Aluminium recycling is the process by which scrap aluminium can be reused in products after its initial production. The process involves simply re-melting the metal, which is far less expensive and energy intensive than creating new aluminium through the electrolysis of aluminium oxide (Al2O3), which must first be mined from bauxite ore and then refined using the Bayer process. Recycling scrap aluminium requires only 5% of the energy used to make new aluminium. For this reason, approximately 31% of all aluminium produced in the United States comes from recycled scrap. Used beverage containers are the largest component of processed aluminum scrap, with most UBC scrap manufactured back into aluminum cans.
A common practice since the early 1900s and extensively capitalized during World War II, aluminium recycling is not new. It was, however, a low-profile activity until the late 1960s when the exploding popularity of aluminium beverage cans finally placed recycling into the public consciousness.
Sources for recycled aluminium include aircraft, automobiles, bicycles, boats, computers, cookware, gutters, siding, wire, and many other products that need a strong light weight material, or a material with high thermal conductivity. As recycling does not transmute the element, aluminium can be recycled indefinitely and still be used to produce any product for which new aluminium could have been used.
The recycling of aluminium generally produces significant cost savings over the production of new aluminium even when the cost of collection, separation and recycling are taken into account. Over the long term, even larger national savings are made when the reduction in the capital costs associated with landfills, mines and international shipping of raw aluminium are considered.
Recycling aluminium uses about 5% of the energy required to create aluminium from bauxite; the amount of energy required to convert aluminium oxide into aluminium can be vividly seen when the process is reversed during the combustion of thermite or ammonium perchlorate composite propellant.
If energy is directly equated to carbon dioxide, then recycled aluminium could be said to create 5% of the carbon dioxide produced in the creation from raw materials. In practice, this cannot be assumed. Electrolysis can be done by electricity from non-fossil-fuel sources, such as nuclear, geothermal, hydroelectric, or solar. Aluminium production is attracted to sources of cheap electricity. Canada, Brazil, Norway, and Venezuela have 61 to 99% hydroelectric power, and are major aluminium producers.
The vast amount of aluminium used means that even small percentage losses are large expenses, so the flow of material is well monitored and accounted for financial reasons. Efficient production and recycling benefits the environment as well.