when it comes to recycling. Aluminium, steel, gold, silver, brass, and copper are just some of the metals that can be and are recycled. In fact, steel is the most recycled material on the planet; in 2012, 88% of steel was recycled[sc:1] whereas worldwide, over 400 million tonnes of metal are recycled each year[sc:2].
Metals are versatile materials that we have been using to make everyday materials for centuries. Steel, aluminium and copper are some of the most widely used metals but recent technologies such as smartphones have created a market for rare earth metals, which as the name suggests are not only rare but also expensive. Given that metals are not a renewable resource, recycling has emerged as a very efficient way to retrieve metal from existing products when they reach the end of their lifecycles and recycled into new products. Metal recycling is a booming industry; in the UK alone it has reached an estimated £5.6 billion employing around 8,000 people[sc:2]. There are also clear environmental benefits to metal recycling, specifically increased resource use but also CO2 emission savings. For example, recycling one tonne of steel saves 80% of the CO2 emissions produced when making steel [sc:3].
With the majority of our everyday objects containing some sort of metal, it is worth knowing a bit more about what happens when they leave our doorstep for recycling.
The first thing in metal recycling is, as with every recycling process, the need to ensure that the metal gets to our recycling bin. In many cases, articles containing metals are complex or large objects such as electronic and electrical equipment, white goods or cars. To help collection of these objects, producers and retailers often set up specialised collection systems where consumers can have larger items picked up or where central locations where they can be dropped off.
Once collected, the metals are sorted to make sure that those that can be recycled undergo that process and to also ensure that only items of a high quality enter the recycling process. This will ensure a high quality recycled product. The sorted metal is then processed and essentially squeezed together so it occupies less space when it goes on the conveyor belt, on its way to be recycled!
The bails of metal are then shredded and broken down to tiny pieces. This is the most important preparatory step as the metal will need to be melted. In smaller pieces, the metal can be melted in lower temperatures. Once in tiny pieces, the metal is placed in a large furnace which is optimised for melting the specific metal to be recycled. Depending on the metal the recycling process can take a few minutes or several hours.
The next step is the purification process which ensures that the final produce if free of any impurities and of the highest quality. There are several methods to do that but common ones are electrolysis or using powerful magnetic systems that separate the metal. The melted metal is then carried out to a cooling chamber so it can solidify. The metal can solidify in different shapes depending on how the metal will be used. Usually, steel solidifies in steel blocks whereas aluminium is cooled into sheets.
Once the metal has cooled, it is ready to be sent off to a manufacturing site where it can be integrated into a brand new product. And that’s the metal’s lifecycle!