Talk:Uranium trioxide/Archive 2

From Wikipedia, the free encyclopedia

Archive This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.
← Archive 1 |
Archive 2
| Archive 3 →


Contents

Combustion or sublimation

Sublimation

Wilson and Ackerman never state any combustion products because they have done no combustion. So citing them for combustion is not OK. The Ackerman is only researching Oxides in general and the transformation. They state that there is no UO3 vapor present due to the calculations mentioned above. Sublimation from UO3 nor from U3O8 will ever occure at temperatures below 500°C which is OK with the calculations for the partial pressur of UO3.

What evidence is there that Wilson did no combustion? How do you do a high-pressure, high-temperature investigation of the uranium-oxygen system yeilding emperical data without burning uranium? --James S. 06:36, 29 March 2006 (UTC)
Abstract--An investigation was made of the effects of combined ultrahigh pressure and high temperature on the oxides of uranium with particular emphasis on U3O8. This is the first line of the artikel so this is Uraniumoxide no Uranium article. The word combustion ore uranium is not in the text.--Stone 07:51, 29 March 2006 (UTC)
How do you explain, then, the UO3 observed by Salbu et al. (2005), and the statement of Cotton (1991), that aerial oxidation of any uranium compound forms uranyl compounds? --James S. 08:42, 29 March 2006 (UTC)
Without resaearch papers nobody should explain Uranium combustion! Suggestions: UO3 is formed by condensation, and bevor the O2 loos apears the temperature is down to 500°C where U03 is metastable and there it is. Or Some U(VI) compound gets hydrolysed ofter the fire, or something else. This is not the point of disscussion for me I think. I always was OK with the statment that solid UO3 is found in the combustion products. Its not a major product but some saw it and this is OK, the point is the gas and this will be my point for ever!--Stone 09:00, 29 March 2006 (UTC)
Do you think that Professor Simon Cotton, one of the foremost experts on actinide chemistry, agrees with your opinion? Can you cite a single peer-reviewed scientific or medical paper which agrees with your opinion? --James S. 10:11, 29 March 2006 (UTC)
As long there is no combustion experiment done with uranium its easy to state something like "Aerial oxidation of any uranium compound eventually results in the formation of a uranyl compound." Not stating which one and where they come from eventually.--Stone 10:40, 29 March 2006 (UTC)

You said someone should claim Ackemann wrong! He is right! He does chemical transport reaction from U3O8 nothing more and nothing less. Wilson is also right for Uraniumoxide interconversion. But they all give low vapour pressure for the oxide.

So? As mentioned, lampblack carbon has a low vapor pressure, but carbon soot is a common combustion product. --James S. 06:36, 29 March 2006 (UTC)
Yes! Its a solid formed at the border of the flame! There is no carbon soot gas flying around for weeks forming carbon soot in your lungs. The soot condenses at the boarder of the flame to particles of different siece, because the vapour pressure of carbon is low and condensation the only way to go.--Stone 06:52, 29 March 2006 (UTC)
So, you admit that vapor pressure has nothing to do with combustion product formation, do you not? --James S. 08:42, 29 March 2006 (UTC)
If you admit that the folowing step of condensation has nothing to do with the combustion!--Stone 09:02, 29 March 2006 (UTC)
What? I don't know whether I can parse that sentence. --James S.

The condensation of the product is described by the gas law and the mass law. The calculationes done from me and others indicate that at standart conditions no UO3 gas is present. So why mention it at all. This is the poinz of the whole thing molecular UO3 is not woth mentioning! Because the vapour pressure of it is so close to zero that even if you assume its toxic nobody will ever take up more than a few molecules. So if you state that condensation is nearly 100% with only a few molecules in gasphase the whole UO3 mythe (flying around for weeks and gasous UO3 major product of combustion) can go!--Stone 10:05, 29 March 2006 (UTC)

Your edits show that you do not understand the proportions involved. --James S. 10:11, 29 March 2006 (UTC)
Than give the proportions which are necessary to understand the thing! Is there 1g/m3 or 1kg/m3 or like I suggest no atom/m3.--Stone 10:35, 29 March 2006 (UTC)

Combustion

There is no statement that U03 is formed as main combustion product. Ackerman, Willson, Chatillon, Nakajma, Capone, Capone, Arai, Guido all start from different oxides and so the sublimation or transport reaction mentioned for the Ackermann paper fit to the problem and again we get nothing else as no UO3 vapor present due to the calculations mentioned above. Sublimation from UO3 nor from U3O8 will ever occure at temperatures below 500°C which is OK.

To give back the compliment you made: The rest is shown as object fraud, because your plasma burning uranium oxide is a nice try but the exact paper giving the plasma burning experiment of uranium and the composition of the gas phase is no where given. So who is doing the object fraud?

