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Author: Subject: The trouble with neodymium...
MrHomeScientist
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[*] posted on 1-3-2015 at 13:35


Correct, it's neodymium:

NdF<sub>3</sub> + 3 Li --> Nd + 3LiF
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DalisAndy
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[*] posted on 8-5-2015 at 13:11


Whats Nd reactivity compared to Cu? If not, could someone try something for me?

[Edited on 8-5-2015 by DalisAndy]
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[*] posted on 8-5-2015 at 13:14


Quote: Originally posted by MrHomeScientist  
Correct, it's neodymium:

NdF<sub>3</sub> + 3 Li --> Nd + 3LiF

The only problem I see is that NdF3 is a ionic compound. And would need to be dissolved in something, I order to react. If I'm correct
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[*] posted on 8-5-2015 at 13:25


Quote: Originally posted by DalisAndy  
Quote: Originally posted by MrHomeScientist  
Correct, it's neodymium:

NdF<sub>3</sub> + 3 Li --> Nd + 3LiF

The only problem I see is that NdF3 is a ionic compound. And would need to be dissolved in something, I order to react. If I'm correct

Not necessarily. At the temperatures being discussed, the lithium is molten, and the liquid-solid reaction interface is fine for the reaction.
Quote: Originally posted by DalisAndy  
Whats Nd reactivity compared to Cu? If not, could someone try something for me?

Neodymium is significantly more reactive than copper, I would say that it's much closer to magnesium in reactivity.




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[*] posted on 8-5-2015 at 13:32


Quote: Originally posted by gdflp  

Neodymium is significantly more reactive than copper, I would say that it's much closer to magnesium in reactivity.

So Mg could be used to precipitate Nd after decomposing the FeSO4 and separated the Boron?
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[*] posted on 8-5-2015 at 13:36


I highly doubt it. You would need a solvent that wouldn't react with the magnesium or neodymium, would dissolve and ionize both of their salts, and even then I don't think that the reaction is favorable, it would also leave a metal heavily contaminated with magnesium. You would also need the neodymium salt to be anhydrous, which is a difficult task in it's own regard.

[Edited on 5-8-2015 by gdflp]




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[*] posted on 8-5-2015 at 13:43


Quote: Originally posted by DalisAndy  
Whats Nd reactivity compared to Cu? If not, could someone try something for me?

[Edited on 8-5-2015 by DalisAndy]


DalisAndy:

ALL RE elements are very electropositive, more or less on a par with Al.

Some here (like me) believe reduction of NdF3 with Li might just about be possible. MrHomeScientist is setting things up to try that.

Otherwise it's electrolysis of anhydrous RE trichlorides (industrially).

FORGET about aqueous reductions with WHATEVER: these elements react immediately with water. They cannot be electroplated from water.

Possibly electrodeposition from deep eutectic solvents or aprotic solvents but that's firmly in the future, it at all possible even.

You need to read this long thread: no gain without pain! And people get very tired of answering the same questions over and over.


[Edited on 8-5-2015 by blogfast25]




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[*] posted on 8-5-2015 at 13:48


Quote: Originally posted by blogfast25  
Quote: Originally posted by DalisAndy  
Whats Nd reactivity compared to Cu? If not, could someone try something for me?

[Edited on 8-5-2015 by DalisAndy]


DalisAndy:

ALL RE elements are very electropositive, more or less on a par with Al.

Some here (like me) believe reduction of NdF3 with Li might just about be possible. MrHomeScientist is setting things up to try that.

Otherwise it's electrolysis of anhydrous RE trichlorides (industrially).

FORGET about aqueous reductions with WHATEVER: these elements react immediately with water. They cannot be electroplated from water.

Possibly electrodeposition from deep eutectic solvents but that's firmly in the future, it at all possible even.

How whould make NdF3? Short of using F2 gas or roach poisin
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[*] posted on 8-5-2015 at 13:58


Quote: Originally posted by DalisAndy  

How whould make NdF3? Short of using F2 gas or roach poisin

As blogfast said, read the thread. All of the information is here. You need to do some of your own homework, many methods have been discussed in this thread already.

[Edited on 5-8-2015 by gdflp]




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[*] posted on 8-5-2015 at 13:58


Quote: Originally posted by DalisAndy  
How whould make NdF3? Short of using F2 gas or roach poisin


Full preparation is in the thread.

2 NdCl3(aq) + 3 NH4HF2(aq) === > 2 NdF3(s) + 3 NH4Cl(aq) + 3 HCl(aq)

NdF3 is insoluble. Filter, dry and calcine.




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[*] posted on 8-5-2015 at 14:30


Ok thank you. A weekend of fun planned I sense. Oh I have discovered an odd occurrence. When I brought one of my hard drive magnets near the crushed motor magnet I have, when I accidently dropped it in to the motor magnet, it made the hard drive one stronger. Sticking it to its sister magnet , I can't separate them. Are there any Nd super alloys?

