Sciencemadness Discussion Board

Making uranium metal and thorium metal

woelen - 22-3-2007 at 01:24

Is it possible to make uranium metal from UO2(NO3)2 by means of aqueous chemistry? I was thinking of plating the metal on a copper base or something like that, but I have no idea if that is possible. Before I spend some of my precious UO2(NO3)2 on that, I first would like some advice on this.

I want this sample for my element collection. I still don't have uranium in my collection, and I hope to receive some UO2(NO3)2 next week or so. It would be great if I could isolate some of the metal.

A similar question I have for thorium. I also hope to obtain some Th(NO3)4 and I also wonder whether it is possible to plate some of this metal on a copper base.

Simply buying uranium or thorium is impossible where I live.

YT2095 - 22-3-2007 at 01:32

I believe that you reduce the nitrate to the oxide, and then use Lithium metal to reduce the Oxide to the Metal.

I`m not sure about Aqueous chem tho?


Edit: thinking about for a sec, I don`t think it is possible, these 2 metals are ~About as reactive as Calcium metal, I don`t think you`ll do it in a water based medium.


[Edited on 22-3-2007 by YT2095]

woelen - 22-3-2007 at 06:23

Is uranium really as reactive as calcium? I understood that depleted uranium is used in warfare in the head/nose of rockets for making a heavy impact.

I don't have much data on these metals, but I expected them to be less reactive, at least not such that they react with water.

YT2095 - 22-3-2007 at 06:39

it is very similar, although U is a little more reactive than Th.

if I were to compare it Chemically, then Calcium would be the closest metal that we can Identify with easily as a Comparison, Magnesium for the Th. this only my Opinion however, Cerium is very similar also.

edit: btw, although DU is indeed used in shells, they go off like a firework when they hit something, U is very pyrophoric, Th less so.


[Edited on 22-3-2007 by YT2095]

Dr. Beaker - 22-3-2007 at 09:46

Quote:
Originally posted by woelen
Is uranium really as reactive as calcium? I understood that depleted uranium is used in warfare in the head/nose of rockets for making a heavy impact.

I don't have much data on these metals, but I expected them to be less reactive, at least not such that they react with water.


1. U can even be as reactive as Fr but as long as it has an oxide/carbonate/hydroxide coating it will not react (see for an example Al and Mg).
2. If U disolves in mercury maybe you can use it to raise its reduction potential untill it is close enough to that of H3O+ at the pH you're working with (probably close to 7 since U will disolve in comon acids and also in base in believe) and then you may reduce it all the way to the metal. (the same way as you can get Na amalgam)

[Edited on 22-3-2007 by Dr. Beaker]

garage chemist - 22-3-2007 at 10:14

You may be able to reduce it to the metal using sodium borohydride in aqueous solution, or maybe dithionite.
Though you will not be able to make solid metal out of this, because the powder will burn if you heat in in the presence of oxygen. Melting would have to be done under inert gas or maybe hydrogen.
Just try it out with borohydride, I am fairly sure it will work.

In order to get solid U metal, a thermite reaction would probably be best. Roast your uranyl nitrate until you have UO2, then reduce with Al or if that isnt reactive enough, Mg. Under protective gas of course.

[Edited on 22-3-2007 by garage chemist]

unionised - 22-3-2007 at 11:47

IIRC Uranium borohydride is a fairly well characterised material so I don't see this reaction working.

The_Davster - 22-3-2007 at 15:58

I have to say, I would scared shitless to do any thermite type reaction involving uranium compounds, too much becomes airborne. And even when done under an inert atmosphere you are left with what? A mix of uranium(potentially finely divided) and Al2O3 further processing to remove Al2O3 would be annoying and of course further complicated by uranium's reactivity.

There are documents in the LANL archives on this site which detail the electrochemical methods of producing either U or Th, I forget which.

I know Uranium can be made from the thermal decomposition of the oxalate, but again there is the problem with it being finely divided after.

As one who has worked with uranium, and perhaps impacted my future lifespan as a result of potentially inhaling a little oxide from a piece that caught fire, all I can say is take the utmost precautions to keep anything from being airborne.

Uranium seems a bit less reactive than calcium in my experience, perhaps along the lines of vanadium? Any reaction with water is very slow.

not_important - 22-3-2007 at 16:58

As I never have seen a reference to production of either U or Th metal in an aqueous environment, I rather doubt it can be done. I would think that if it were practical that route would have been used at some point instead of the more extreme methods that were.

The first production of uranium metal used the anhydrous chloride and potassium; later sodium replaced potassium, calcium is also used. I remember reading that zinc will displace uranium from a melt of mixed U/K/other chlorides.

The van Arkel–de Boer method can be used to produce either metal in good purity and in a crystalline form.

The general subject was discussed here http://www.sciencemadness.org/talk/viewthread.php?tid=6714&a...

Ozone - 22-3-2007 at 18:21

Be aware though, that any chemical manipulation to produce U of Th metal will yield a very fine suspension...and that very fine U or Th are both pyrophoric. There will need to be provisions to handle (chemistry and metallurgy) these metals under an inert atmosphere.