If you mean, "abject fraud," these unsigned and semi-grammatical comments suggest their author is. --James S. 06:36, 29 March 2006 (UTC)
You accused persons trying to state that sublimation has the same mas laws with this nice phrase James, read your own coments bevor posting!--Stone 06:54, 29 March 2006 (UTC)
On the contrary, I accused you of ignoring the explanation of Cotton (1991) and the emperical evidence of Salbu et al. (2005). --James S. 08:42, 29 March 2006 (UTC)
Look at the archived page under the OK headline!--Stone 07:21, 29 March 2006 (UTC)
To what in particular do you refer? --James S. 08:42, 29 March 2006 (UTC)
You have shown no evidence to the contrary, and your attempts to use sublimation proportions to represent combustion product formation are easily shown as abject fraud. --James S. 17:52, 24 March 2006 (UTC) To accuse others of FRAUDE is not nice at best!--Stone 09:04, 29 March 2006 (UTC)
I said that your attempts to use sublimation could easily be shown to be abject fraud, not that you were intentionally committing fraud. Do you understand the difference? --James S. 10:23, 29 March 2006 (UTC)

Back to the point:To give back the compliment you made: The rest is shown as object fraud, because your plasma burning uranium oxide is a nice try but the exact paper giving the plasma burning experiment of uranium and the composition of the gas phase is no where given.--Stone 09:04, 29 March 2006 (UTC)

Again, you ignore Cotton (1991), and you have no sources at all which claim that uranyl compounds are not always the result of oxidation of uranium compounds in air. Therefore, your edits are easily shown to be abject fraud, whether you intend them to be such or not. --James S. 10:23, 29 March 2006 (UTC)

Another point why should be the most exothermic product be the one favoured at high temperatures? My chemistry knowledge says: high temperatures favour the less exothermic or endothermic reactions. Example: Burning coal: (Boudouard-Equilibrium)

Carbondioxide is the more exothermic one and is formed at low temperatures (394kJ/mol).
Carbonmonoxide is the less exothermic one and is formed at high temperatures (110kJ/mol).

400°C 99/1 600°C 77/23 800°C 10/90 1000°C 1/99

With this numbers UO would be the main compustionproduct.

Except it is endothermic, and unstable, and oxygen deficient. What do the thermodynamics tell you UO + O2 is going to be? --James S. 06:36, 29 March 2006 (UTC)
The whole point is that if you put energy into a system edothermic reactions take place. Simply take a chlorine molecule. Heat it and it starts to break into atoms. This reaction is endothermic as well. The reaction of forming C0 from CO2 is also endothermic and it works because you give the needed energy to the system by heating!--Stone 07:20, 29 March 2006 (UTC)
You are avoiding the fact that UO is seriously oxygen defecient, and is much more likely to absorb an entire O2 than another single oxygen, given the relative enthalpies of formation. Your edits show only subterfuge in avoiding the basic thermodynamic math involved, and not an understanding of the processes. --James S. 08:42, 29 March 2006 (UTC)
Its not possible to create substances wich are endothermic? You are not understanding the processes--Stone 09:19, 29 March 2006 (UTC)

So where is the literature indicating that this law of reactions is not true for the uranium oxides.

Where do you proposed that the 75% U3O8 of the solid combustion product comes from, if not UO3? --171.66.111.77 03:18, 29 March 2006 (UTC)
UO has a uptake of O2 or UO3 is formed as solide and than loses O2 or something else. If no literature is shown for combustion products the whole discussion is handwafing and should go to the rubish! There is no literature for high temperature compustionproducts of uranium at least I found only the burning temperatures which do not state any components.--Stone 06:16, 29 March 2006 (UTC)
Do you believe, then, that the UO3(g) condensation to U3O8(s) equations in Wilson (1961) are inconsistent with the observations of Salbu et al. (2005)? --James S. 06:36, 29 March 2006 (UTC)
The loos of O2 from UO3 or the uptake of O2 by U3O8 or what ever other reaction can form U3O8. The Salbu hase no clear evidence for UO3 as he states it himself. ´Nobody ever stated exact conditions to get UO3 at high temperatures in a flame so this are at bes assumptions without citable literature.--Stone 06:49, 29 March 2006 (UTC)
Brit Salbu is female, and she and her coauthors very explicitly state that UO3 inhalation should be expected given her spectroscopic data. Why do you misrepresent the text? Do you think everyone else can't read the plain language? --James S. 08:42, 29 March 2006 (UTC)
She says although the fit to UO3 literature XRDdata suffers from uncertainties (Fig. 4c) this is a weak statment for inclusion in a enzycolpedia.--Stone 09:19, 29 March 2006 (UTC)

Combustion vs. sublimation

Stating that the uranium trioxide reacts different if it is created by plasma or sublimation simply shows a lack of chemical knowledge and is a point no chemist will ever accept.

Counterexamples exist. --James S. 06:36, 29 March 2006 (UTC)
State it! And I will look at it!--Stone 07:15, 29 March 2006 (UTC)
Simon Cotton, perhaps the world's foremost expert on heavy metal chemistry, states that uranyl compounds are the result of aerial oxidation of any uranium compounds. Do you have any reasons that Professor Cotton is mistaken? In any case, your universal quantification that "no chemist will ever accept" these plain facts is shown quite false, and your persistence in making such false remarks shows the intellectual bankruptcy of your position. --James S. 08:42, 29 March 2006 (UTC)

Born Haber cycle is easy to understand and as simple as going up 2 flours with elevator and than 7 by the stairs or rocket up to the 12 flour and than 3 down with the fire ladder you end up in the same flour.

