Can old neodymium magnets be recycled?

[wmingin]

Main Question or Discussion Point

Can old neodymium magnets be crushed to a powder and re-sintered into new shapes?

 

[Simon Bridge]

Don't see why not - by some process. The real question is: "is it cost effective to do so?"

 

[Graniar]

Sure. Question is about goal and amounts.

"Crashing" has meaning if only you can't buy thin NdFeB powder.

It's not brittle enough for direct crushing.
Grinding solid magnet will consume a lot of abrasives, need in-liquid grinding or inert atmosphere to avoid burning, will complicate sintering due to a bigger fragment sizes, and product will be more porous than original.

 

[wmingin]

Thank You for responding.

With China restricting export of neodymium ore, I was wondering if recycling old magnets offered an opportunity.

Could they be melted and recast?

Regards,

Bill

 

[Graniar]

Yes, it can be melted. But I'm not sure about casting idea.

Sintering is not only about process simplification, there is some meaning to make it ceramic.
Otherwise, why they first melt this, disperse to the powder, and later sintering

How neodymium magnets are made

 

[wmingin]

Thank you Graniar.

I enjoyed the link.

By the way... I would like to know what keeps the hydrogen from igniting when

metals are smelted in a hydrogen atmosphere.

Anybody?

Thanks!

B.

 

[mfb]

Ignite with what? There is no oxygen to react with.
React with the metals? Might depend on the metals.

 

[wmingin]

How stupid of me.

I forgot that without oxygen, hydrogen won't burn.

Sorry to waste your time.

B.

 

[SredniVashtar]

Thank You for responding.
With China restricting export of neodymium ore, I was wondering if recycling old magnets offered an opportunity.
Could they be melted and recast?

There is some research done on that. Here's an example

http://www.sciencedaily.com/releases/2012/10/121024175520.htm

Scientists at the U.S. Department of Energy's (DOE) Ames Laboratory are working to more effectively remove the neodymium, a rare earth element, from the mix of other materials in a magnet. Initial results show recycled materials maintain the properties that make rare-earth magnets useful.
[more at the link]

 

[wmingin]

Very Interesting!
Thank You SredniVashtar

 

[geneiusxie]

nice. seems like this could really help out the case for electric cars.
although recycling lithium batteries might be even more important.

 

[frankygtd]

I think it does be possible.
But you can not get same strong magnet.
The property will be much weaker.

 

[frankygtd]

for old neodymium magnets, it's useful for rare earth element recovery