How and why are metals recycled?

If there is an abundance of aluminium, steel and cast iron, their industrial production is nonetheless highly polluting. From the extraction of critical minerals, often associated with deforestation and the pollution of natural environments (water and soils), to the transformation into end products, these metals generate a significant carbon footprint. Recycling constitutes an constructive answer to reducing these environmental impacts by decreasing demand for raw materials while saving energy.

Recycling metals subsequently helps limit the use of natural resources by reusing materials already extracted. And the issue becomes especially interesting when we measure the energy required for this extraction!

Another benefit: metals can be recycled many times : additives used in alloys can complicate the recycling process, requiring specific treatments.

As you can imagine, given the cost of recasting metals is clearly much lower than that of mining, the metals industry quickly positioned itself as a recycling pioneer.

Thanks to their magnetic properties, lots of metals are easy to retrieve and sort, subsequently facilitating their recycling. You get the picture, you need a (very) big magnet (and a whole recycling chain).
For aluminium, sorting is achieved thanks to an Eddy current separator (Eddy currents are like loops of electric currents that form in metal when subjected to a variable magnetic field), subsequently helping to separate them from other metals.
While initial doubts as to the quality of the recycled alloys have broadly been dispelled thanks to rigorous controls, there remain challenges to be met to optimise the recycling processes and guarantee the traceability of materials.

But… despite growing industrial demand and sorting made easier, there remains a limited supply of recycled materials. These metals are indeed often incorporated in durable goods such as vehicles or buildings … so you have to wait until the end of these types of durables' life cycles before the metal can be recovered!
While, of course, a good thing to rely on sustainable materials, you also have to factor in that metals recycled today were produced several decades ago.

This makes it easier to understand why available resources are insufficient to meet current demand.

Camping chairs, walking poles, aluminium water bottles... aluminium is a material easily found in the world of sport. Lightweight, corrosion resistant: it is an excellent material for producing sturdy products without adversely affecting their weight.

The aluminium we use every day comes from a rock called bauxite.
It undergoes several transformations: firstly, it becomes aluminium oxide, then after an energy intensive electrolysis process, it is turned into pure aluminium. It is worth noting that approximately 75 % of the extracted bauxite during these transformations is lost, with only a quarter ultimately transformed into aluminium.

Recycled aluminium comes from scrap metal recycling.After a sorting, cleaning and shredding process, the waste is remelted and refined to obtain aluminium whose quality is comparable to virgin aluminium. This process considerably reduces energy consumption (by up to 95 %) and greenhouse gas emissions from aluminium production by at least 18 %.

Cast iron, an alloy made from iron and carbon, is renowned for its robustness and impact resistance. It makes it the ideal material for objects subject to high pay loads, such as weight plates or dumbbells.

But… as you can imagine, as is the case with aluminium, iron ore extraction comes with a high environmental impact. Iron ore must be smelted in blast furnaces to become cast iron (then steel, then eventually, stainless steel).

Therefore, the benefit of recycled cast iron lies in the fact it limits the extraction of new mineral resources, thereby reducing the associated energy consumption by 40 % compared to virgin cast iron.
The end product is sports equipment, which is just as ready to withstand your training sessions.

Cast iron, an iron and carbon alloy, is the starting point in steelmaking. Transforming cast iron into steel involves removing part of its carbon, and other elements, such as manganese or chrome, are added to improve its mechanical properties. As a result, steel becomes resistant, more ductile (pliable), and easier to shape than cast iron.Despite these differences, both materials share common origins and similar environmental challenges linked to iron ore extraction and the transformation processes.
As with cast iron, we prefer recycled steel from scrap metal that has been sorted, cleaned, shredded, and remelted.As a result, the material thus obtained is enriched with alloying content, providing the same qualities as virgin steel.
By choosing recycled steel instead of its virgin equivalent, we use up to 40% less energy, all while limiting the extraction of new materials.

Stainless steel, a variant of steel, is obtained by adding chrome to the alloy, which gives it excellent corrosion-resistant properties. While the final composition differs, the production stages and environmental challenges are comparable.