Everything else would give nosense. So first oxidising than sublimation than condensation makes no difference to sublimation of uranium than oxidation and than condensation.

I do not understand this. Combustion is not sublimation. --James S. 06:36, 29 March 2006 (UTC)
But the laws for the folowing condensation apply to bot reactions products. It does not matter if you creat the UO3 molecules by combustion, plasma reaction, sublimation from UO3, or simple wichcraft. They have to follow the laws of physics. The laws of physics are no dont's they are cant's. (impossible to violate!)--Stone 06:57, 29 March 2006 (UTC)
What is your native language? I'm having a lot of trouble with your English. If you are trying to assert some kind of conservation of energy which prevents the formation of the very exothermic UO3 during combustion, then it is you who is making claims aginst physical laws and established science. Why? Do you have financial ties to the nuclear industry? --James S. 08:42, 29 March 2006 (UTC)
With you petition? Do you get money from the lawyers of the golf war syndrom patients?--Stone 09:07, 29 March 2006 (UTC)
No, I do not. Interesting response. Please answer: Do you have financial ties to the nuclear industry? --James S. 09:57, 29 March 2006 (UTC)
No, I do not.--Stone 09:58, 29 March 2006 (UTC)
I see that your userpage indicates that you have contributed to the Chemical warfare article. Does your involvement with facts surrounding chemical warfare cause you to hope that uranium combustion can not be shown to produce uranyl gas(es)? --James S. 10:31, 29 March 2006 (UTC)
Anee de gasbomb de gasbomb (citation from Gerhardt Polt) —Preceding unsigned comment added by Stone (talk • contribs)
That looks like a yes, to me. --James S. 11:21, 29 March 2006 (UTC)

Condensation

The condensation from gas phase follows the rules of mass law. The air is oversaturated with uranium trioxide and the molecules have to follow the law and condense. This condensation is absolutely independent from which source the uranium trioxide molecules come from. How should the information stick to each molecule when to condense? --Stone 09:29, 28 March 2006 (UTC)

Could you please rephrase this question? What are you trying to get at? --James S. 06:36, 29 March 2006 (UTC)
Why should condensation from plasma have different mas law than that of sublimation?--Stone 06:44, 29 March 2006 (UTC)
Ions don't condense from plasma, they recombine. --James S. 06:49, 29 March 2006 (UTC)
What is the exact difference of molecules coming from 4000°C Flame tan that of 1000°C sublimation?--Stone 06:44, 29 March 2006 (UTC)
Sorry, I don't understand this question. --James S. 06:49, 29 March 2006 (UTC)
You state the gas doesn't follow the laws of gas and will not condense! Why?--Stone 06:58, 29 March 2006 (UTC)
I state no such thing; I have repeatedly stated that UO3(g) condenses. You are simply arguing for the sake of argument. Do you think that I will grow tired of such empty rhetoric and give up if you just keep typing in false, unsupported edits? --James S. 08:42, 29 March 2006 (UTC)
So everything condenses and nearly no molecule is in the gas phase anymore. Lets write exactly this in the article.--Stone 10:07, 29 March 2006 (UTC)
The article already says the gas condenses, in the first paragraph. What is your grade level in English? --James S. 10:15, 29 March 2006 (UTC)
What's your grade level in chemistry, mate? The paragraph as is stands is misleading, patently false even. At 2500 K UO3 will be in equilibrium with a host of other uranium oxides. Stating that UO3 will "eventually" condense insinuates that the vapor will hang around for an extended period of time, which it clearly won't. Ackermann's vapor pressure experiments show that. 129.215.37.163 12:23, 29 March 2006 (UTC)
It should also be noted that, above 800 K, UO3 (g) will condense to U3O8 (s), not UO3 (s), neatly in agreement with the described products of uranium combustion in the presence of sufficient oxygen and with the results of Salbu et al. Physchim62 (talk) 12:37, 29 March 2006 (UTC)

Please remember to sign comments

Note: Please sign your comments with --~~~~ or at least four tildes. --James S. 03:16, 29 March 2006 (UTC)

Sources

The point is and will always be why should a molecule with a low vapour pressure be a gas at normal conditions? A source for a example of this kind of behaviour would be good--Stone

Do you drink coffee, or tea? Have you noticed that steam stays in the air as a vapor before it condenses? Why should it?!? --James S. 08:42, 29 March 2006 (UTC)

The micro particles flying around nobody will deny, the caesium-137 or so from the spain steel factory and the atomic tests is also flying around, but as particles or condensed to dust particles.