[Edited on 8-5-2015 by DalisAndy]
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[*] posted on 8-5-2015 at 14:54


If the magnets are 'large', separating two of them can be hard. There do exist several grades though. Composition is the same though, I think...



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[*] posted on 10-5-2015 at 11:07


Ok I just want conformation my math is correct for these reactions

Nd2Fe14B + 17CuSO4 -> 17Cu + 14FeSO4 + Nd2(SO4)3 + B

14 FeSO4 + heat -> 14FeO + 7O2 + 14SO2

Nd2(SO4)3 + 6NH3F -> 2NdF3 + 3(NH3)2SO4

then proceed with lithium replacement
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[*] posted on 10-5-2015 at 12:16


Quote: Originally posted by DalisAndy  
Ok I just want conformation my math is correct for these reactions

Nd2Fe14B + 17CuSO4 -> 17Cu + 14FeSO4 + Nd2(SO4)3 + B

14 FeSO4 + heat -> 14FeO + 7O2 + 14SO2

Nd2(SO4)3 + 6NH3F -> 2NdF3 + 3(NH3)2SO4

then proceed with lithium replacement


Copper sulphate as solvent? Hmmm... good luck with that! (It'll probably work but why waste CuSO4 on dissolving Nd magnets?)

Ferrous sulphate will oxidise to ferric oxide.

[Edited on 10-5-2015 by blogfast25]




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[*] posted on 10-5-2015 at 12:20


Quote: Originally posted by blogfast25  
Quote: Originally posted by DalisAndy  
Ok I just want conformation my math is correct for these reactions

Nd2Fe14B + 17CuSO4 -> 17Cu + 14FeSO4 + Nd2(SO4)3 + B

14 FeSO4 + heat -> 14FeO + 7O2 + 14SO2

Nd2(SO4)3 + 6NH3F -> 2NdF3 + 3(NH3)2SO4

then proceed with lithium replacement


Copper sulphate as solvent? Hmmm... good luck with that! (It'll probably work but why waste CuSO4 on dissolving Nd magnets?)

Ferrous sulphate will oxidise to ferric oxide.

[Edited on 10-5-2015 by blogfast25]

I was going to use copper sulfate because of easy of access (I'm a student and not 18 yet). But I can get sulfuric acid. also can ferric oxide be decomposed to FeO?

[Edited on 10-5-2015 by DalisAndy]
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[*] posted on 10-5-2015 at 12:24


Quote: Originally posted by DalisAndy  

I was going to use copper sulfate because of easy of acess (I'm a student and not 18 yet). But I can get sulfuric acid. Why wont copper sulfate work?


I said it would 'probably work'. HCl or H2SO4 are simply easier/cheaper. With CuSO4 you'll definitely need to grind it quite fine. Not a big problem.

Use 10 % CuSO4 than needed: this way you won't have any free Cu<sup>2+</sup> in solution, which would then have to be separated out again.

[Edited on 10-5-2015 by blogfast25]




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[*] posted on 10-5-2015 at 13:36


Quote: Originally posted by blogfast25  
Quote: Originally posted by DalisAndy  

I was going to use copper sulfate because of easy of acess (I'm a student and not 18 yet). But I can get sulfuric acid. Why wont copper sulfate work?


I said it would 'probably work'. HCl or H2SO4 are simply easier/cheaper. With CuSO4 you'll definitely need to grind it quite fine. Not a big problem.

Use 10 % CuSO4 than needed: this way you won't have any free Cu<sup>2+</sup> in solution, which would then have to be separated out again.

[Edited on 10-5-2015 by blogfast25]


And use water for the other 90%? I know Nd will react with water
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[*] posted on 10-5-2015 at 13:59


Quote: Originally posted by DalisAndy  

And use water for the other 90%? I know Nd will react with water


I meant: calculate the amount of CuSO4 needed by your equation. Then use 10 % less than the calculated value. A small amount of magnet will not react but all your CuSO4 will. This way there's no free CuSO4 in the resulting solution.




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[*] posted on 10-5-2015 at 14:49


Just thought I'd share a quick note, as I restarted my own Nd experiments: I just successfully prepared pure neodymium sulfate solution using the oxalate method.

I started with some freshly made 'magnet chloride', and added concentrated oxalic acid solution. This gave me a bright yellow precipitate, indicating iron was still present. In an attempt to start over, I ran fresh HCl through some of the precipitate while it was still in the funnel, only to encounter a curious effect: The iron oxalate dissolved away, giving an emerald green solution, but the neodymium didn't. A single wash with water gave me a pale lavender solid, which easily dissolved in a 50% mix of freshly prepared (hot) H2SO4 to yield a pinkish solution (though it looks orange in incandescent light). Right now, it's in the freezer so that the oxalic acid crystallizes out.





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[*] posted on 10-5-2015 at 15:26


ec1:


Looks like you've created a variant of the oxalate method. In my version the iron is oxidised with peroxide to ferric. With oxalate the ferric forms green and soluble trisoxalato ferrate(III), while the Nd forms insoluble Nd oxalale.

