Recycling metal is a cornerstone of sustainability, playing a critical role in conserving natural resources, reducing environmental damage and saving (a lot of!) energy.
Metals are unique in that they can be recycled indefinitely without degrading in quality, making them a highly sustainable material that can be used almost endlessly! From the soda can in your hand to the steel beams supporting skyscrapers, recycled and recyclable metal is all around us.
But how does the metal recycling process work? If you’re familiar with the way that paper is recycled, or even how textiles and plastics are recycled, then you may have a guess on how it all goes down already: collection, sorting, shredding, purifying and reforming. Here’s how it all works!
The metal recycling process
Collection
Like most other recycling processes, the metal recycling journey begins with collection.
Scrap metal is sourced from households, industries, construction sites and from discarded products like old appliances, cars and electronics. Household recycling programs and scrap yards make it easy to contribute small metals like aluminum cans and tin food containers, while larger industries supply more significant metal scrap from manufacturing offcuts or demolished structures.
One of the main challenges at this stage is contamination, as metals are often mixed with non-recyclable materials like plastic or coatings in collection bins. Careful collection practices (and diligent sorting) ensure the right materials enter the recycling stream and that waste is minimized along the way.
Sorting
Once collected and brought to a recycling facility, the next step is sorting the metals into categories based on their type and quality: categories like, for example, ferrous metals (as in, metals with high contents of iron) like steel and iron and non-ferrous metals like aluminum and copper. Magnetic belts extract ferrous metals (since they themselves are magnetic) while eddy currents and advanced sensors sort the remaining non-ferrous metals.
Proper sorting is vital to maintaining the purity and value of the recyclable metals — mixing different metals can degrade the quality of the final product, limiting its usability and ending the metal’s life cycle then and there.
Processing and shredding
After the sorting process is completed, the metals undergo processing to remove any impurities and prepare them for recycling. This often includes removing any coatings, paint or insulation still stuck to the materials.
The metals are then shredded into smaller pieces to increase surface area, which makes melting them more efficient. Aluminum cans, for example, are flattened and shredded into small flakes that are ready to be melted into a new form.
Shredding not only speeds up the recycling process, but also makes it easier to transport the materials to recycling facilities!
Melting and purification
Once the metal is sorted, cleaned and shredded, it’s finally ready to be melted into new items!
Each metal type requires a specific temperature and melting process in order to properly liquify. Aluminum melts at around 660°C (1,220°F), while steel requires temperatures exceeding 1,500°C (2,732°F)! A recycling center may only be able to melt certain metals depending on what equipment the facility has access to.
Melting the metals isn’t the end of the story, though — the molten metals also have to be purified using methods like electrolysis, chemical treatments or air blowing in order to make the re-formed metal as strong as possible.
Solidification & molding
Once purified, the molten metal is poured into molds and cooled to form more manageable pieces like ingots, bars or sheets. These raw forms are then sold to manufacturers and integrated back into the supply chain as they’re melted once again to be molded into new items.
Why recycling metal is important
The metal recycling process ensures that metals re-enter the economy rather than ending up in landfills, where they could take hundreds of years to decompose! Since the physical makeup of most metals means that they can be recycled almost indefinitely (unlike, say, paper or textiles), recycling metals is one of the smartest actions we can take when dealing with industrial, mechanical or technological waste.
Recycling metals also significantly reduces greenhouse gas emissions. For instance, producing recycled aluminum uses only 5% of the energy required for primary production (as in, starting from scratch!), reducing emissions by up to 92%! Similarly, recycling one ton of steel saves 2,500 pounds of iron ore and up to 1,400 pounds of coal.
Economically, recycling creates jobs in collection, sorting, and processing. It also reduces costs for manufacturers, as recycled metal is often cheaper than virgin material. These savings can be passed on to consumers, further incentivizing participation in recycling programs.
Although the average Joe isn’t contributing several tons of steel on a weekly basis, we all go through a fair amount of metal in our daily lives that can be recycled rather than tossed into a landfill. Soda cans, beer cans, sparkling water cans, tinfoil, tuna tins, old tech, DIY project scraps, you name it! They can all be recycled and turned into something brand new over and over and over and over and over and – you get the picture.
Check with your city’s local recycling program to see how you can best recycle your metal products, and you’ll be surprised at how much you can save!
Good luck!
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Featured photo by Eric Prouzet on Unsplash