[ExI] not that rare earth (part 2 of at least 2)

[spike at rainier66.com]

From: spike at rainier66.com <spike at rainier66.com> 



 

From: John Clark <johnkclark at gmail.com <mailto:johnkclark at gmail.com> > 
Subject: Re: [ExI] not that rare earth (part 2 of at least 2)

 

On Tue, Oct 28, 2025 at 4:59 PM spike jones via extropy-chat <extropy-chat at lists.extropy.org <mailto:extropy-chat at lists.extropy.org> > wrote:

 

>>… these efficiency specifications are not strictly necessary,

 

>>…Without rare earth metals wind power would not be economically viable… And all this was true before China put a stranglehold on rare earth elements. …John K Clark

 

 

>…I see contradictory reports on this.  I don’t see sufficient evidence that China really has any stranglehold on rare earth elements.  The USA produced those before they became a big deal…  spike

 

An insight occurred to me today that really annoys me for not having thought of it before, being a minor-league chemistry hipster.

 

Metallurgy is still black magic after all these years.  There are arbitrarily many alloys and their characteristics vary slightly.  Permanent magnets are iron with a few traces of other stuff, but we know why the “rare” earth elements are good for a permanent magnet: they are large atoms, which helps hold things in place, reducing hysteresis in a reversing magnetic field.  

 

Straight iron can be made into a good magnet, but with a few large atoms mixed in there holding things steady, they make better atoms.  Those big atoms are chemically very similar to each other, and don’t form bonds with the iron.  They just sit in there and allow electrons to come and go as they will.  I think of them as little sticky capacitors in there kinda, a capacitor for magnetic fields rather than electric fields.  Don’t push the analogy too far, but consider the insight it offers.

 

Look at your periodic chart.  The actinides can be substituted for the lanthanides without the magnet noticing, for they behave nearly identically to the element above it (if it an actinide (actinium behaves chemically just like lanthium, thallium like cerium, protactinium just like praseodymium etc.

 

OK, well that explains why these elements are such a pain in the ass to purify: they are so similar chemically that their differential solubility is very low.  It takes a lot of purification cycles to clean it up.

 

But that observation leads to the insight.  We can also go up a row from the lanthanide series.  Lanthanum acts like yttrium, cerium like zirconium, praseodymium like niobium etc.  The lanthanide periods act like their counterpart one row up in the alkali metal period.  (This brings up a question in itself: we misuse the term period at the end of a sentence for emphasis, but what if… you actually need to end a sentence without emphasis with the term period?)

 

My insight: the reason we have rare earth magnets is that they provide a patent factory.  Any metallurgist can swap out a trace of this element for a trace of that element, measure its characteristics, hardness, magnetic properties etc, then name it after himself and claim a patent.  It isn’t magic at all, and doesn’t require any actual… like… brains.

 

So now we end up with all these “rare” earth magnets which don’t even require lanthanides or actinides.  The car makers recognized this years ago and phased them out, not wanting to pay others for their silly phony patents on permanent magnets, when the car makers figured out they can make their own permanent magnets without the exotic stuff.

 

That would explain why Tesla wouldn’t tell us how much “rare” earth elements are used in their cars, and why they phased them out quietly: they didn’t need them and they couldn’t trust China.

 

Compare that with the commentary we have been seeing in the news about China having a monopoly on rare earths.  View it from the chemist’s point of view and the speculator’s point of view rather than the New York Times, who try to convince us how desperately we need Chinese raw materials.  We don’t.  We never did.

 

spike

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20251031/2bba290a/attachment.htm>