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DJF90
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I already provided a reference to the magnesium rare-earth nitrates up thread. I guess people were just too lazy to look up the reference so I guess
I'll do the leg-work and provide the relevant pages.
In future it might be worth listening up and chasing these down for yourself. If you don't have access to these files then ask as required and I can
provide them. Ignorance won't get you very far.
The added benefit of the Inorganic Syntheses series is (much like OrgSyn), the preparations are PEER REVIEWED.
Attachment: ISv2 p29-43.pdf (1.6MB)
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Attachment: ISv2 p44-51.pdf (827kB)
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Attachment: ISv2 p52-61.pdf (1.1MB)
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Attachment: ISv2 p62-73.pdf (1.2MB)
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blogfast25
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Thanks DJF, but I cannot view these files: AR indicates there’s a ‘problem’.
Below, 1st crop, crap photo of the Nd2Mg3 double nitrate, a few gram:
The photo doesn’t really do it justice: crystals are typically a beautiful Nd lilac/violet and clear as you would expect a 24 hydrate to be.
More was synthesised this afternoon and both crops combined and are recrystallising now.
The trouble is drying them properly. After rinsing the first, still ice cold crop with a bit of iced water, I tried to get most of the water off with
filter paper, then on a low setting hot plate but they melted immediately.
The next drop will be air dried at RT on filter paper then desiccated over CaCl2.
I’ll try a melting point reading after that (melting points for all the RE2Mg3 double nitrates are listed in the paper I linked to above.
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recycle
Harmless
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I have run the elemental analysis on slurry that i have and it comes out with the following result:
wt%
Nd 19.02, Pr 5.10, Fe 50.7, B 0.73, Dy 3.23, Tb 0.02, Al 0.51, Cu 0.1, Co 1.14, Ti 0.1, Ga 0.05.
i guess there is a problem because the numbers do not add up to 100....it is possible that the slurry was not treated for the removal of water or
another lubricants that comes from cutting....
the tools are cutting only ndfeb magnets so therefore there is no traces of Sm in this slurry ......
how can i download Handbooks Patnaik Handbook inorganic chemicals 2003 ? (any help??)
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recycle
Harmless
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@ DJF90 : You have uploaded an empty pdf's...can you provide a references again please!
[Edited on 13-8-2012 by recycle]
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blogfast25
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Quote: Originally posted by recycle  |
wt%
Nd 19.02, Pr 5.10, Fe 50.7, B 0.73, Dy 3.23, Tb 0.02, Al 0.51, Cu 0.1, Co 1.14, Ti 0.1, Ga 0.05.
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So your main man is Nd. I say dissolve sludge in 37 % HCl, filter off insolubles and saturate the filtrate with K2SO4. Allow to stand overnight for
maximum yield as insoluble RE/K double sulphates precipitate.
Filter and wash filter cake with acidified sat. K2SO4. Then convert RE/K double salts with strong ammonia to RE(OH)3 + soluble K sulphate and separate
by filtration.
[Edited on 13-8-2012 by blogfast25]
[Edited on 13-8-2012 by blogfast25]
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recycle
Harmless
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blogfast25 : Thanks for nice steps  to recover Nd.... (i guess that Pr will
dissolve too ??), but HOW ABOUT Dy.....
no my main elements are Nd, Pr and Dy and i want to isolate them in a mixture....ignoring Dy and Pr is no go .....
i am aware of this paper; Journal of Alloys and Compounds; vol. 408 - 412; (2006); p. 1382 - 1385, where;
The hydrothermal treatment of used Nd-Fe-B sintered permanent magnet was investigated in order to recover the rare- earth resources efficiently.
Commercially available Ni-coated Nd2Fe14B sintered magnet was hydrothermally treated under the op- timum conditions at 110 .deg.C for 6 h in the mixed
aqueous solution of hydrochloric acid (3.0 mol/dm3) and oxalic acid (0.2 mol/ dm3). As a result, more than 99percent of Nd metal contained in the
magnet was collected as solid precipitate of Nd 2(C2O4)3*xH2O with the purity as high as 99.8percent.
