Brain&Force
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Rare earth citrate production
So I'm continuing to make different rare earth citrates - I've already gotten excellent results with holmium citrate, and gadolinium citrate is
currently in progress. I do, however, have a few notes and questions regarding them.
Notes:
Both holmium and gadolinium citrate appear to be soluble in water. As I lack a balance I don't know exactly how much I'm using (bad science, I know)
but I have reason to suspect they are only soluble in excess citric acid.
If not enough citric acid is used, the metal dissolves to form a precipitate. Among the metals they all seem to have a yellow precipitate. However,
they are all at least 99.95% pure so the only source of iron possible is the file I use to powder them before reacting. Anyone know what this is? I
want to try some other acid to see if the same thing happens but I can't think of one that'll dissolve the metal cleanly and is available with
reasonable purity.
They tend to go syrupy before crystallizing, and my attempt to seed some holmium citrate doesn't seem to be working.
At the end of the day, simulating atoms doesn't beat working with the real things...
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gatosgr
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how do you make these citrates?
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Volanschemia
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By dissolving the metals in Citric Acid I would imagine...
"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and
vapor, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I were to change places with the
Persian king" - Johann Joachim Becher, 1635 to 1682.
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gatosgr
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these elements are not very reactive..
[Edited on 21-5-2015 by gatosgr]
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diddi
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LANTHANIDEZ are quite reactive. they dissolve readily in acids including citric acid. they must be stored in argon or prevent oxidation which can be
quite rapid even at low temps
Beginning construction of periodic table display
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blogfast25
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Hahahahha.
They're among the most reactive metals in the PT, matey. Quit spreading misinformation already!
Citrate buffers are used to separate the RE(III)'s by resin exchange columns. I have some juicy details for those interested.
[Edited on 21-5-2015 by blogfast25]
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Brain&Force
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Yeah, they were formed from dissolving the metal in a solution of citric acid. They actually tend to react pretty slowly compared to a metal like
magnesium, instead dissolving about as fast as zinc. I've been powdering the samples with a file - I'm a little worried about Fe contamination as
well, but it seems to be no problem.
I've actually run into a small problem with holmium - I'm finding it difficult to sand down the stringy pieces. The samarium I have is in the same
form, but is nowhere near as hard as the holmium.
Quote: Originally posted by blogfast25  |
Citrate buffers are used to separate the RE(III)'s by resin exchange columns. I have some juicy details for those interested.
[Edited on 21-5-2015 by blogfast25] |
I want to hear this
At the end of the day, simulating atoms doesn't beat working with the real things...
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blogfast25
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Dowex-50 column, elution performed at 100 C, using pH = 3.28 ammonium citrate buffer. Heavy REs elute first.
(From Glenn T. Seaborg's 'The Trans-Uranium Elements, p. 154)
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gatosgr
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I meant gadolinium and holmium compared to the other rare earths... interpretering however you like again huh?
http://www.chemistryexplained.com/elements/C-K/Gadolinium.ht...
and your juicy details
https://www.google.com.ar/patents/US2897050?
[Edited on 21-5-2015 by gatosgr]
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Brain&Force
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It seemed that you said the rare earths as a whole were unreactive. Gadolinium, dysprosium and holmium are definitely air-stable and dissolve only
slowly.
At the end of the day, simulating atoms doesn't beat working with the real things...
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blogfast25
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| Quote: Originally posted by gatosgr | | I meant gadolinium and holmium compared to the other rare earths... interpretering however you like again huh? |
Avoid txtinglish and people might know what you're on about. There won't be any interpretational problems then.
Thanks for the patent.
[Edited on 22-5-2015 by blogfast25]
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Brain&Force
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A citrate complex?
So I made some dysprosium citrate and attempted to precipitate it with sodium carbonate, to get the carbonate to precipitate. That didn't work -
instead I'm able to dissolve large amounts of sodium carbonate in the dysprosium citrate solution without any precipitate forming.
I have found a reference to a bis(citrato)lanthanum complex and I'm interested in finding out if I've made a dysprosium analog myself. But as for producing a
rare earth oxide/hydroxide/carbonate I guess I'll just attempt to pyrolyze the citrate.
At the end of the day, simulating atoms doesn't beat working with the real things...
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Brain&Force
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So I downloaded the paper and I think a buffer formed, rather than a stable citrato complex. The citrato complexes of lanthanum are only stable in
acidic solution (pH 3 at most) according to the paper I linked, and the dissolution of sodium carbonate seems to be insufficiently basic to induce
precipitation of the Dy and Ho ions.
At the end of the day, simulating atoms doesn't beat working with the real things...
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blogfast25
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| Quote: Originally posted by Brain&Force | So I made some dysprosium citrate and attempted to precipitate it with sodium carbonate, to get the carbonate to precipitate. That didn't work -
instead I'm able to dissolve large amounts of sodium carbonate in the dysprosium citrate solution without any precipitate forming.
I have found a reference to a bis(citrato)lanthanum complex and I'm interested in finding out if I've made a dysprosium analog myself. But as for producing a
rare earth oxide/hydroxide/carbonate I guess I'll just attempt to pyrolyze the citrate. |
I bet potassium oxalate would break the complex.
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