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Recycling rare earth metals

Usual ill informed rant at The Guardian about the recycling of electronics and rare earth metals. My reply in the comments there.

Oh dearie me. This is just the standard rant about mining and recycling with \”rare earth metal\” dropped in every so often.

There\’s absolutely no understanding at all about what a rare earth is, why they may or may not be recycled, what other metals are or are not recycled and why.

The rare earths are the lanthanides, Cerium to Lutetium (sometimes we add Sc and Y as well). These tend to be used in tiny quantities. For example, a computer might use 6 grammes of neodimium in the magnets in the hard drive. That means that if we collect 1 million computers, extract the hard drives, take them apart and extract the correct part of that drive then we\’ve accumulated 6 tonnes of neodimium.

If we had 6 tonnes of brand spanking new neodimium, ready to be used to make magnets again (some processing would be required to get our scrap to this point) then the value would be around $1.8 million at today\’s prices.

So, why don\’t we recycle the magnets from hard disk drives? Because, even if we had a pile of 1 million computers, the cost of taking out the magnets from the hard drives would be more than $1.8 million.

It takes time to extract them, you see? Human labour time. Labour that has to be paid for from the amount we get from recycling those magnets. And the value of the metals recycled is lower than the value of the human labour we have to put into it.

Please note, this is using the vastly inflated prices of the current bubble in rare earths. A few years back and a few yeasr in the future, the value of that neodimium was/will be more like $180,000. At which point it\’s not even certain that we\’d cover the energy costs of re-smelting the Nd, let alone the labour costs. (We can\’t just melt down the magnets and recast them. We\’ve got to extract the Fe, the Nd and the B separately and then recombine them again, sorry, but we do).

Now, when we\’ve a windmill motor magnet, which might have 600 kg of Nd in one motor alone, oh yes, believe me, we do recycle it.

Just as we recycle the lutetium from an MRI machine, as we\’ve a nice 50 kg crystal there. But not the Tb from the inside of a cathode ray tube as we might have 2 grammes there.

The great problem of recycling anything is that whatever it is that you\’re after might be extremely dispersed. You can end up epending more energy, more labour, in trying to oncentrate it enough to recycle it than you would expend by simply digging up some new stuff.

Other metals in computers we do recycle. The copper and gold on the motherboards for example, I could walk you through dozens of plants in Europe which recycle these. And yes, some of this waste does get exported to places where children scramble over it to extract them.

The reason? The regulations in Europe make it very expensive to do this extraction. The more you try and make recycling perfect, make sure there is no pollution at all from it, that everything, not just the stuff rich in metals, is recycled, the more the temptation there is for crooks to side step that recycling system.

No, I\’m not defending the crooks, just pointing out the obvious. What we actually want is to be treading that very fine line, recycling as much as we can but making sure that recycling is profitable. That hunger for profit will mean that people will actively seek out ways of recycling equipment here in Europe. Weirdly, if we relaxed the recycling standards, we\’d probably see more recycling.

But back to the basic error in the piece. No understanding is shown of the problem of dispersion. And dispersion is the basic underlying economic problem of all recycling.

When our metals are in tiny amounts, dispersed through hundreds of millions of tonnes of material, that material spread out all over the place, it costs more to collect and process the material (that is, we use more resources to do this) than simply going and getting new stuff.

When the metals are more concentrated then it does make sense to treat them as a resource that we can extract metals from. An old car is at least a few hundred kg of steel, maybe 40 kg of copper etc, worth recycling for the metals content. Old mobile phones are worth grinding down and using as a tantalum ore (yes, this is done, Ta ore is currently $120 per lb Ta2O5 contained). Old windmill magnets, 600 kg of NdFeB on the hoof, yes, recycled. Old disk drives, 6 g of FeNdB? No, dump it, we\’d use more resources than we get trying to get it.

Sorry greenies, but until you start looking at the economics of metals recycling you\’re just not going to understand why some things get recycled and others don\’t.

13 thoughts on “Recycling rare earth metals”

  1. “It takes time to extract them, you see? Human labour time. Labour that has to be paid for from the amount we get from recycling those magnets. And the value of the metals recycled is lower than the value of the human labour we have to put into it”
    Of course workfare is human labour that pays for itself (as some of them stop claiming benefits!)

  2. Grauniad journalists know very little about science. This issue, as Tim will know has been around for a very long time. The famous German chemist, Fritz Haber (he of the Haber – Bosch ammonia proceess) tried to pay off German war debts in the 1920s by extracting gold from seawater.

    “Thus, in 1920 Haber had the idea of paying off the (German war) debts by gold resources obtained from electrochemically extracted gold which was assumed to be dissolved in sea water in relatively high concentration. Together with a secret task force team he developed methods to extract gold from sea water as well as new techniques for its analysis. This included detailed studies of sea water samples from various parts of the world, some of them obtained by marine expeditions undertaken only for this purpose. After several years of research it was found that the initial, very promising analysis (it was estimated that 8 billion tons of gold were dissolved in the sea) had yielded gold concentrations which were too high by a factor of 1,000 rendering the extraction economically impracticable.

  3. “Of course workfare is human labour that pays for itself (as some of them stop claiming benefits!)”

    Try telling that to the unions negotiating their contracts

  4. I love some of the comments, e.g.

    “My computers work long hours because I do; they usually seem to give up the ghost in year three. Odd that TVs can last a decade, but computers apparently ‘can’t’.”

    Maybe because there are mechanical moving parts in computers?

  5. Agree with all of that Tim. And I’m going t0 recycle the P.J. O’Rourke comment yet again (which I think he got from Jerry Taylor), that “no has to pay you to recycle Ferraris”.

    If something is worth recovering, it will happen. If not, it won’t.

  6. View from the Solent

    “Maybe because there are mechanical moving parts in computers?”

    Much more likely is that the EU banned lead-based solder 5 years ago. The replacements are prone to ‘whiskering’ – formation of long, thin filaments which cause shorts.
    I’m typing this on a +8yr-old box which has run continuously for the last ~5 years.

  7. 50Kg of Lutetium in an MRI machine?


    That’s something I’ve learned today, thanks Tim.

    Tim adds: Bit over the top actually, more like 10 kg. But it’s what converts the changes in magnetic fields into a change in an electrical current so you can paint the images on a screen. I think it’s called “magneto-electric”, the lutetium crystal? All made in Texas anyway.

  8. I understood “best practice” is to replace (say) HDDs every three years?

    Although I loath the term “best practice” (because there is always something better than whatever the consultant is calling “best”), the rate of improvement in desktop computing devices is such that it is rarely cost-effective replacing parts once the warranty expires. Just replace the whole thing.

    Certainly, when I was involved in buying large numbers of the things, by the time it was on anybody’s desk, it was obsolescent.

  9. MRI scanners? Are you sure? I thought it was used in PET scanners. “Turning magnetic fields into electrical signals” is the job of a coil (or more exotically, a SQUID.) The signal from the receiver coil goes into a pre-amp and then into the Fourier processing gear which deconvolves the information to give you back the image.

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