The challenge is to collected all the above elements out from oxidized slurry in a particular mixture
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blogfast25
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@ recycle:
Firstly, bugger that paper: 3 M HCl (roughly 10 w%) is nothing, no wonder it takes six f*cking hours, might as well try lemon juice! 37 w% HCl is
about 12 M (mol/L), about 4 times faster. Also having oxalic acid in there risks precipitating other oxalates (most ionic oxalates are highly
insoluble), such as Fe. Their method is useless rubbish. And their claim of purity only works if the magnets contain no other REs, as the ‘method’
[cough!] does not distinguish between one and the next RE.
Hot 12 M HCl however WILL dissolve the LOT, in a matter of perhaps 2 hours tops, including ALL REs and even that bit of Ti. Insoluble residue will be
mainly a small amount of B (from NdFeB). Then precipitate all REs as potassium double sulphates, convert to mixed hydroxides. Trust me I’M NOT
IGNORING Pr, Dy: their oxides will be mixed in with the Nd (and any other RE that might be lurking there!) oxide.
Separating the REs effectively is such a specialist job I wouldn’t even begin to think about it. This mixed oxide will have commercial value,
though, make no question about it…
[Edited on 14-8-2012 by blogfast25]
[Edited on 14-8-2012 by blogfast25]
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elementcollector1
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No, it works. I've separated neodymium from iron using the oxalate method because iron formed a trioxalatoferro complex when enough oxalic acid was
added, thus staying in solution while the rare earth oxides precipitated out.
As for separating Praseodymium and Neodymium, I believe it was discussed extensively in 'the trouble with neodymium', but I don't recall if they
reached any solid conclusion.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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blogfast25
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| Quote: Originally posted by elementcollector1 | No, it works. I've separated neodymium from iron using the oxalate method because iron formed a trioxalatoferro complex [note: trisoxalato
ferric, not ferro, BF] when enough oxalic acid was added, thus staying in solution while the rare earth oxides [oxalates, not oxides,
BF] precipitated out.
As for separating Praseodymium and Neodymium, I believe it was discussed extensively in 'the trouble with neodymium', but I don't recall if they
reached any solid conclusion. |
Not only is the amount of oxalic acid discussed in that paper ridiculously small, there is also no mention of oxidising the Fe2+ to Fe3+, needed for
the separation based on trisoxalate ferric complex. Trust me, it was me who introduced that method on 'The trouble with neodymium'.
It was also me who thought I'd found some praseodymium in magnet Nd but the whole thing ended up inconclusive.
[Edited on 15-8-2012 by blogfast25]
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@ blogfast25
Look depends on the year when the magnet was manufactured. initially magnets did not have any Pr inside unless they were made for specific
applications. recently (several years ago) they have started to put some Pr in magnets in order to reduce the price.
Especially if the magnet was from hard disk drive it will be difficult to find inside any Pr. I hope this helps to explain you why there was no Pr in
your magnet.
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blogfast25
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Hmmm... the spot FOB for praseodymium appears slightly higher than for neodymium. No great savings there. Small amounts of Pr don't affect NdFeB
performance it would seem. That would be a motive to use contaminated Nd. I'm guessing here.
Also I didn't say there wasn't any Pr in my magnets (back then): I said it was inconclusive. W/o XRF it's really hard to detect small amounts of one
RE in the matrix of another.
[Edited on 18-8-2012 by blogfast25]
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watson.fawkes
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| Quote: Originally posted by blogfast25 | | Small amounts of Pr don't affect NdFeB performance it would seem. That would be a motive to use contaminated Nd. I'm guessing here.
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I would guess that it's not so much contamination as a mixed-element ore body that's being exploited, and
that the refiner is spending less money on a complete RE separation process. Cheaper cost of goods sold, adequate performance for a certain class of
product; sounds like a win overall.
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DJF90
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Sorry about that, been busy all week. It appears as if CutePDF was having a spazwank, so I've split the file using another program. Find the two
segments attached (and in working order!)
Attachment: Segment 001 of ISv2 rare earths.pdf (1.3MB)
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Attachment: Segment 002 of ISv2 rare earths.pdf (1.3MB)
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blogfast25
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Thanks DJF, these work fine.
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