100% of aluminium can be recycled. Secondary aluminium made from recycled materials, commonly referred to as green aluminium, uses up to 90% less energy during manufacture than virgin aluminium.

Aluminum producers need their secondary raw materials to constantly exhibit high levels of purity if recovered aluminium (recycled aluminium) is being utilised to create new products. Sorting is typically an effective solution to this problem. Aluminum is increasingly in demand as a lightweight, high-performance material. In order to reduce weight and hence energy consumption, aluminium is rapidly replacing traditional materials like steel, particularly in the engineering of automobiles. Due to this, the recovery of this metal is becoming an increasingly valuable technique.

Not all aluminium is the same

Aluminium scrap has a wide range of material compositions and fractions. It comes from a wide variety of built-in products and components. As alloy components, silicon, manganese, copper, zinc and magnesium increase the strength of the aluminium and determine the primary and secondary uses of plates, rods and tubes, etc. The composition of alloys also determines the ‘castability’ - which is an advantage for complex components such as alternators. The best castability is that of AlSi compounds (4000 class). In some cases, these also contain elements of Mg and Cu to increase strength.

Profiles, cans, plates etc. in wrought aluminium are normally low in alloy components and can be used in almost all secondary processes. In the mechanical recovery of wrought aluminium, the main task is separation of heavy metal components, which are exposed during shredding, e.g. by hammer mill or rotary shear.