Over 400 million tonnes of metal are recycled each year. Almost all metals can be turned back into metals of equivalent quality, but steel, aluminum and copper take the lion’s share of metal recycling. Recycling metal has benefits for everyone; it saves energy; uses fewer natural resources (why dig more out of the ground when you’ve already got the finished product?); and reduces CO2 emissions. It’s estimated that by recycling metals we’re stopping 200 million tonnes of CO2 going into the atmosphere each year.
Metal recycling has a number of distinct advantages over recycling other materials, such as paper, rubber or plastic. Firstly metals tend to be high value products to start with. They cost a lot of money to extract, refine and then produce a finished product, so it’s definitely worth recycling it if possible.
Secondly, far less energy is used in recycling metals than is used in mining them. For example, recycling a metal like steel saves 74% of its energy, while recycling aluminum and copper save around 80-95% of their energy.
And finally most metals are 100% recyclable, and unlike paper or plastic lose none of their physical or chemical characteristics during the recycling process. So while paper can only ever be turned into a product of lesser quality and value, metals can be turned into products of equal, or even higher value (it can be upcycled).
Steel is the easiest metal to recycle thanks to its magnetic properties. Large electromagnets are passed over waste streams, pulling the steel products free. This is a very effective method of extraction, and recovery rates of up to 85% are achievable. Once separated from the rest of the garbage, the process of making new steel is straightforward. Scrap steel is fed into a large furnace (scrap generally accounts for around a quarter of the total content), molten iron is added and steel is formed. This is then cast into ingots which can be manufactured into new steel products.
Like steel, aluminum also has a high value which makes it cost-effective to recycle. The process is similar to recycling steel; aluminum cans are shredded into coin-sized pieces, then any paint is removed by blowing very hot air over them. The clean pieces are then melted a furnace and the molten metal is made into ingots which can then be turned back into cans. Once used and put into a recycling bin, the whole process starts again. The recycling process is so efficient that aluminum can go from ingot to can and back to ingot in around 60 days.
After iron and aluminum, copper is the third most popular metal to recycle. Recycled copper has about 95 % of the value of newly cast metal, and 80% of all the copper ever mined is still in circulation today.
Despite all the advantages of recycling waste metal, much of it still goes to landfill, often in the form of waste packaging – would you for instance think to recycle the aluminum wrapper around a chocolate bar? Probably not. But it’s metal and can be recycled, so it’s important to consider all aspects of your garbage and really see what can be recycled, rather than thrown into landfill. -MARK LEE