Cheers,

O3

woelen - 22-3-2007 at 23:13

Thanks for all your reactions. I probably have to conclude that making the metal from these salts is beyond my reach. I hoped for some suggestion with aqueous chemistry (something along the line of plating nickel from a nickel (II) + hypophosphite solution), but apparently that is not possible for U and Th.

I am also very scared for inhaling finely divided U-dust or Th-dust, so thermite & Co are not an option to me. Maybe the decomposition of the oxalate. I have experience with that reaction with FeC2O4, but the material is VERY air sensitive. With iron, the material became brown in seconds when air was allowed to enter the fine black powder. I can imagine that U and Th even ignite under such conditions :(.

Well, if I get the salts, then at least I have some nice new reagents (uranyl salts are quite interesting on their own), and I'll have to look further for solid lumps of U and Th.

not_important - 23-3-2007 at 01:26

I suspect that the oxalate will give you an oxide.

Attachment: The Thermal Decomposition of Thorium Oxalate.pdf (980kB)
This file has been downloaded 681 times

Dr. Beaker - 23-3-2007 at 05:37

maybe a (controled) thermolysis of the azide?
I know NaN3 decompose to Na metal and dinitrogen, so maybe the U azide can also?
though I suspect you'll 1st have to reduce it to the III ox. state.


[Edited on 23-3-2007 by Dr. Beaker]

woelen - 9-4-2007 at 10:59

I just received the uranyl nitrate and thorium nitrate. The uranyl nitrate looks amazing.

http://woelen.scheikunde.net/science/chem/compounds/uranyl_n...

You can SEE that it is poisonous, something with such a color cannot be good for you :D.

Based on all of your responses, I will not attempt to make the metal, it sounds too dangerous for me. I'll do some nice experiments though and in due time a webpage on uranium aqueous chemistry will follow.

Elawr - 9-4-2007 at 16:45

AWESOME looking picture, woelen. I agree, your uranyl nitrate is definitely wicked-looking. Is the salt luminous, that is able to glow in the dark without being excited by uv light?

Are you a boy scout? ;)

woelen - 10-4-2007 at 04:53

The salt is pale yellow, when viewed in dim light (e.g. tungsten light). As soon as it is viewed in daylight, but also when a TL-lamp is used, it has this beautiful weird glow. In the dark, however, the solid does not glow. It only converts short wavelength light to green/yellow light, but it does not store energy.

[Edited on 10-4-07 by woelen]

Waffles - 16-4-2007 at 08:18

If anyone is interested in the chemistry discussed in this thread, I have lots of Th nitrate and oxide as well as U nitrate and sulfate (and maybe oxide as well, I forget) to get rid of. U2U me, though I probably won't respond to anyone who doesn't have at least a minor history on this forum.

unionised - 16-4-2007 at 10:13

What country are you in? It's not the sort of thing I'd like to send through customs.

Waffles - 16-4-2007 at 14:51

Quote:
Originally posted by unionised
What country are you in? It's not the sort of thing I'd like to send through customs.


I've actually shipped stuff across borders (across your border, to be specific, since I'm not in your country) and never had any problems. Of course, everything leaves in a secure, padded container with plenty of lead.

Chemophiliac - 2-6-2007 at 06:27

Anyone know anything about the complexing of uranium and thorium compounds? When it comes to rare earths, I have difficulty predicting their coordinating behavior. I know that U has all different kinds of crazy coordination numbers but what are the most common? Also, I don't know where to obtain uranyl nitrate or sulfate but both are VERY interesting compounds, even just for a compound/element collection! I have a decent sized collection of radioactive minerals as an annex of my main collection and a lot of the U secondary minerals (like autunite and andersonite) are HIGHLY fluorescent under both short and longwave UV light.

Chemophiliac - 2-6-2007 at 06:28

Oh yeah, I'm just wondering about REE complexing in general. This is where one of my greatest interest lies but I don't know really anything about it. What are the basics behind it? When you involve more electrons, I suspect the complexing behavior is a lot more complicated.

woelen - 2-6-2007 at 10:41

Due to the larger central atom size, the coordination number of most REE complexes is more than that of the first row transition metals. E.g. where most first row transition metals have aqua complexes of coordination number 6, those of the REE are 8, 9 or even higher.

The coordination chemistry of REE is less impressive than that of the transition metals. Where I can obtain a lot of colored and peculiar complexes with the transition metals, I hardly find any complexes with the REE, at least not in aqueous solution.

In the meantime I did quite some experimenting with uranyl nitrate as well. The uranyl ion is a surprisingly weak oxidizer, and also the number of coordination complexes is not that high. The only really surprising complex is that with hexacyanoferrate (II), a beautiful brick/red compound.
Uranyl can be reduced with zinc powder in dilute acid, giving a green solution of uranium(IV), but this is not a very spectacular change. The yellow/green fluorescent color of the uranyl ion is not that far away from the green color of U(IV).