It's important to contextualise this, it is probably the most important part of the entire story. Rare earths aren't all that rare, they generally have a crustal abundance comparable to copper. The question of where rare earth mining & processing happens is mainly one of price. Or, accounting for second order effects, a question of environmental regulations.

Are there any other contenders or did this come with any guarantees of this yet another example of oneside public-private partnerships?

If you want to keep industries like this, you are basically arguing that taxpayers should subsidise them-- the jobs you retain are not a straightforward net gain, you pay for the wage difference in tax money (or price, where typically the consumer foots the bill, which is often just like a rather regressive tax).

There are good arguments that this is simply necessary for absolutely vital industries like agriculture, which gets a generous ~$20 billion/year to stay local. But it is clear to me that this is not something that you can do for every industry-- that would basically amount to a small-scale planned economy (with all its drawbacks), would be very likely to poach talent from sectors that are actually "more valuable" according to market consensus, and would also be likely to provoke retaliatory actions by international trading partners.

For this specifically, I think throwing some hundreds of millions of taxdollars around to keep/reestablish the industry is probably a good deal, but it is rather obvious to me that you have to draw the line somewhere; spending hundreds of billions to maximize autarky would be a really bad idea even though it is easy to make it sound universally good ("local jobs! supply chain safety! trade balance!").

Would they have been able to hit a competitive price while maintaining environmental regs and paying a domestic workforce, would china end up the only other supplier in the world? Can government subsidies be counted on to last multiple administrations?

National security considerations can adapt to market forces by either directly subsidizing the domestic product (so that it will be as cheap as the foreign product) or establishing tariffs on the foreign product (so that it will be at least as expensive as the domestic product) or by outright banning the import of the foreign product (so that only the domestic product competes in the domestic market).

- USPS - literally written into the Constitution

- Passenger rail - Amtrak keeps pudding along even though financially it doesn’t make sense.

- Merchant marines - cargo is cheap. And cheaper in flag countries with lax labor rules. Yet, we maintain a expensive flotilla.

The iron nitride magnets require a special crystal structure, which is not the most stable for that material, so it is difficult to find processing methods so that the material will have that crystal structure and even if the structure is produced, it might revert in time to a more stable structure, which does not have the desired magnetic properties.

Like typical for such startups, that company does not say anything about which are the roadblocks that have prevented them for so many years to make iron nitride magnets until now, but it is pretty certain that their patents are bogus and the methods described there have not been usable for making what they claim to be able to make.

Lynas Rare Earths who are the largest miner and processor outside of China are in the initial stages of building a plant in Texas (which includes funding from the DoD). They currently have plants in Kalgoorlie and Malaysia, but not end-to-end making magnets.

Iluka have also secured the additional funding required for a processing plant in Australia and have deals with other miners for feed stock once they get going.

Disclaimer: I own shares in the above two and others and all currently at a loss on my initial investments.

The very recent turn of "we must literally own this territory" has been the surest possible way to create a crisis where none existed.

Interesting to note that there is quite big movement towards rare earth free electrical motors in the last few years that rely only on cheap, readily available materials. Some expect that to grab up to 30% of the market in about a decade. Similar technology is also being used for creating wind generators that don't depend on these expensive/rare materials.

In all applications where it is possible to use motors without permanent magnets, that is usually done, because the motors without permanent magnets are normally cheaper.

If you had read the article you’d know they have their own mine: “Hardly any firms, even in China, do what MP is attempting: produce finished magnets starting with ore that the company mines itself” Mostly China doesn’t mine materials but has concentrated the refining capacity in China for many commodities. Thankfully, we do have backup capacity so we won’t be totally screwed if China cuts us off, and the refining technology is well understood and in a conflict we or our allies can cut them off from many raw materials so their refining advantage isn’t a checkmate.

For high torque density applications, heat dissipation is often the limiting factor on duty cycle.

Also, the slip rings capable of passing high current to an electromagnet rotor are expensive and less robust than permanent magnets.

Essentially: it’s possible but I haven’t seen an application where it’s practical.

I see on their site now that they are building a plant that is expected to produce 5 (five) tons of magnets per year (compared to 1500 t/year for the plant discussed in the article or with 25000 t/year for the biggest of the around 300 Chinese plants).

Such a small-scale production might be enough only to make samples to distribute to potential customers, to convince them to design products using such magnets.

I will be pleasantly surprised when Niron Magnetics will be able to produce even those 5 tons of magnets.

I have already forgotten how many years have passed since I have seen for the first time Niron Magnetics claiming that they will start soon the production of iron nitride magnets.

Certainly there are more than 5 years since then, perhaps almost 10 years.

Their first patents, in which they have claimed to know how to make iron nitride, have been issued 10 years ago. Their inability to actually produce such magnets demonstrate that at least the claims of the first patents were false.

The language that is used in patent law is that patents "teach" how to do something that was unknown and non-obvious for those who were experts in prior art.

I am pretty sure that the patents of Niron Magnetics do not teach anything, but they are the kind of patents filed by those who want to do something, but they have no idea how to do it, so they file bogus patents with overly broad and inaccurate claims, as a preventive strike used to block any competitors to introduce that kind of products, in order to gain for themselves time to actually discover how to make in reality what they want, in a very different way than described in their fictitious patents.

If iron nitride magnets are indeed possible, then it is likely that Niron Magnetics has delayed by many years their use in practice, by being unable to develop such materials themselves, but simultaneously preventing others to do this.

Neodymium magnets are fascinating: they have enabled much smaller and more efficient elevator engines, used as undulators in synchroton x-ray sources, and many other places.

30 years ago the opposite was celebrated as the saviour of American capitalism (by short term thinking people who are probably billionaires now, and therefore, as individuals, insulated against any of the '30 years later' repercussions).

The US is going to need to naturalise all of its illegal immigrants to have a chance at ramping up local manufacturing.