Metals are versatile materials that have been used to make everyday materials for centuries. Metals are valuable non-renewable natural resources. They are strong, durable, malleable and conductive, and they serve as essential raw materials for a wide variety of uses, such as in the production of tools, in construction, and in electronics
Steel, aluminum 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.
How does metal recycling work?
Metals are among the best performing materials when it comes to recycling. Unlike some other types of recyclable materials, such as paper and plastics that tend to degrade their value over time and have a limit to how many times they can be recycled, metals can be recycled almost indefinitely and never lose their structural value.
Aluminum, 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 2014, more than 86 percent of steel was recycled .
Metal recycling is a booming industry; in the UK alone, it has reached an estimated £5.6 billion employing around 8,000 people.
There are also clear environmental benefits to metal recycling, specifically increased resource use but also carbon dioxide emission savings. For example, recycling one ton of steel saves 80 percent of the carbon dioxide emissions produced when making steel .
The process of metal recycling: What exactly happens?
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.
Step 1: Collection
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 specialized collection systems where consumers can have larger items picked up or where central locations where they can be dropped off.
Step 2: Sorting
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!
Step 3: Shredding
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.
Step 4: Melting
Once in tiny pieces, the metal is placed in a large furnace which is optimized for melting the specific metal to be recycled. Depending on the metal the recycling process can take a few minutes or several hours.
Step 5: Purification
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 this, but common ones are electrolysis or using powerful magnetic systems that separate the metal.
Step 6: Cooling and solidification
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 aluminum 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!
What are the benefits of recycling metals?
The following are some of the main benefits of recycling metals:
#1 Recycling metals helps to conserve natural resources and protect the environment
Metal ores are a limited resource, and by recycling metals such as steel and aluminum that are made from ores, we reduce the amount of raw materials that are needed to be mined from the environment.
Recycling one ton of aluminum saves 8 tons of bauxite ore, and recycling one ton of steel saves 2,500 pounds (1,134 kg) of iron ore, half a ton of coal, and 120 pounds (54 kg) of limestone .
By recycling one ton of steel, 40 percent of the water used for production is conserved, and 86 percent of air emissions and 76 percent water pollution are reduced. Recycling metals also reduces ore mining waste by 97 percent .
Since the process of extraction and the production of brand-new raw metal materials requires large amounts of energy, recycling metals helps to reduce greenhouse gases and other types of emissions. For example, the recycling of aluminum produces only 5 percent of the carbon emissions compared to those that are produced during the production of new aluminum from virgin materials .
The recycling of metals has the potential to cut the production of greenhouse gas emissions by 300 to 500 million tons. By reducing other types of emissions through recycling metals instead of producing them with virgin materials, we are also reducing polluting chemicals in our air that contribute to respiratory problems .
#2 Recycling metals saves energy
Since the production of metals from raw materials is so energy-intensive, such as through the drilling of ore and metal refining, recycling metals saves a significant amount of energy.
For example, the amount of energy used to make a single aluminum can could be used instead to recycle 20 aluminum cans. By recycling aluminum, we save over 100,000 gigawatt hours of energy, which is enough energy to power the entire country of the Netherlands .
Recycling aluminum saves 95 percent of the energy used to make new aluminum, recycling steel saves 60 percent of the energy used to make new steel, and recycling copper saves 90 percent of the energy used to make new copper [3,4].
#3 Recycling metals helps the economy
By recycling metals, we help to support an industry that creates jobs and helps our local economies. Metals are highly valuable, and by recycling them, we are helping to provide raw materials that can make new products, and the job opportunities that go with them. Workers are also needed to collect recycled materials and to process them so that they can be used again.
In the U.S. alone, more than a million people are employed by a recycling industry that generates $236 billion per year .
Because metals are so important for many of the things that we do, it is important to continue to reuse them so that they will be available for future use. For the sake of our environment, health, and economy, it just makes sense to recycle metals instead of throwing them away.