The dust particles go into the lung if they have certain diamater, this is shown in many studies. Germany has problems with microparticle dust from diesel motors. Studies show that this particles and up in the lung.--Stone 07:04, 29 March 2006 (UTC)

This has nothing to do with uranyl oxide. --James S. 08:42, 29 March 2006 (UTC)

Problem finding UO3 infrequently ignored in Gmelin 8 1977 Uranium C1 page 98 can you state if this is the right page number?--Stone 07:13, 29 March 2006 (UTC)

Yes, it is. --James S. 08:42, 29 March 2006 (UTC)
Found it! The oxigen uptake of U3O8 is infrequently ignored. Have you read the rest of the stuff. The non stoechometrical compounds are everywhere and this statment does not say quantitivly! The Oxygen uptake is mentioned because: Of the statment in the midle of the section, that the statment that exact U3O8 is the substance formed by the reactions is never sure, because the U3O8 looses oxigen and takes up oxygen to form non stoechiometrical combounds. Do you really think this reearch should go into the article?--Stone 09:27, 29 March 2006 (UTC)
The whole page does not state any gasous UO3 like you put it in the article. Gmelin sas the uptake of ogygen of the U3O8 is infrequently ignored, this is a statment for the solid and not the gas phase. Remove the gasous from article!--Stone 09:31, 29 March 2006 (UTC)
Why don't you ask Professor Cotton his opinion? --James S. 10:06, 29 March 2006 (UTC)
Ask him! But no page in Gmelin states that UO3 is gasous combustion product of burning uranium. It has a long part about all aspects of UO3 but does not mention the UO3 molecules other than the ackerman paper (high temperature) argon matrix (deep temperature) or MS (low pressure). As fact some chemists state that the U3O8 is a mixed oxide UO2 2UO3 which makes it also a uranyl compound.--Stone 10:11, 29 March 2006 (UTC)
I agree with that. --James S. 10:16, 29 March 2006 (UTC)


back to the equation

Lets start wit the equation it self: can be found in [1]

log p= (((1.821 ± 0.075)· 104)/T) + 6.84 ± 0.58 log p= (((1.856 ± 0.016)· 104)/T) + 6.928 ± 0.103

I choose the first equation because it gives the higher pressure for UO3 gas.

log p= (((1.821 ± 0.075)· 104)/T) + 6.84 ± 0.58

Lets state 300K as the temperature (26°C or so)

putting in the numbers gives:

log p = -53.86

put both sides in the power over ten (native speaker needed)

p = 10-53.86 atm

p = 1.38 · 10-54 atm

convert from atm to Pa (1 atm = 101325 Pa)

p = 1.3985 · 10-49 Pa (N/m2)

Assuming that the laws of ideal gas are good for this problem

(which they are not, because the the condensation and the interaction between the molecules give even lower pressure for real gas at lower temperature than expected by the ideal gas euqaution)


p V= n R T

n = (p · V) / (R · T)

n =(1.3985 · 10-49 N/m2 · 1 m3)/ (8.314472 J · K-1 · mol-1 · 300 K)

n = 5.57 · 10-53 mol

so this is the number of mol per cubic meter of uranium trioxide.

1 mol = 6.023 · 1023 particles

So to get the number of particles in one cubic meter simpl multipie the numbers.

6.023 · 1023 5.57 · 10-53 = 3.35 · 10-29 particle per m3

Other way to point this numer is you need 2.98 · 1028 m3 to find on single atom of UO3.

Volume of earth 1.0832×1012 km3 = 1.0832×1021 m3 so even if the whole earth would be atmosphere there would be no molecule founnd in it. 600 times earth volume and you find your UO3.

The equations are right and the condensation follows this patter. Where am I wrong? This leads to no molecules in the gas phase after cooling at all.--Stone 10:32, 29 March 2006 (UTC)

How long does it take, in mean and median, for the average monomeric UO3 molecule to condense? How long does it take all of the molecules from 4,000 tons of burned uranium to condense? --James S. 10:43, 29 March 2006 (UTC)
Good point! Give me the numbers and everything is OK! If not this calculations show that condensation takesplace untill nothing is there anymore!--Stone 10:51, 29 March 2006 (UTC)
Yeah, well, the amount of dust in the air makes a big difference, bifurcating the distribution substantially. Good luck on getting the numbers from anyone but an empericist. --James S. 11:13, 29 March 2006 (UTC)
This is the point nobody does this kind of research and for that reason it should stay out of an enzyclopedia!--Stone 11:28, 29 March 2006 (UTC)

Cotton

Does Cotton give UO3 or simnply uranyl than it has to go!--Stone 11:10, 29 March 2006 (UTC)

In the ecosystem burned uranium goes from uranyl oxide gas to uranyl carbonate complexes to protein ligands. In other words, it ends up in the food chain. --James S. 11:17, 29 March 2006 (UTC)
I think you fight the wrong person at all!

Lets sat it the way it is:

Burning DU gives U3O8 UO3 UO2 in changing quantities. (Acording to differt literature) The condensed particle from this are small and do not settle qickly. The elevated radiation from UK during GW2 shows this clearly. Small particles get into the lung and due tue the fact that Uranyl compunds like UO3 dissolve quicker than U3O8 the toxicity of them is severe. This is absolutly OK.

