National Recycling Week – How do magnets play their part?

National Recycle Week is back for it’s 17th year! The week of celebration was put together by WRAP under the Recycle Now brand. The theme of the week changes each year and this years theme is ‘Together- We Recycle’. This years theme wanted to represent COVID-19 and recognise the sacrifices that our recycling and waste key workers and communities have made to recycling and their continued support to making the world around us a better place, even during a difficult time.

Did you know magnets have key roles in recycling centres? They are used in a variety of ways to help recycling plants separate materials efficiently. Find out more below…

Separation

Magnets are commonly used in recycling sites and do what they do best, attract ferrous materials! For example, tin, steel, iron, cast iron, and plate and structural steel. Magnets are found strategically along assembly lines where they will either be above or below the conveyor belt, extracting or holding the ferrous material down. Overband magnetic separators or extraction belts are used above conveyor belts to extract the ferrous materials up and create a new assembly line for the ferrous materials. Recycling centres follow strict guidelines and must separate metals and non-metal materials efficiently. This allows the materials to be processed in the correct way and repurposed for manufacturers use.

Fun example:

Toy Story 3! Can you remember the scene where we are led to believe that this is the end of the road for Woody and his friends, as the toys have found themselves trapped on a conveyor belt in a scrapyard? We watch in fear as the conveyor belt is leading them towards a shredder until… Buzz notices bits of ferrous materials (including Slinky) are being pulled out and attracted to a magnetic ceiling. They all scramble to find some ferrous waste, and with the help of magnets, they are able to escape the shredder.

Toy story 3 Image Source

Electromagnets

Electromagnets are used to lift and manoeuvre the crushed up ferrous materials or again to extract them from a pile of scrap. Ferrous materials are heavy and sharp but with the strength of the electromagnets they can be lifted and moved around with ease. Any material that is not picked up by the crane’s magnet gets sorted by the type of metal it is. Electromagnets are operated from an electrical current that is applied to the magnet, which effectively turns the magnet on, allowing the ferrous material to be held. To release, the electrical current is simply turned off. This means ferrous waste can be sorted quickly and efficiently.

Eddy Currents

It’s not just magnets directly that are used in recycling. Magnetic fields are also used for sorting through the materials. Recycling centres have many assembly lines for sorting through the various materials. Some of these assembly lines use an Eddy Current Rotor. This creates a magnetic field which repels non-ferrous metals, like an aluminium tin, to shoot forward to land into separate part of the production line. The non-metals is then left to simply fall off the belt due to gravity. 

“Where is my local recycling centre?”

If you are unsure where to recycle locally, please find this useful link below…

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