Dangle89
Harmless
Posts: 42
Registered: 28-7-2015
Member Is Offline
Mood: No Mood
|
|
NdF3 to... anything?
Hello everyone 
I got a heap of NdF3 (wet and unknown purity) off a mate and fellow SM member the other day  Was grabbing a bunch of other rare earth salts to play / experiment with and he chucked the NdF3 in for next to
nothing so couldn't say no!
Was researching any possible reactions for this and couldn't really find anything!
The only 2 things I saw about it was a SM thread where someone asked if there were any solvents to dissolve it and another website saying that a
thermite reaction with Mg would produce Nd metal (reference below).
http://thehomescientist.blogspot.com.au/2011/08/neodymium-me...
Just wondering if anyone knows any other reactions I could do to this stuff to turn it into another Nd compound that is easier to do reactions with?
Saw that NdF3 is incompatible with Acids, as it forms HF, so hoping to keep away from those reactions if possible as I poo myself just a little when I
think bout HF fumes
Anyone got any ideas or know if reactions with basic solutions might work ?
Cheers everyone
Dangle
|
|
|
j_sum1
Administrator
Posts: 6229
Registered: 4-10-2014
Location: Unmoved
Member Is Offline
Mood: Organised
|
|
You need to read the thread, "the trouble with neodymium"
http://www.sciencemadness.org/talk/viewthread.php?tid=14145
Short answer, get some lithium, design a novel reaction vessel and join the fun.
|
|
|
Dangle89
Harmless
Posts: 42
Registered: 28-7-2015
Member Is Offline
Mood: No Mood
|
|
Wow! Massively long thread!
Will read through it now but just to clarify, looking to convert it to another (easier to turn into different compounds) salt rather than the metal.
I have 100+g of the stuff so turning it all to metal would use a LOT of Li or Mg!
If going to Nd metal and then to a different salt in acid is the only way will do that but hoping not to use probably 50-100 dollars worth of
materials only to drop it in acid again 5 mins later 
Thanks for the link though Will read through it all now!
Dan
|
|
|
j_sum1
Administrator
Posts: 6229
Registered: 4-10-2014
Location: Unmoved
Member Is Offline
Mood: Organised
|
|
If you can find a fluoride with a significantly different solubility from a Nd salt then you should be able to pull something out with a precipitation
reaction. I offer this as a start:
https://en.wikipedia.org/wiki/Solubility_table#N
However, woelen is on first name terms with all kinds of intriguing inorganic compounds and if he chimes in here I would trust his comments
completely. Likewise blogfast has extensive knowledge of solubilities and thermodynamic data and if he says an idea won't float, he is usually right.
Watch out for both posters in the thread you read.
|
|
|
Dangle89
Harmless
Posts: 42
Registered: 28-7-2015
Member Is Offline
Mood: No Mood
|
|
Yeah, I was hoping if I put some in a NaOH or NH4OH solution that I would end up with something along the lines of:
NdF3(s) + 3NaOH(aq) = Nd(OH)3(s) + 3NaF(aq)
OR
NdF3(s) + 3NH4OH(aq) = Nd(OH)3(s) + 3NH4F(aq)
I like the NaOH idea better as the NH4OH could possibly(?) make NH4HF2 and NH4HF2 + H2O makes HF 
As stated before I want to try and keep away from HF as much as possible because, knowing my luck, I would spill it on myself and die!
Yeah hoping blogfast joins in! Some of the things he was talking about in the other thread you directed me to are WAY over my head!
Only stuff I have really seen from woelen is in the Detritus section Hehehe
some of that stuff is good for a laugh
Thanks again!
[Edited on 11-8-2015 by Dangle89]
|
|
|
MrHomeScientist
International Hazard
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
The website you linked is mine, and that procedure is actually very outdated. I should probably revise or take down that post altogether. The large
thread here details our experiments along these lines, and yes it is very long but very full of excellent information.
The driving factor in your two equations is whether the hydroxide is less soluble than the fluoride. If not (and I don't believe it is), that reaction
won't proceed at standard conditions. You might be 'stuck' at the fluoride because it's so insoluble. I would be happy to take it off your hands as
feedstock for my experiments toward reducing it to the metal If I ever get back
to that one, that is. Every weekend I say I'm going to work on it, but other things always come up.
