Mosjoen Potrooms
The potrooms are the heart of the smelting process as it is here that alumina, anodes, energy and other raw materials are added to the pots and are turned into liquid molten metal. The pot rooms in Mosjøen consist of two pot lines which are operated by teams of highly skilled pot room operators. The plant’s nameplate smelting capacity is 193,000 metric tons per year (mtpy).

To see an illustration of the smelting process, click here.

Producing molten aluminium

In the potrooms, the alumina is fed into a large carbon or graphite lined steel smelting cell known as a pot. The alumina is dissolved in molten cryolite, also known as aluminium fluoride or ‘bath’.

A high electric current is passed through the pot at low voltage via the carbon anodes which enable the alumina solution to split into its components of aluminium and oxygen. The oxygen reacts directly with the carbon anode, which gets consumed to form carbon dioxide that bubbles away and the aluminium collects at the bottom of the pot. The electricity also maintains the temperature of the pot at about 957 degrees Celsius. The aluminium is then siphoned from the bottom of the pot using a crucible and is then transferred to the the neighboring casthouse for casting.

Click image to enlarge.

Alumina delivery to Mosjoen