Hall process

Hall process

The Hall process, also called the Hall-Héroult process, is the method by which most aluminum is produced commercially. Pure aluminum oxide, extracted from bauxite, is dissolved in molten cryolite at 970°C, and electrolyzed (see electrolysis) with a current of about 100 kA, through carbon electrodes. Molten aluminum is formed at the cathode and withdrawn from the bottom of the cell.


The process was devised independently in about 1886 by the American chemist Charles Martin Hall (1864–1914) and the French metallurgist Paul Louis Toussaint Héroult (1863–1914).