My oppinion is, that DU is chemical warfare and only because its cheper than tungsten to poisen Irak and Yugoslavia with it is crimainal. The other nations use tungsten for ammunition and they know why! Is DU ammunition used in traing grounds in the US? I think they would not dare to do so, because theay get lawyers crawling around everywhere. --Stone 11:27, 29 March 2006 (UTC)

I agree. There are all sorts of oxides formed during combustion of uranium metal. Remember that the temperature reaches 2500 K, where UO3 and U3O8 are likely unstable towards oxygen loss. We can't really state that "monomeric UO3 is produced by combustion of uranium metal in air from 2200-2800 Kelvin" when the gas will quickly condense out and one is left with various uranium oxides as a fine dust. 129.215.37.163 12:13, 29 March 2006 (UTC)

Slowly but

The only thing to do is to get the first sentence to a state which makes clear that both cited references do not do the research indicated in the sentence bevor.

Ackermann no combustion
and the other no examination of the products
combustion product as main point in the sentence

Which is critical in my point of few.--Stone 11:33, 29 March 2006 (UTC)

Transport reaction

The transport reaction was OK I think. This is a example for UO3 molecules and could stay. The matrix experiments with single UO3 molecules where also resonable. --Stone 16:51, 29 March 2006 (UTC)

But all that material on the transport reaction is still there -- section "In the gas phase". So is the paragraph on the matrix experiment. 129.215.194.206 17:42, 29 March 2006 (UTC)

References section

The references section is almost as long as the article itself, and a fair number of the articles cited there seem not to be used. 129.215.195.81 14:57, 30 March 2006 (UTC)

Partial protection?

Given the recent phenomina of fresh anons reverting away source-supported statements, and apparently planning to delete sources, above, as their only edits here, I propose partial protection of the recent dispute-tagged version for a short while. Are there any objections? --James S. 22:55, 30 March 2006 (UTC)

Anon editing on Wikipedia is permitted per Jimbo's wishes. Also, unlike yours, the anons' edits make sense. Your request for semi-protection is a misuse of Wikipedia policy, it's outright trollery, in fact. Now go away. Wikipedia isn't a soapbox. 82.41.26.244 23:30, 30 March 2006 (UTC)
No protection. James, if you can't handle the heat get out of the kitchen. You have no right to demand protection just because other editors do not agree with you. --DV8 2XL 01:20, 31 March 2006 (UTC)
Are you saying that you no longer agree with the fact that UO3 is a combustion product of uranium? Then where does the 75% U3O8 particulate come from? look at the edits: reversion of lung fluid solubility half-time to "elimination" (which means excretion in urine or feces), reversion of the entire combustion product section which you copied to Uranium and other articles, reversion of the bond length discussion copied from Simon Cotton's book, and deletion of the entire See also section. And this from brand new anonymous editors who haven't edited anything else. Completly unsupported deletions of whole source-supported passages. Clearly this page should have partial protection. --James S. 05:52, 31 March 2006 (UTC)
When you start justifying your edits the conflict might even go away. Just give the reasoning why the combustion products should be discussed here instead of at uranium. 82.41.26.244 08:04, 31 March 2006 (UTC)
The other combustion products are relatively harmless compared to UO3 and the U3O8 which it condenses into, forming 75% of the combustion product. Since nobody has proposed an alternatve formation path for the U3O8 from the plasma combustion state, then the intermediate UO3 is the proper place to discuss the toxicology of all the uranyl-rich combustion products. There is simply no other source for any of the others, and UO2 isn't anywhere near as much of a problem. --James S. 18:19, 31 March 2006 (UTC)
The health impact of DU ammunition has its natural home in Depleted uranium. As others have said, the combustion products are likely U3O8, UO2 and other, lower oxides of uranium, and they aren't a gas, they are very fine dust. Why this insistence that UO3 is a gas formed during combustion of uranium? Why not say that various oxides, are formed and put that into the article on DU? Everyone here agrees that uranium oxides (whatever form they come in) aren't conducive to good health. 82.41.26.244 20:23, 31 March 2006 (UTC)

Does anyone care to defend this? --James S. 22:32, 31 March 2006 (UTC)

I told you a month ago if you dragged this issue into the chemistry topics you were going to draw a lot more heat than leaving it in DU. Don't be surprised that critics are crawling out of the woodwork now. --DV8 2XL 22:58, 31 March 2006 (UTC)
You're right, you did. There's still a solid case for partial protection of up to one week. --James S. 23:24, 31 March 2006 (UTC)
Bollocks. Look, mate, let's make this experiment - it's chemistry, and chemistry is an experimental science: You STEP BACK for a day, let the version minus dispute tag, combustion products and all the other rubbish stand and WAIT if anyone, any single person reverts to the version that you so eagerly push. 82.41.26.244 23:42, 31 March 2006 (UTC)

Combustion products

From a realy good article about: Volatilization of urania under strongly oxidizing conditions Journal of Nuclear Materials 346 (2005) 312–318 C.A. Alexander

If the oxygen partial pressure is held constant and the temperature raised, then the composition will shift to a lower value of the O/U ratio. Since the higher oxidation state at a specific temperature will have a more negative free energy,

This states higher temperature makes substances with more free energy unstable! --Stone 08:07, 31 March 2006 (UTC)

