Why do rare-earth permanent magnets need to be recycled instead of just reused?

Question

For years, scientists and engineers have struggled to find ways to efficiently break down and recycle rare-earth materials from various devices, especially permanent magnets....

My question is: Why do rare-earth-based permanent magnets need to be (s)melted, etc. and the elements separated again?

Aren't we still using $Ne_2Fe_14B$, the same formulation as before? As with samarium-based magnets?

Couldn't we use laser-cutting or cold-welding to reshape and/or resize them as needed? Then re-magnetize them?

Surely others must be wondering this same thing.....

Answer 1

Aren't we still using Ne2Fe14B, the same formulation as before?

There are different grades of the material.

They also corrode which is another difficulty. This is why they are plated which just replaces one challenge with another...unless you have damaged plating in which case you need to deal with both corrosion and plating.

Can you even laser cut or cold well them in the first place. Note there are other possibilities for cutting such as EDM and water jet (but corrosion...). I don't know which might work but let's assume you could for the sake of argument.

It's not practical if you have hundreds of magnets of all shapes and sizes on top of having to dealing with the aformentioned factors. Most magnet shapes aren't tessellating anyways, especially in the applications that need magnets the most.