Other differences in my blog post is that Mg won't work for us (Li is required instead), and fully separating out the iron is much more involved and
involves the use of a potassium sulfate double salt. Grab a bag of popcorn and have fun reading the thread! Most of my posts where actual
experimenting is done have pictures, if you want to skim a bit.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
One way of converting the NdF<sub>3</sub> is with potassium oxalate. The RE oxalates (including the Nd one) are hugely insoluble, much
more so than than the fluorides, so that displacement reaction should work well.
So soaking your NdF<sub>3</sub> in strong, hot K oxalate for some time will convert it to Nd oxalate. After filtering and careful washing,
dry it and calcine it in the presence of air to obtain Nd<sub>2</sub>O<sub>3</sub>. The latter can be converted to sulphate
with hot, strong H<sub>2</sub>SO<sub>4</sub>.
Treating NdF<sub>3</sub> with conc. H<sub>2</sub>SO<sub>4</sub> will also displace the HF because it is volatile.
But dealing with gaseous HF is not something I'd recommend to hobbyists!
[Edited on 11-8-2015 by blogfast25]
|
|
|
Dangle89
Harmless
Posts: 42
Registered: 28-7-2015
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by blogfast25  | One way of converting the NdF<sub>3</sub> is with potassium oxalate. The RE oxalates (including the Nd one) are hugely insoluble, much
more so than than the fluorides, so that displacement reaction should work well.
So soaking your NdF<sub>3</sub> in strong, hot K oxalate for some time will convert it to Nd oxalate. After filtering and careful washing,
dry it and calcine it in the presence of air to obtain Nd<sub>2</sub>O<sub>3</sub>. The latter can be converted to sulphate
with hot, strong H<sub>2</sub>SO<sub>4</sub>.
Treating NdF<sub>3</sub> with conc. H<sub>2</sub>SO<sub>4</sub> will also displace the HF because it is volatile.
But dealing with gaseous HF is not something I'd recommend to hobbyists!
[Edited on 11-8-2015 by blogfast25] |
Yay!!! This is exactly the kind of thing I was looking for! Also just bought 500g of Oxalic acid the other day
Will make a concentrated solution of K2C2O4 based on:
H2C2O4 + 2 KOH = 2 H2O + K2C2O4
Just wondering if you have ever done / have any info for this reaction?
I'm guessing the formula would be:
3 K2C2O4 + 2 NdF3 = 6 KF + Nd2(C2O4)3
But just wanted to check what the "soak for some time" meant i.e. Hours, days,
weeks.
Thank you so much as HF fumes are something I don't want to mess with anytime soon!
MrHomeScientist - I can take that link away if you like
Also don't worry I do intend on using some to make Nd metal Just as the NdF3
is of unknown (as a rule of thumb I always assume "unknown" is low grade) purity didn't want to waste a bunch of Li to end up with crap!
Thanks again and if any more ideas or more info on the K2C2O4 method come to anyone, Please feel free to post any thoughts
Dan
|
|
|
Dangle89
Harmless
Posts: 42
Registered: 28-7-2015
Member Is Offline
Mood: No Mood
|
|
Sorry, also one other thing, how would you recommend disposal of the KF solution? Would be happy to boil it down and keep the solid but seeing as I
cant use a glass beaker I don't think that is an option
Also don't want to just leave something like that lying around to evaporate as someone will probably get drunk in the back yard and drink it!
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
@Dangle89:
Yes, your reaction equation is correct. Note that your liquor will now contain dissolved KF and water soluble fluorides are toxic, so take precautions
and dispose of safely.
I've never done this myself and would do it as follows:
1. Make sure you use an excess of K oxalate, at least 50 % on the stoichiometric amount.
2. Use saturated (or near-) K oxalate solution.
3. Keep mixture at near BP for at least an hour, stirring constantly if possible. Cool and stand overnight. Use a PP beaker, as fluorides attack
glass.
4. Decant off supernatant and dispose of safely.
5. Filter off Nd oxalate and wash profusely with plenty hot water, then plenty cold. You need to really remove all soluble fluorides to be safe.