Because of the greater number of nuclei for those substances, the probability of an additional mechanical ionization increases substantially with the number of (heavier than hydrogen) atoms in the molecule. However, the cooling proportions remain the same, and the U3O8, which is 75% of the solid product, condenses from UO3(g), which dominates in plasma cooling, no matter what the peak temperature was. --James S. 18:26, 31 March 2006 (UTC)
That article also indicates, in its abstract, that uranyl hydroxide gas also exists in aerial equilibria. I bet its a high-humidity combustion product, too. --James S. 22:49, 31 March 2006 (UTC)

Structure

Article

Ther should be headlines for

Chemistry
Synthesis
Structure
Chemistry
Use
Production
Health and savety

like in most other articles. This article is and will be a mess! I will try to build up a new one User:Stone/Uraniumtrioxide leaving out

Combustion of Uranium
Uranium oxide gas

Which can be but in from somebody else!--Stone 08:18, 31 March 2006 (UTC)

Do you intend to include toxicology? --James S. 18:23, 31 March 2006 (UTC)
Toxic is part of Health and savety but we can renam it with toxicity or what ever!--Stone 09:43, 1 April 2006 (UTC)

Compound

O
||
O = U = O

is more accurate, taller, has many fewer characters than the graphic, and so it takes less time to load. --James S. 19:51, 31 March 2006 (UTC)

Diagnosis of exposure

Urine tests for isotope ratios are worthless, because the isotopes translocate at different rates. Anything less than chromosome analysis after one year is worthless. --James S. 19:58, 31 March 2006 (UTC)

{{fact}}?? The isotope effect for U-235 and U-238 is minimal, this isn't hydrogen and deuterium we are talking about. 82.41.26.244 20:25, 31 March 2006 (UTC)

Gmelin Handbook (1982) U-A7, pp. 300-320; cellular (biological) nuclear transport. Mass differences have acoustic phononic signatures yeilding different behavior with enzymatic and large-scale structural effects, e.g., chromosomes. Please check the recently-added references. --James S. 20:53, 31 March 2006 (UTC)
How so? The reduced masses of the systems will hardly be different, U-235 and U-238 are so much heavier than their bonding partners that they for all practical purposes behave like a brick wall. Vibration frequencies will for all practical purposes be identical. In all these papers on IR spectroscopy on uranium oxoanions one often sees O-16 and O-18 isotopomers, never U-235 and U-238-labeled compounds. 82.41.26.244 23:36, 31 March 2006 (UTC)
There are marked translocation differences in the isotopes of uranium at the citation given, but more importantly, uranyl ions are collected in the cellular nucleus, where they are unlikly to return to plasma (or any part of blood serum other than white blood cells) or urine. Uranium is often used to stain DNA. --James S. 01:15, 1 April 2006 (UTC)
To hear that the frequency difference is greater than the linewidth in condensed phase would be a surprise. Can you maybe point me to an abstract or something?! 82.41.26.244 23:36, 31 March 2006 (UTC)
I don't understand what you are asking. Some biochemical processes are very sensitive to small variations in isotope mass. Please see the Gmelin charts cited. --James S. 01:15, 1 April 2006 (UTC)
The different reaction rate of isotopomers (keyword isotopic effect) is due to a difference in zero-point energy. That difference can be measured in the vibrational spectrum. That in turn is dependent on the reduced mass, which is strongly dependent on the lighter partner and almost not at all in the heavier. Hence one would predict no change in reaction rate between U-235 and U-238. Can you point me to some original sources that Gmelin lists. I don't have Gmelin at hand online but can still get online journals on the weekend. 82.41.26.244 01:27, 1 April 2006 (UTC)
Sure, I would be glad to go to the library again, and especially for you, since you've reported me for 3RR after repeatedly inserting "elimination" where it didn't belong. However, please give me a few days, it's maybe still intersession. --James S. 02:47, 1 April 2006 (UTC)
You have been reported for 3RR violation for repeatedly inserting stuff that several people asked you to kindly put elsewhere. You are aware that you pissed off several people so much that they won't edit here any more, aren't you? Do continue, and you will be put on 1RR parole for your pet peeve (or hopefully ban you from it altogether). 82.41.26.244 17:19, 1 April 2006 (UTC)

Structural formulae

There is an currently edit war going on if the gas phase structure should be placed above or below the solid-state structure. We also now have a pretty graphic of the molecule in the gas phase.

My take on the matter:

