Recycled metals replace part of the needs previously provided by mines and reduce our imports, according to our partner The Conversation.
However, the rise of “all” recycling for all metals is taking a road strewn with pitfalls.
This analysis was conducted by Florian Fizaine, lecturer in economics at the University of Savoie Mont Blanc.
Popularized by the enthusiasm around the circular economy, recycling is on the rise.
Carrying the promise of a model operating in a vacuum and marking its independence from mining resources with an often denounced ecological balance sheet, recycling multiplies the theoretical advantages on paper.
This contribution of so-called secondary recycled metals replaces part of the needs previously provided by the mines (so-called primary metals), and therefore makes it possible to avoid waste and contamination associated with the mine while reducing our dependence on imports. of metals from potentially geopolitically sensitive countries.
From an energy point of view, a tonne of recycled steel, aluminum or copper is also less energy intensive than its primary equivalent – with energy savings ranging from 60 to 90%.
The volumes of recycled metals reintroduced into the loop, finally, are all materials that will not end up in landfills with the lot of pollution and costs that they could have generated.
However, and without even aiming for perfect circularity, the rise of “all” recycling for all metals is far from being so simple and is more of a road strewn with pitfalls.
How do we measure recycling?
Let's start by clarifying what is meant behind this broad concept of recycling.
Four different ways of evaluating it make it possible to apprehend it: the collection rate, the recycling efficiency rate, the recycling rate at the end of the life of the elements and the rate of incorporation of recycled material in the products.
The collection rate represents the quantities of metals actually collected each year out of the total flow that reaches the end of its life, while the recycling efficiency rate measures the quantity recycled over the quantity collected.
The product of these last two rates is equivalent to the recycling rate at the end of the life of the elements.
The incorporation rate, meanwhile, corresponds to the share of recycled material in the production cycle.
Each of these indicators has its uses.
To minimize the amount of waste to be managed in landfills, the recycling rate of end-of-life elements is more relevant, while to reduce the resources extracted from mines (and the associated energy consumed), act on the rate incorporating recycled material into products will have more impact.
If we exclude the possibility of a drop in the production of products (or an absolute decoupling), approaching a rate of incorporation of "recycled" of 100% requires a rate of recycling of elements at the end life of 100%.
Complex products
So far, the facts seem to contradict this goal.
A large part of the metals are not or only slightly recycled, this is the case for most minor metals (sometimes called rare metals, such as lithium, gallium or indium).
And well-recycled metals (steel, base and precious metals) have reached a plateau and are no longer progressing.
It would therefore seem that the all-recycled scenario comes up against the reality of products that are often: complex (number of components and elements), varied and whose metal concentrations – affecting both the costs and revenues of rebreathers – are not always favorable to the latter compared to conventional mining.
The diversity of products and components complicates the assembly of suitable recycling lines and their massification, especially since the short technological lifespan of certain products can completely render the previously relevant recycling model obsolete.
Thus, the very rapid replacement of compact fluorescent lamps by their LED equivalent in a few years put an end to experiments in the recycling of rare earths from the former, the treatable flows of waste being brought to dry up quickly.
Sometimes unfavorable economic conditions
To continue, the price of metals, but above all its associated volatility, is not always a very favorable ground for setting up recycling chains either, because this accentuates the uncertainty on the level of revenue.
Even if the prices of metals would reach high levels, various past studies have demonstrated the weak reaction of the secondary supply of metals to the price of the latter.
On the cost side, extraction from the “urban mine” is not necessarily an economic eldorado, particularly when one is interested in the concentration of minor metals.
For the latter, the concentrations of the urban mine are often very much below that of the conventional mine.
Combined with average prices, they represent only a minor fraction of extractable revenue, so it is not surprising that minor metals are not targeted by recyclers.
Then other studies have shown that the reduction upstream of the quantities of metals, in particular precious metals, in electronic products (in particular through miniaturization) has made the recycling model much less attractive.
There would then be a trade-off between, on the one hand, complex products with low concentrations of metals (therefore sparing in metals) but not very recyclable, and simpler products but more metal-intensive and therefore better recyclable.
The first R of the circular economy (i.e. decrease) would thus tend to drive out its last R (recycle).
Similar effects have been observed for photovoltaic panels whose reduced thickness (and concentration) would have unfavorable effects on the recycling of the metals contained.
Multiple constraints
Finally, there are also other obstacles, too long to develop here, of technological, cultural and legal orders which constrain the achievement of the recycled whole.
A bad reaction to these findings would be to disqualify the value of recycling.
On the contrary, recycling will have to be an integral part of a more sustainable economic model both from the point of view of resources and the environment.
Our "RECYCLING" file
As environmental science specialists constantly remind us, recycling is only a small part of the solution, and maximizing it is complex, difficult and sometimes incompatible with other levers of the circular economy.
Research therefore still has work to do to better understand how to resolve these constraints and propose new, more sustainable models.
This analysis was written by Florian Fizaine, lecturer in economics at the University of Savoie Mont Blanc.
The original article was published on The Conversation website.
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