The solid crust is routinely severed and the aluminium oxide

As the reaction continues, a solid crust constantly forms on top of the electrolyte. The solid crust is routinely severed and the aluminium oxide is constantly swirled to sustain its concentration. Aluminium is a little bit denser than the cryolite bath, hence it constantly forms deposits in a metal pool at the underneath the pot. Carbon dioxide is vigorously produced as oxygen reacts with the carbon anodes. The anodes are consequently being depleted in the process, therefore they are constantly lowered deeper into the bath and ultimately replaced on routine basis. The quantity of alumina lowers as the process of electrolysis continues. To maintain its desired level, alumina is added intermittently. Failure to do this may result in a condition called the “anode effect” whereby a gas film is formed around the anode. This film increases the current resistance and leads to high consumption of electricity. Correction mechanisms for this effect either consist of automatic or manual techniques that raise aluminium concentration in the cryolite bath. This practice is important as it results in process benefits and lowers the production of perfluorocarbons green house gases into the atmosphere.