  • The solid is the most frequently encountered form of the compound and as such it should take precedence
  • The graphic really shouldn't be here. 3D images are great for the finer geometric points of a structure, and 2D structural formulae are good for displaying connectivity and bond order. Problem is, there isn't really much data on the gas phase structure. That paper where the authors do IR spectroscopy in an argon matrix merely states that the molecule is distorted away from trigonal planar to space group C2v and do not give bond lengths or angles, just force constants. There is also a theoretical paper by Pykkö, according to which the molecule is trigonal planar. (Sadly, I haven't read the paper.) I would predict that Pykkö puts down the distortion to interaction of the molecule with the "inert" matrix. Someone who did read the paper, please confirm!
  • What would be great is a structure of the coordination polyhedra in the solid. Is someone at an institution where they subscribe to the ICSD and can contribute one?! 82.41.26.244 16:31, 1 April 2006 (UTC)
I added the PNGs. I'm really not fussed on where the images are used, if at all. I just think colour improves the article for casual readers! But the points you make are fair ones. If someone can find out the structure of the coordination polyhedra, I'll make a 3D image of them. And as for putting the gas phase structure above the solid state one, I really have no preference! Common sense would dictate the solid is more important because it is far more commonly encountered. Leave me a message on my talk page if you would like any more 3D images - I can tailor make them to your needs!  :) --Ben 16:59, 1 April 2006 (UTC).
I thought you study at Cambridge! The chemistry department doesn't subscribe to the ICSD at Cambridge? That is weak! 82.41.26.244 17:15, 1 April 2006 (UTC)
I'm sure they do, but I'm on long term leave from uni due to illness - that's why I have time to faff around on Wikipedia! --Ben 17:26, 1 April 2006 (UTC).

Busby, C. and S. Morgan

I have examined the work cited by James S. which was by C. Busby. After reading it I have come to the conclusion that it is less trustworthy than papers printed in more traditional chemical, physics or biological journals.

The paper is Busby, C. and S. Morgan (2006) "Did the use of Uranium weapons in Gulf War 2 result in contamination of Europe?" European Biology and Bioelectromagnetics, 1(5), 650-668.

  • Firstly the journal is not NPOV, and it deals with biological matters the paper which Busby et. al. published is on the measurement of radioactivity in the enviroment and transport in air of uranium, hence I would comment that the choice of journal is not correct for the paper. This work should have gone into a journal such as Radiochimica Acta (or another radiochemical) or a journal devoted to enviromental chemistry (measurement of species in the enviroment). I think that if the paper had been submitted to a journal such as Radiochimical Acta that in the present form it would not have been accepted for publication.
  • The results on uranium in air are so different to cesium (about three trustworthy sources give given graphs of Cs-137 concentration in air as a function of time in europe). The chernobyl cesium remained in the air for much longer than Busby has claimed that the uranium from the golf war did. I have found no comments in Busby's paper on this. If he has good reasons to believe that the uranium would behave so differently to cesium, then he should have included his reasoning in the paper. I do not know what the particle size in the fallout from the two different sources is, but this is a possible reason for a difference in behaviour. Yet in the paper this issue is not considered.
  • I think that Busby's work should be treated with some caution, from his web site (and an examination of his publication record in science journals) it does appear that he is strongly anti-nuclear. His input into the literature includes many letters to New Scientist in which he shares his views on matters of radioactivity. I think that he is not a balenced scientist, I think that we should exclude the above mentioned paper until someother scientist who is more likely to be NPOV can do similar work.Cadmium 17:27, 1 April 2006 (UTC)
I don't agree with you because this repport is based from the result of measurments in an official research center. How do you explain the fact at all the instruments mesured the same increase in radioactivity at that time? You cannot just ignore this fact. Where is this radioactivity comming from? Dominique
Cause and effect. Because there was a rise in uranium levels in a small area of Berkshire at roughly the same time as a bombing campaign in the middle East it cannot be assumed that the two are connected. At roughly the same time as those increases were measured I opened a tin of sardines in my kitchen. I could assume that the radiation came from my supper. I would be wrong. The radioactivity had to come from somewhere. If the measurements were localised then the best place to look for the source would be in the local area. Not hundreds of miles away. BRT01 19:34, 15 July 2006 (UTC)

Uranium trioxide in the gas phase

Why would the molecule be T shaped ? I know that a matrix isolation study has been cited, but in a condensed phase packing effects could distort the molecule from the shape found in the gas phase. Valence Shell Electron Pair Repulsion theory (VSEPR) which is one of the best predictive tools for simple molecules would predict a C3 trigonal shape like that of BF3.Cadmium 17:27, 1 April 2006 (UTC)

I added a trigonal planar UO3 2D structure a while ago, but James told me it was wrong, citing Lanthanide and Actinide Chemistry by Simon Cotton (1991 Edition apparently!). James has scanned the relevant page and uploaded it here. I don't know what the gas phase structure is, but if someone knows, I'll draw it from their description. I'm just the artist! --Ben 17:47, 1 April 2006 (UTC).
Pyykkö argues on one of his papers that there is a low-frequence mode in this compound. In other words its geometry is easily distorted. Dr Zak 19:24, 4 April 2006 (UTC)
That is actually why I'm not particularly partial to that "T-shaped" structure now. It isn't the "real" minimum, just a structure that the molecule takes under those conditions in the argon matrix. Dr Zak 19:42, 4 April 2006 (UTC)
The low frequency is from electron redistribution between levels 5f7/2 and 5f5/2 for the distant third middle oxygen, isn't it? --James S. 21:23, 4 April 2006 (UTC)

Why include all of the rare solid polymorphs while removing gas information?