6. Dry and fire the oxalate to the oxide. You'll need 500 + C for that.
[Edited on 11-8-2015 by blogfast25]
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Dangle89 | Sorry, also one other thing, how would you recommend disposal of the KF solution? Would be happy to boil it down and keep the solid but seeing as I
cant use a glass beaker I don't think that is an option
Also don't want to just leave something like that lying around to evaporate as someone will probably get drunk in the back yard and drink it! |
The absolutely safest way is to add conc. CaCl2 solution to it, until nothing precipitates any more. The amount needed can easily be calculated from
the amount of K oxalate used.
Residual oxalate will precipitate as Ca oxalate, fluorides as CaF2. Allow to stand to decant off. The supernatant liquor can then be disposed of in a
sink. The precipitates can go with non-recyclable household waste.
[Edited on 11-8-2015 by blogfast25]
|
|
|
FriedBrain
Harmless
Posts: 14
Registered: 10-8-2015
Location: Germany
Member Is Offline
Mood: No Mood
|
|
For disposal of the soluble fluoride ions I would recommend to treat the solution with an excess of a solution of Calciumchloride or any other
soluble Calcium salt. This will precipitate all the fluoride as harmless Calciumfluoride. You can filter this and wash it with hot water, and there
you also have some pure Calciumfluoride
Edit: Oh, someone was a little faster then me. But yes, I forget there should be some excess oxalate in solution which would precipitate as
Calciumoxalate
[Edited on 11-8-2015 by FriedBrain]
You always have time to do some chemistry, but maybe you just have other priorities?
|
|
|
MrHomeScientist
International Hazard
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
Cool that we've got another person interested in making Nd metal. Hopefully you have more patience and a willingness to learn than the last guy. The
good news is having the fluoride already has saved you a mountain of work.
The last step isn't trivial, though. The reduction
NdF<sub>3</sub> + 3Li --> 3LiF + Nd
must be done under inert atmosphere, and requires quite a bit of heat to get started. So you'll need an argon source (or similar) and an inert
atmosphere crucible. I bought the former and made the latter.
Personally I'm hoping melting the Li will be enough to get things going, then the exotherm takes it the rest of the way. The chances of that being the
only heat I need to apply are, I think, pretty slim but we'll see.
|
|
|
j_sum1
Administrator
Posts: 6229
Registered: 4-10-2014
Location: Unmoved
Member Is Offline
Mood: Organised
|
|
| Quote: Originally posted by MrHomeScientist | | The website you linked is mine, and that procedure is actually very outdated. I should probably revise or take down that post altogether. The large
thread here details our experiments along these lines, and yes it is very long but very full of excellent information. |
@MHS
I just re-read your blog on this. Granted, a lot has been learned since your initial posts but the bulk of your procedure is sound. I wouldn't
remove it. And you already have an addendum that notes Li is needed and not Mg. Maybe just a summary of the other routes that you have been
investigating.
I confess that I dipped out of this race early on. I just figured that it was going to be a bit beyond me at this stage. It is on the "thing I might
get to one day" list. And likely I will be working with Lanthanum. LaCl3 is relatively easy for me to obtain. In what purity?? well, that remains
to be seen.
Back on topic, anything that is posted on Rare Earths and their various chemistries is useful. Any backyard process with these is going to be a
finickity thing and a good rounded knowledge base is essential.
|
|
|
Dan Vizine
National Hazard
Posts: 628
Registered: 4-4-2014
Location: Tonawanda, New York
Member Is Offline
Mood: High Resistance
|
|
I hate to be the one shooting ideas down, but the molten alkali/alkaline metal reductions require a certain outlay of money or some incredible luck in
procurement. You need a tank of high grade inert gas, a regulator, means to utterly seal the reactor during the reaction, a way to handle the reduced
metal recovery, a reactor which won't contaminate the metal. Isolation of impure materials may be doable, but without lab grade equipment, you're not
likely to achieve pure materials. And, the temperature of molten lithium is far too low to achieve most salt reductions of transition metals and
above.
The good news is harder to come by. The occasional steals available on sites like eBay are just about essential. You are not going to get anywhere
with $50. When you chase the lanthanides, you're in serious company.
