Because aluminium doesn’t lose its atomic structure in the melting process, it can be recycled numerous times and in a lot of cases for the same product again. This is known as closed-loop recycling. The most common way to recycle the metal is to melt it. An example of how aluminium is recycled is by looking at the case of aluminium can recycling. Here is how it works:
- Recycling: You can recycle your cans in various ways. Take them to a can bank such as at your local supermarket, council recycling centre or shopping centre; use the doorstep collections offered by your council; cash from cans, which are schemes around the country, such as Alucan, in which you take part in aluminium can recycling for cash.
- Reprocessing: The cans are collected, checked for contamination and baled. The bales of cans are broken up and shredded into small pieces, about the size of a 50p coin. The printed decoration is removed from the cans through a process of blowing hot air onto them – at a temperature of around 500°C. The clean shreds are then melted in a furnace heated to 750°C. The molten metal flows into a deep pit where the casting process takes place. Cooled by direct contact with water, the metal then solidifies and an ingot is formed.
- Rolling: The ingots are transported to the rolling mill where they are pre-heated to 600°C and undergo their first ‘hot rolling’. They are then ‘cold rolled’ to the exact thickness required by the can maker.
- Can-making: The next stage is to feed the recycled aluminium sheet through a ‘cupping press’ which stamps out thousands of shallow cups, helping to create the can shape. They are then trimmed and washed ready to be printed.
- Filling: The cans are cleaned using high-pressure air and water. The air is extracted and at the same time the can is filled with carbon dioxide (CO2) and the liquid contents.
- Selling: The final stage of the loop is when the cans are delivered to the retailer ready for you to buy, drink and recycle all over again.