In your case you formed Fe(II)Ox and Nd oxalate. The former dissolves into dilute HCl (well known, that), the latter does not. But I'm quite surprised that Nd oxalate dissolved in hot 50 % H2SO4. RE oxalates are extremely insoluble. Interesting but requiring corroboration, I feel.

[Edited on 10-5-2015 by blogfast25]




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[*] posted on 10-5-2015 at 19:15


Quote: Originally posted by blogfast25  
ec1:


Looks like you've created a variant of the oxalate method. In my version the iron is oxidised with peroxide to ferric. With oxalate the ferric forms green and soluble trisoxalato ferrate(III), while the Nd forms insoluble Nd oxalale.

In your case you formed Fe(II)Ox and Nd oxalate. The former dissolves into dilute HCl (well known, that), the latter does not. But I'm quite surprised that Nd oxalate dissolved in hot 50 % H2SO4. RE oxalates are extremely insoluble. Interesting but requiring corroboration, I feel.

[Edited on 10-5-2015 by blogfast25]


The oxalate was freshly prepared, and had never been dried - that may have had something to do with it. I remember the first time I tried this, after calcining - nothing in Hell, Heaven or Earth could have dissolved that powder.

Fe(III), not Fe(II) - so that's what I was forgetting! I was wondering why it was so much more difficult to do now. Ah well, nothing for it but to finish off this batch and convert to NdCl3 hydrate.

What to do with all this Fe(II)-contaminated oxalic acid? Currently I have 1.5 gallons of the stuff just laying around... I suppose I should recrystallize it and put it back into its container.

Does a solution of neodymium sulfate normally look orange in artificial light and pink in natural light?




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[*] posted on 11-5-2015 at 05:16


Quote: Originally posted by elementcollector1  
[What to do with all this Fe(II)-contaminated oxalic acid? Currently I have 1.5 gallons of the stuff just laying around... I suppose I should recrystallize it and put it back into its container.

Does a solution of neodymium sulfate normally look orange in artificial light and pink in natural light?


Neutralise, so Fe(OH)2 drops out, filter. Evaporate water to get sodium or potassium oxalate (depending on base used). Quite a job on 1.5 gallons though!

Edit: it might even be easier to simply boil it down. The Fe(II)Ox should crystallise out. Remove it, then boil to dryness to obtain crude oxalic acid. It's easy to recrystallize, BTW.

Nd(III) looks different under different lighting:

http://en.wikipedia.org/wiki/Neodymium(III)_chloride

Those three 4f electrons are the cause of these colour variations.

[Edited on 11-5-2015 by blogfast25]




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[*] posted on 12-5-2015 at 10:42


Yep, some oxalic acid crystals crashed out upon cooling overnight. They look neat - sort of acicular with an odd square shape.

Anyway, as it turns out, the oxalate didn't dissolve in sulfuric acid the second time around, and something precipitated out of the first one. I think the first one was just a suspension, and had me fooled. Anyway, I now have a bright pink, wet solid - what can I use to dissolve this? Nitric acid?

So close... yet so far.




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[*] posted on 15-5-2015 at 05:43


Quote: Originally posted by DalisAndy  
Ok I just want conformation my math is correct for these reactions

Nd2Fe14B + 17CuSO4 -> 17Cu + 14FeSO4 + Nd2(SO4)3 + B

14 FeSO4 + heat -> 14FeO + 7O2 + 14SO2

Nd2(SO4)3 + 6NH3F -> 2NdF3 + 3(NH3)2SO4

then proceed with lithium replacement


Copper sulfate is an interesting idea and like blogfast said it may work, but an acid is your best bet.

I also wanted to point out / remind you that any soluble fluoride salts, like NH3F, are horrifically dangerous. They can and will kill you with a very small spill on your skin. That's not an exaggeration. Seriously not something for a beginner / young person to handle. I highly advise against that path unless you have a professional chemist to help you or a professional lab space. Have calcium gluconate on hand as a first response measure in case of spills (but still immediately go to the hospital).

An interesting alternative I investigated (briefly) is electroplating from a deep eutectic solvent (DES). Supposedly the choline chloride - urea system is capable of dissolving a wide variety of metal oxides, and being anhydrous makes it a promising candidate for plating out reactive metals. I made the DES but never tried dissolving anything in it. It's much safer, since you only need Nd-oxide, but also more speculative.


Edit:
EC1: You could calcine to decompose it to the oxide, but I'm not sure that that leaves you any better off than you are now. Possible use in the DES route?

[Edited on 5-15-2015 by MrHomeScientist]
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[*] posted on 15-5-2015 at 06:04


Quote: Originally posted by elementcollector1  
Anyway, I now have a bright pink, wet solid - what can I use to dissolve this? Nitric acid?


This has to be one of the two forms of neodymium sulphate.

Nitric acid is useless here.

Convert it to Nd(OH)3 with ammonia solution, simmer a bit to complete conversion. Then filter off and wash carefully. The pure hydroxide can then be dissolved in the acid of your choice.




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