[Edited on 12-8-2015 by Dan Vizine]
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
Deserve"...F. Zappa
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
I even have doubts about blogfast's method with oxalate. I do not say that it does not work, but given the low solubility of NdF3 I expect the
reaction to be very slow, maybe so slow that it is useless. You first should give it a try with a small amount in a test tube, before you spoil a lot
of chemicals. Another complication is that it will be hard to see when the reaction has completed. There is the risk of partial reaction in which the
particles become covered by a thin layer of Nd-oxalate, which prevents further reaction.
The only sure method is dissolving the NdF3 in hot conc. H2SO4, so that HF can escape and Nd2(SO4)3 remains behind. You need a non-glass
heat-resistant container if you want to do this (lead "beaker" will do, you could construct one yourself from lead, used in construction work)
|
|
|
Dangle89
Harmless
Posts: 42
Registered: 28-7-2015
Member Is Offline
Mood: No Mood
|
|
Hello again
Cheers for the input (Sorry had that written as impurity for ages!) everyone!
Hmmm... Hi temp in a high purity inert atmosphere is just a tad beyond my current set up Will hold on to some of (by the sound of thing in this thread, possibly most of!) the NdF3 to attempt the Nd metal a later date
Will start with small quantity's for the K2C2O4 method as woelen suggested and have my fingers crossed it works!
Figured I might as well get a PTFE beaker to try this in as one day I will work up the skills / courage to start attempting to work with F compounds
and wouldn't hurt to have some of the equipment on hand
Does anyone know a good cheapish source for PTFE equipment? Had a look online and prices range from $15 (Chinese ebay) to about $100 for a 250ml
beaker!
Happy to pay more than $15 as I don't like the idea of putting my life in the hands of a possibly useless backyard made beaker
Not sure why F compounds scare me so much as I am happy to handle other toxic elements / compounds (Hg, Tl, As, U). Probably just a mental thing but
figure it is better being scared and careful than overconfident and dead
Thanks so much again everyone
Hope to hear from you all again soon!
Dan
[Edited on 12-8-2015 by Dangle89]
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Dan Vizine | I hate to be the one shooting ideas down, but the molten alkali/alkaline metal reductions require a certain outlay of money or some incredible luck in
procurement. You need a tank of high grade inert gas, a regulator, means to utterly seal the reactor during the reaction, a way to handle the reduced
metal recovery, a reactor which won't contaminate the metal. Isolation of impure materials may be doable, but without lab grade equipment, you're not
likely to achieve pure materials. And, the temperature of molten lithium is far too low to achieve most salt reductions of transition metals and
above.
|
MrHS has a quite simple set up that involves an inert blanket and heating to about 600 - 700 C of the reagent mixture, for the preparation of small
amounts of Nd by reduction of the fluoride with Li (we know that the reaction is exothermic by about - 200 kJ/mol, IIRW). The set up is described in
the thread linked to higher up.
While I doubt high purity Nd can be obtained with it, that's not really the purpose of the idea.
Wait and see, I guess...
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by woelen |
The only sure method is dissolving the NdF3 in hot conc. H2SO4, so that HF can escape and Nd2(SO4)3 remains behind. You need a non-glass
heat-resistant container if you want to do this (lead "beaker" will do, you could construct one yourself from lead, used in construction work)
|
Would you yourself care to do this on anything other than the smallest of scales? Without scrubbing out the HF?
Yes, lead retorts have been reported for this. Lead melts at 328 C so good temperature control is essential.
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
I would feel confident to do this on a small scale outside on a breezy day. E.g. take 10 ml of H2SO4, add 3 grams of NdF3 and put all of this in a
small lead "dish", made from construction lead by curving it, so that a dish is formed. This dish can be put on a layer of dry sand, which is put in a
pan on a heater. The heater must be put outside, using an extension cord for power and then keep a distance of several meters.
Of course, you must have at least a decent garden, and be sure that neighbours are not exposed.
[Edited on 12-8-15 by woelen]
|
|
|
unionised
International Hazard
Posts: 5103
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
Just a thought; if I remember rightly, the carbonate is very insoluble so boiling with sodium carbonate solution might convert the NdF3 to Nd2(CO3)3
(and sodium fluoride).
Since the fluoride isn't converted to a volatile form, it might be slightly safer than the Sulphuric acid idea.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
