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bur
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[*] posted on 21-6-2016 at 09:28
Radium extration


Has anyone ever tried to extract Radium?

I know the amounts are tiny, so I'm thinking of a Ra+-solution as the product. The extration to the point of a RaCl solution is not too hard:
  1. Dissolution of U ore in H2SO4 leaves Ba,Ra and some other insoluble sulfates.
  2. Most impurities are removed via NaOH and subsequent HCl.
  3. Ba impurities remain in the sludge and the (Ba,Ra)SO4 is converted to (Ba,Ra)CO3 and dissolved in HCl.

The only practical way to know if you were successful is from radiation though. As I don't have a gamma spectrometer available I'd have to rely on a Geiger counter. My problem is, there are lots of other radioactive isotopes in the ore and I'm not sure if any of them might not be extracted along the Radium. Of course their amounts are minute, but their activity isn't. So if the product is active it might be anything.

Especially the two Pb isotopes 210 and 214-Pb could end up with the Ba. I'd say separation of ng amounts of Pb from Ba might not be possible?

I thought I could add Ba at the last extraction step so I have something to precipitate. Then I'd end up with BaSO4 with a small amount of Ra incorporated.


Long story short: Will I be able to separate the Ra from the other decay products?
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DoctorOfPhilosophy
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[*] posted on 21-6-2016 at 10:09


Alexander Wimmer (a student in Austria) did exactly that, starting with uranothorianite. Supposedly his yield was 0.5 ug.

http://theodoregray.com/periodictable/Elements/088/index.s7....

Edit: to be exact, it's a small amount of RaCO3 in BaCO3. I doubt anyone has gotten past that point in recent times but it's no secret how to concentrate the radium further.

[Edited on 21-6-2016 by DoctorOfPhilosophy]
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metalresearcher
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[*] posted on 21-6-2016 at 10:57


How did you get the U metal ?
Most ebay shops don't sell radioactive elements or compounds, except K (which contains 1:8600 K-40).
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careysub
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[*] posted on 21-6-2016 at 11:33


You should consult Mme Curie's original papers on radium extraction (her PhD dissertation for example), and other radium extraction literature.

The techniques are all detailed there (but use better safety methods).

[Edited on 21-6-2016 by careysub]
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[*] posted on 21-6-2016 at 12:17


metalresearcher, he mentions U ore, which is a much better choice, because it will have all of U's daughters in equilibrium concentrations, whereas these will not be present except in minute quantities in U metal because they take a long time to grow back in (they have been removed when U was extracted from the ore).

bur, a colleague a long time ago used a method to extract small lead impurities from a barium sulphate precipitate with certain solutions but unfortunately I can't recall what he used exactly. Sorry, but at least it is possible. A quick google search suggest ammonium acetate or EDTA, but I haven't looked into it.
Pb-214 has a short half-life (around 22 minutes), so you won't have to worry about it. That is not the case for Pb-210 though.




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bur
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[*] posted on 24-6-2016 at 00:18


Thanks for your answers.

phlogiston, you're right I completely forgot about the high decay rate of Pb-214... But after having a look at the decay chain again I think it won't help. Pb-214 ends up as Pb-210 via Bi-214 and Po-214 after a few minutes. Then it takes a couple of decades to end up as stable Pb-206.

So I guess I'll just go with the simple procedure and hopefully end up with (Ba,Ra,Pb)CO3.

As was stated to extract Ra you need ore as it takes about 100 000 years until Ra equilibrium is reached. You can easily detect how much more active ore is compared to synthetic U compounds (including non-depleted). This is why mine tailings are usually more active than the extracted product.


metalresearcher, you're right metal cannot be bought easily anymore at least in the EU unless you have a license. If you're in the US however, there is at least one shop selling depleted U metal and other compounds.


This whole extraction is illegal in many countries though unless you have permission to produce radioactive substances.
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Heavy Walter
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[*] posted on 24-6-2016 at 06:03
OTC radium


Hi bur

In case you do for the fun of the extraction chemistry, go to the U ore (many mineral clubs and fairs sell small samples of different U minerals).
In case of looking the Ra for other experiments, I suggest to look at antique shops, flea markets and old clock repair shops for two items:
products from the radium quack (water "activators") and spare needles from luminous watches. (Later Ra was replaced by Tritium, so you need to measure activity).
I have been successful in both areas, even getting a kit to apply the radioactive painting!
Of course, a handy Geiger is mandatory.
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[*] posted on 24-6-2016 at 06:41


Here are some notes I took while reading Mme Curie's writings on uranium ore extraction. She of course was interested in separating all of the radioactive elements, not just radium

"Digestion of ore in concentrated sulfuric acid dissolves uranium and protactinium. For many uranium ores oxidizing conditions are needed for complete uranium dissolution. Lead, radium, polonium and actinium sulfates are insoluble.

The insoluble residue is dissolved with HCl which removes some of the polonium and actinium. Polonium can be precipitated with H2S. Actinium can be obtained after separating the solution from the sulfide residues, peroxidizing, then precipitating with ammonia.

The sulfate residue is boiled with sodium carbonate to remove all sulfates, it is then washed with water, and then dissolved in dilute HCl (sulfuric acid free). This solution contains radium, actinium and polonium. It is filtered and precipitated with sulfuric acid, which carries down barium and radium plus a little lead and actinium. The solution still contains a little actinium and polonium which can be recovered by using HCl.

The sulfate precipitate is boiled with sodium carbonate, then dissolved in HCl. Polonium is precipitated with H2S. The solution is oxidized with chlorine and precipitated with pure ammonia to remove actinium. The filtered solution is precipitated with sodium carbonate. The precipitate is washed and converted to chlorides, which are evaporate to dryness and washed with conc. HCl. Calcium chloride dissolves almost entirely, leaving barium and radium chloride, ready for fractionation."

