Aluminium Recycling Guide
Recycled aluminium has the same properties as newly-produced aluminium - but it only takes 5% of the energy to produce it.
Unlike some metals, aluminium, can be reprocessed and reformed endlessly, while losing none of its quality. This constant process is known as closed loop recycling. In this guide, you can find out more about the recycling of aluminium process, its benefits and how much it can cost.
Aluminium Recycling Process
There are a number of steps taken in recycling aluminium. Household aluminium packaging - such as drinks cans, food tins and foil - is collected and taken to a waste transfer station. This is divided from other types of waste, often using an eddy current separator.
Prior to reprocessing, the material needs to be sorted and cleaned. At the reprocessing plant, the metal is shred using a metal shredder and compacted into bales using metal baling machinery .
The scrap aluminium is then melted, turning it into molten aluminium. Aluminium scrap can contain impurities, so in the melting furnaces, salt fluxes are added in order to cover the metal to remove impure coatings and inks. This also helps protect the material from oxidisation.
Following the melting stage, the metal is transferred to holding furnaces. Here it can be further refined, through process such as de-gassing and de-magging.
The molten aluminium is then pressed into ingots which, in turn, are sent to rolling mills in order to be rolled out and turned into sheet aluminium. In sheet form, aluminium has greater flexibility and strength, and is ideal to then be made back into various types of aluminium product.
Benefits of Recycling Aluminium
The benefits and advantages of recycling aluminium can be seen in four broad areas - environmental impact, energy saving, economic benefits and costs.
1. Environmental Impact of Recycling Aluminum
The primary environmental benefit of recycling aluminium is the decreased need for mining bauxite. However, there is also an environmental impact when it comes to carbon dioxide emissions. The extent of this depends on the type of energy used; for example, electrolysis can be done using a number of different fuel sources, such as geothermal, solar or nuclear.
Some air emissions and solid waste (e.g. dross and skimmings) may be generated in the refining process. However, these materials are also processed in order to recover the metal, as this often takes place in the same reprocessing plant.
2. Energy Saving
Energy saving is the biggest benefit of recycling aluminium. Approximately 95 percent of energy is saved by recycling aluminium, as the transformation of scrap into recycled alloys requires just 5% of the energy that would be needed to create a similar product from raw materials.
3. Economic Benefits
Importantly, aluminium recycling creates jobs, such as in foundry operations, smelting or various roles within aluminium processing. This in turn means that the aluminium recycling industry delivers a direct, positive economic output - in the US, it is estimated that the aluminium industry supports $186 billion in economic output.
4. Cost of Aluminium Recycling
As recycling requires far less energy than extraction, the cost of recycling aluminium is comparatively cheap. This is the case even when the cost of collection and reprocessing is taken into account, including costs related to energy, transportation, sorting and handling. As raw material costs are approximately 50% of the cost of finished aluminium, extracting aluminium is certainly far more expensive than recycling.