smelters.
Primary aluminium smelting is the process of extracting aluminium from aluminium oxide (also known as alumina). The process takes place in electrolytic cells that are known as pots. The pots are made up of steel shells with two linings, an outer insulating or refractory lining and an inner carbon lining that acts as the cathode of the ...
Bust of Heroult in Thury-Harcourt. Paul (Louis-Toussaint) Héroult (10 April 1863 – 9 May 1914) was a French scientist. He was one of the inventors of the Hall-Héroult process for smelting aluminium, and developed the first successful commercial electric arc furnace. [1]