What material is the anode used in
the Hall–Héroult process for the extraction of aluminum made from?
In this question, we are asked
about the material used for the anode within the Hall–Héroult cell. In the Hall–Héroult process,
electrolysis to extract aluminum occurs inside an aluminum smelting plant. Electrolysis is the chemical
process where electricity is passed through an electrolyte, causing it to decompose
into its constituent elements.
The extraction of aluminum happens
at sites all across the world, with aluminum smelting plants producing around
200,000 tons of aluminum each year. Aluminum is extracted from the
compound alumina after it is mixed into an electrolyte solution with cryolite. This lowers the required melting
temperature of alumina to make the process less costly.
The anodes and cathodes used in
these cells are made of carbon. Both electrodes are made from an
electrically conductive form of carbon known as graphite. Therefore, the anode used in the
Hall–Héroult process for the extraction of aluminum is made from graphite.