[defrost]

It's a "near monopoly" because a bunch of engineers made a plan, stuck to it, and now have vertical integration.

There's nothing preventing others from also processing concentrates (the post physical mining product).

The mining aspect is hardly monopolised either - much is sourced from Australia, South America, etc.

Put in an order, buy a 49% share of a resource company and now you're part of the action.

[HDThoreaun]

Well environmental regulations prevent companies from processing rare earths at economically competitive rates in many countries. Sure they could do it, but why would anyone pay 3x as much for “clean” rare earth when you can just get the Chinese stuff?

[defrost]

Sure, but if anybody can truck refuse and clean sewers but only one person will actually do it, that's not really a monopoly by Kenny the toilet cleaner*, that's more like a caste system with "the unclean" over there.

I'd also point out that the US has a large land area, mapped out by the USGS (below ground structures) and is capable of creating a large shallow lake area sealed off from deeper aquifers and able to be treated with neutralising agents.

On the scale of the market for global battery production the additional costs for doing it right are not punitive and arguably fall under the "national security" umbrella that see magnitude larger shovelfuls of money going to defence and traditional fossil fuel industries.

* https://www.themoviedb.org/movie/13140-kenny