Anode Plant
It all starts with dirt

Anodes are an important raw material in the potroom process. But did you know that it all starts with dirt? See an illustration of the process from bauxite to finished end product here.

History of the anode plant

The construction of the anode plant in Mosjøen started in 2006, and regular production started late September 2007. The baking furnaces supply the smelter in Mosjoen and the Fjardaal smelter in East Iceland with anodes.

Producing anodes

The anode plant in Mosjøen produces anodes for use during the aluminium smelting processes at two facilities; Alcoa Mosjøen and Alcoa Fjardaal.

Anodes are large carbon blocks which act as electrical conductors, heating and allowing electricity to enter the smelting pots. Anode production begins in an area of the smelter called the Green Mill. Here, an anode mix is produced from blended petroleum cokes, pitch and recycled anode butts that have been returned from the smelting process. These materials are mixed together in heated mixer boxes. Once the mixture is fully blended, the material is conveyed to a series of mechanically vibrated moulds. The formed anodes, known as "green anodes" are then conveyed to their respective furnace.

In the baking furnace, anodes are placed in an open top ring and ‘baked’ to a temperature between 1060 degrees Celsius and 1170 degrees Celsius. The total baking process, including handling, baking and cooling, takes around two weeks. The baking process converts the "green”, soft anodes into hard, electrically conducting anodes that will withstand the high temperatures and electrical currents in the potrooms. The Mosjøen smelter anode plant has 272 individual baking pits which can each hold 18 anodes.

The last stage of the anode production process takes place in the rod shop. This is where the anodes are rodded, i.e. the anode is fitted with a copper/steel rod using molten cast iron. The Mosjøen anodes are then transported via fork trucks to the potrooms for use in the smelting pots, whereas the Fjardaal anodes are transported to supply wessels in the Alcoa Mosjøen harbor, for shipping to Fjardaal in East Iceland.