Only 5% of the energy needed to produce primary (new) aluminium is needed to recycle scrap (old) aluminium back into new aluminium.
Recycling aluminium conserves significant amounts of energy – it reduces the carbon footprint of the material by reducing the impact of bauxite mining and the energy production required for primary smelting.
Aluminium can be recycled infinitely without any loss of its properties. This also applies to the copper, magnesium, manganese, chrome, silicon and other elements used in making aluminium alloys. So when an aluminium alloy such as a 6 series extrusion or plate is recycled, its alloying elements are retained and also recycled.
“Closed loop recycling” delivers maximum energy and resource efficiency.
One of the best examples of closed loop recycling is the aluminium beverage can - shown in the diagram below. See also the lifecycle of aluminium diagram in the About Aluminium section
Bauxite is the ore which contains aluminium. It is found in surface deposits in mainly tropical regions. Aluminium is the third most common element in the earth’s crust.
Mined bauxite is refined into alumina – a white powder which is essentially aluminium oxide. Refineries are typically located close to the bauxite mines.
Primary smelting is an energy intensive process in which aluminium is extracted from the alumina. The purity of the primary aluminium produced is of the order of 99.5%.
Primary metal is alloyed and cast into rolling slab or extrusion billet in a casthouse. Casthouses are typically located at the smelter or at the rolling mill.
The rolling slab is rolled into sheet of different alloys and properties – can end sheet and can body sheet. Can end sheet is coated with a lacquer
The can manufacturer produces the can ends and tabs from can end sheet. In a separate process, the can body sheet is drawn into the can body using specific tooling. The can body is then decorated with the beverage company’s brand graphics.
Cans are filled by beverage companies and the can end is then seamed onto the body to seal the can, thereby preserving its liquid contents.
The beverage in the can is typically consumed within a few months, and consumers then play their role in ensuring the empty can reaches a recycler.
Aluminium cans are sorted from among the other packaging items they are often collected with. Cans are sorted by hand or using mechanical extraction equipment.
The aluminium scrap is shredded and processed further to remove all contaminants (plastic straws, dust, dirt and other foreign objects).
Special furnaces remove the can's paint and lacquer and then melt the shredded can scrap – along with other manufacturing scrap from the canmaker. The resulting liquid metal is transferred to another furnace for final alloying and casting into new rolling slab.