History of Aluminium

Aluminium accounts for 8% of the mass on the surface of the earth. It took long time before one could produce the base metal since aluminium is found in very stable oxygen bindings.
The first one to manage it was the Dane, H.C. Ørsted in 1824. It was then that the commercial production of the metal started but for a long time, aluminium was a more sought after metal than gold.

The breakthrough came in 1886 when the American, C.M. Hall and the Frenchman, P.L. Heroult found their own methods of producing aluminium by electrolysis. This method was based on the use of aluminium oxide that was produced from bauxite. Even today, it is the same method, known as the Hall/Heroult method, which is being used.

Around 1918, a Norwegian, C.W. Søderberg, discovered a 'continuous anode'- Søderberg technology. SØRAL does not use this technology but instead the ready-to-use anode blocks- pre-baked anodes-'pre-baked technology'.

OUR PRODUCT IS ALUMINIUM EXTRUSION BILLETS

Explained in extremely simple terms, it may be stated that 4 kg of bauxite = 2 kg of aluminium oxide = 1 kg of aluminium.

SØRAL utilises only pre-baked technology in the aluminium process. We produce aluminium in an electrolysis process.
Aluminium oxide is dissolved in a “bath” of cryolite. At a current flow with a current intensity of 150 kA, a coat of liquid aluminium is deposited on the bottom of the electrolysis cell (the furnace). The temperature should be 960°C during this process. Around 14,500 kWh are used to produce 1 tonne of aluminium.

The cast house is the last link in the production chain. Today the cast house has two casting units, casting all the metal as extrusion billets. After the addition of alloy metal the metal from the electrolysis is cast in billets 7 metres long, with diameters ranging from 178 - 317 mm.

The billets are heated and cooled in a homogenisation process to ensure that they obtain the correct metal structure. The billets are then sawn and packed and taken to the quay for shipping.

Aluminium for future generations.

Next to steel, aluminium is the most commonly used metal in the world. It weighs only a third of steel, has relatively high strength and is easily workable. It is resistant to corrosion and is a good conductor of electricity and heat. At the same time it can be remelted and recovered.

”Around 8% of the earth’s crust consists of aluminium / The supply is practically unlimited and the average degree of recycling is 73% and increasing.”