Gosh what an abrupt blossoming of stuff; thanks for the...

Gosh what an abrupt blossoming of stuff; thanks for the references. Quite a few items to correct and clarify.
Let’s start with “tongue in cheek”! No I don’t seriously advocate buying Fortescue or a boron mine.

Point was,on the RE front, Lynas is roughly in line with global demand for magnet manufacture in that its NdPr/DyTb ratio at 30:1 looks about right.

The claimthat I “forgot” Dy is simply untrue. (Where is the boundary between misrepresentationand blatant lying?)

The genuine argument here is how much Dy/Tb is needed to balance the NdPr to market?

I’m not sure how many children browse stuff like my previously posted ref (it is 6 yrs old): https://www.neodymiummagneti.com/magidea/ndfeb-magnets-production-process/

I note they tout that mix as used in wind turbines (33% of global usage in 2019 according to a linkin a later Chemissed post).

So what’s my reply to Chemissed’s rebuttal?

He cites a comprehensive(and excellent) review of grain boundary diffusion (GBD) as a way of thrifting HRE compared to “ordinary” NdFeB with added Dy.

Significantprogress of grain boundary diffusion process for cost-effective rare earthpermanent magnets: A review - ScienceDirect

(GBD is a bit like cement mix; the gravel can be HRE free and the HRE is in the cement.)

The displayed diagram is telling, but not in the way Chem intended.
These figures/diagrams illustrate the situation WITHOUT the use of GBD. (Check the introduction, 1^stpage 2^nd column.) So ALL the figures he quotes are using the old& obsolete method. Sloppy work! (I’d note the magnet compositions displayed in Chemissed’s later posts all share this flaw: none use GBD to reduce HRE content.)

Figure 20 on page 25summarises the HRE content for a dizzying array of GBD magnets (including some using GBD but no HRE at all.) For HRE additions the very highest coercivity (temp resilience) is for 3% Dy/Al in the mix (top middle graph). That’s a 10:1Ndy ratio for magnets at the very top of the range.

So is 10:1 the required NdPr: DyTb ratio to be in balance? Not at all for several reasons.

First, not all magnets are absolute top of range; there’s plenty of need for fridge magnets and wind turbines (for which the 30:1 blend works fine).
Second, there’s plenty of work being done on motor design and materials. GBD is certainly not the last word on magnets and improved motors lower the required operating temperatures.
For example here’s a HRE free traction motor in late-stage development that incorporates both of these strategies: https://elements-strategy.jp/en/digest/p25

In summary, can any of us say what NdPr: DyTb ratio will exactly meet the magnet market’s future needs?
I doubt it, but with the increasing number of options for HRE minimization I’m sticking with 30:1 or thereabouts. The Lynas blend.