[Edited on 24-6-2016 by careysub]
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[*] posted on 24-6-2016 at 06:45


Quote: Originally posted by Heavy Walter  
Hi bur

In case you do for the fun of the extraction chemistry, go to the U ore (many mineral clubs and fairs sell small samples of different U minerals).
In case of looking the Ra for other experiments, I suggest to look at antique shops, flea markets and old clock repair shops for two items:
products from the radium quack (water "activators") and spare needles from luminous watches. (Later Ra was replaced by Tritium, so you need to measure activity).
I have been successful in both areas, even getting a kit to apply the radioactive painting!
Of course, a handy Geiger is mandatory.


If you want to get a good quantity of ore for extraction, at a reasonable price, contact Shannon and Sons Minerals, particularly Michael Shannon himself (I can U2U his email address, I don't post anyone's personal email on a public forum). I got 2 kg of Radium King Mine uraninite (pitchblende) from him for $100 with shipping.
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[*] posted on 24-6-2016 at 06:47


Where did you find this Careysub? I've look everywhere for this! Obviously not good enough ....



Http://www.d-radlab.com/
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careysub
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[*] posted on 24-6-2016 at 07:00


Quote: Originally posted by neptunium  
Where did you find this Careysub? I've look everywhere for this! Obviously not good enough ....


What, my extraction notes above?

From reading Curie's original publications. Look up "Radioactive Substances" and "The Discovery of Radium", both are available on-line.

See also:
https://www.aip.org/history/exhibits/curie/discover.htm
for a translation of the original radium discovery publication “Sur une nouvelle substance fortement radio-active, contenue dans la pechblende,” Comptes rendus de l'Académie des Sciences, Paris, 1898 (26 December), vol. 127, pp. 1215-1217.


I have some journal articles on radium extraction that are too large to post here.

There are also old patents on radium extraction of interest.

[Edited on 24-6-2016 by careysub]
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neptunium
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[*] posted on 24-6-2016 at 07:44


Thats great ! And I read French....thanks Careysub!!



Http://www.d-radlab.com/
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bur
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[*] posted on 12-8-2016 at 07:13


careysub, thanks, that's really interesting reading.

I can also give a small update. I decided to at first extract the uranium and later recover the Ra from the sludge.

About 50 g Ore (forgot to weigh...) was crushed, 30% H2SO4 + 30% H2O2 were added, result was a greenish/yellow liquid. Addition of ammonia gave a yellow/orange precipitate. Probably mainly U + Fe. Precipitate was dissolved in HNO3. To extract the U, I added a solution of 5% TBP (tributylphosphate) in hexane. TBP is a very selective U ligand that makes a complex soluble in non-polar solvents.


Now for the first interesting result: The (UO2)(NO3)2(TBP)2/hexane solution has mild activity of about 0.2 µSv/h gamma ray measured 5 cm above surface. Beta+gamma is about 0.8 µSv/h. Background is 0.1 µSv/h. I guess this is typical natural U.

But the aquaeous phase, holding the impurities showed this: 0.3 µSv/h gamma and 3 µSv/h beta. So there's a strong beta source in there and only weak gamma. This could be Bi, Pb or Th. Pb-sulfate is not soluble. Also Bi and Pb 210/214 are both relatively strong gamma emitters. So I guess the solution holds mostly Th-234/230.

I'm trying to figure out how the beta activity should behave over the next few days. Th-234 has 24 days half-life, decaying to U-234 with a large half-life. So I should be able to detect how Th-234 decays.

What is a bit puzzling is Bismuth. It should be soluble in H2SO4 though I'm not sure how the H2O2 interferred. But if there was Bi-210/214 in there the gamma activity should be higher. But maybe I can deduce this from measuring the beta-activity over time.

Bi-214 decays with 20 mins half-life. As none of the Po-218 mother nuclide should be present it will be gone by now having decayed (via µs Po-214 alpha emitter) to Pb-210. This is a beta-emitter with 20 years half-life making it fairly low active compared to Th-234 and Bi-210.

Bi-210 has 5 days half-life decaying to Po-210, which is a relatively stable (130 days) alpha emitter.

Bottom line: Now the solution should hold the beta-emitter Th-234 and (depending on whether or not Bi was extracted) Pb-210 and Bi-210. If it's just Th-234 the decy curve should be more or less mono-exponential, otherwise I should see the 5 day half-life of Bi-210.


Does that make sense? I'll keep posting the beta/gamma activities, though unfortunately starting Monday as I'm not working on the weekend... :)
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careysub
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[*] posted on 12-8-2016 at 07:37


Great to see some one starting on this! (I will in the by and by, someday hoping to do a pre-pub on this using thorium and uranium ores).

What mineral/ore type are you starting with?

Yes, you are doing exactly the right thing to track your separations, measuring the decay (and build up) of the short-lived child nuclides and distinguishing between gamma and beta emissions.
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[*] posted on 12-8-2016 at 12:20


Very interesting, thanks for sharing.
I was considering a similar project, it is really interesting to read how you are progressing.

Do you know the approximate mineralogical composition of your ore? Are you working on 50 g as a test sample?

In my attempt to find literature on the best conditions for the sulphate to carbonate conversion step I found this thesis helpful, it may be of interest to you.
Incidentally, it has a clear picture of 60 mg of pure radium sulphate on page 18. Ofcourse, it looks rather unremarkable, but imagine the crazy amount of radiation that guy must have been dealing with to handle it.

[Edited on 12-8-2016 by phlogiston]

[Edited on 12-8-2016 by phlogiston]




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