The industrial manufacture of is based on the Hall-Heroult process developed in 1886. In this process is dissolved in a cryolite (Na₃AlF₆) melt and electrolyzed at 940 to 980°C with direct current. Molten metallic aluminum is deposited at the carbon electrode (cladding of the bottom) and taken off as a liquid. Oxygen is formed at the anode, also of carbon (presintered or Soederberg-electrode), with which it reacts forming carbon dioxide and carbon monoxide.

The electrolyte essentially consists of sodium hexafluoroaluminate (synthetic cryolite) with added aluminum fluoride and lithium fluoride. The latter is formed in situ from lithium carbonate. These additives make up 2 to 5% of the bath content and result in a reduced melt temperature, an increase in the melt conductivity, an increase in the yield based on electricity consumption and reduced fluorine emission. Over 40% of the aluminum producers in North America already use these additives.

Aluminum oxide is added in an amount of 7 to 12%, dependent upon the bath composition. The eutectic mixture, sodium aluminum hexafluoride/aluminum oxide with 10.5% aluminum oxide, melts at 960°C. The yield with respect to current consumed is 85 to 95%, the cell voltage is 4.5 to 5%, the anode consumption is ca. 0.5 kg/kg aluminum, the power rating of a plant - consisting of many (100 to 200) individual cells connected in series - is in the range 50 to 300 kA.

Aluminum production is very energy intensive, ca. 18 kWh is on average consumed per kg aluminum (in modern plants 14 kwhlkg).

It has been possible in recent years to reduce strongly the fluorine emission and thereby the fluorine consumption e.g. by dry adsorption and dry chemisorption of the hydrogen fluoride-containing gases from the electrolysis furnace with aluminum oxide.
 
Liquid aluminum (99.5 to 99.9% pure) is produced in the electrolysis furnace by three layer melt electrolysis with the help of fluorine-containing fluxes or by fractional crystallization.

Production processes other than the melt electrolysis of aluminum oxide, such as the energetically more favorable and environmentally more favorable electrolysis of aluminum chloride, have only minor industrial importance.