Filling the article up with solid polymorph forms, while removing the source-supported statements about gas production is such obvious bias. This bias is made all the more obvious with the lung solubility reference to "elimination" -- a pharmokinetic term meaning excretion, urination, or perspiration, from the Morrow (1972) reference to lung fluid solubility -- certainly a much larger, plainly factual error than removing the reference to the controversial Busby article. It is so sad that so many people want to participate in supressing information about the gas phase. Why not just remove all references to water vapor from articles involving boiling water? --James S. 20:52, 2 April 2006 (UTC)

And another thing, Cadmium, why are your oxygen diameters so tiny? Your diagrams are seriously misleading. --James S. 20:58, 2 April 2006 (UTC)

Adding pictures and details of the crystal forms of UO3 is not a form or expression of bias, the pictures are easy to read. They have been generated using POV ray which is driven by free software which is the de facto standard for many chemists. If you feel strongly that the drawings are not clear then I can provide you with my POV ray source code, you can then edit it to make a new POV file to draw pictures. The vast majority of UO3 is in the form of the solid, so why do you feel compelled to show pictures of the molecule. I suspect that when compaired with neutron/X-ray diffraction that the evidence for the molecule which you so wish to show is not good evidence. What you need is diffraction data to get the bond lengths and angles.Cadmium 19:30, 3 April 2006 (UTC)
Why do you think that the diagram in Cotton's book isn't based on just such studies? Do you have access to the Science Citation Index? Those are easy to find. --James S. 20:22, 3 April 2006 (UTC)

Questions about reverts

Cadmium: I have these further questions about your recent reversion which is just a copy of others' reverts:

  • Why did you remove the NIST-style formula?
  • Why did you change "Partially soluble" to "soluble" -- do you have a single source claiming UO3 is more than half soluble in water in less than a month?
  • Why did you replace the abject falsehood that Morrow (1972) claims "elimination" instead of dog lung fluid solubility?
  • Why did you remove the fact that uranium produces UO3(g) when it burns in air? Cotton says it does, and Ackermann and Wilson explain the transitions which in turn explain the 75% U3O8 solid combustion product as a condensate. Alexander (2005) makes it even more clear that UO3 and uranyl hydroxide (in humid air) are both combustion products. The thermodynamic data shows that UO3 is the lowest energy state from plasma recombination. Do you have a single source claiming that UO3(g) is not a combustion product?
  • Why did you remove Cotton's molecular diagram and the paraphrase from his description of the molecule?
  • Why did you remove the equations from Wilson (1961)?
  • Why did you remove the citation to Hoekstra and Siegel (1958) and the thermodynamic data of Wanner and Forest (2004), both showing the instability of UO?
  • Why did you remove the quotation and citation of Gmelin about the uptake of O2 by U3O8 being not infrequently ignored?
  • Why did you replace the spelling error in the citation to Stradling et al. (2003b)?
  • Why did you delete the citation to Alexander, C.A. (2005) -- a reference which Stone provided, I might add?
  • Do you have anything more than a newspaper account of an unnamed government official opposing Busby?
  • Why did you remove the citation of Professor Cotton's book?
  • In what way have these changes made the article easier to read? Your edits show that you are simply jumping on the bandwagon, without putting any thought into your reversion. --James S. 20:22, 3 April 2006 (UTC)
  • Another question: Why did you replace five significant digits in the molecular mass? The isotope ratios frequently vary more than an AMU, between natural and depleted forms. --James S. 21:25, 3 April 2006 (UTC)
I would never claim that the version I reverted to was perfect, but it was much more easy to read than the state which you had left it in. I think that you should have added to the version with the details of the different crystal forms, rather than reverting away good and well accepted (peer reviewed) which is based on the literature crystal strcutures of UO3 in favour of the UO3 gas matter. You need to provide more of the book from which you scanned the diagram of a UO3 molecule. I have read the page you have provided from cotton and it does not say that it is describing UO3 in the gas state.Cadmium
All three pages of the UO3 section have been scanned in for five days now: p. 126, p. 127, p. 128. Cotton, Alexander (2005), and the thermodynamic data all show that uranyl oxide is the most likely combustion product, and Wilson (1961)/Ackermann (1960) explain how its condensation explains that U3O8 results as 75% of the resulting particulate product. Again I ask: Does anyone have any evidence or sources that UO3 gas is not produced as a combustion product? Surely if anyone had any such evidence, they would have brought it forward by now. Are there any legitimate motivations for continiously deleting any mention of the gas combustion product? Obviously the fact is embarrassing to many, but that is not a reason for scrubbing any mention of the gas. --James S. 20:38, 4 April 2006 (UTC)
I have read thorugh the rest of the section which you have scanned, and yes as expected it does say that the oxidation of uranium and the lower oxidation state compounds does lead to uranyl compounds, but even close to your red arrow it does not say that UO3 gas is formed. I think that the diagram that you have of the UO3 molecule is not a diagram of a vapour phase UO3 molecule. Some matrix isolation work has been done on UO3 ( The Journal of Chemical Physics -- November 1, 1980 -- Volume 73, Issue 9, pp. 4207-4216), this does claim a T shaped geometry. But in a noble gas matrix the UO3 is in a condensed phase which is different to the gas phase.Cadmium
Regarding the significant digits, the atomic masses are derived from the natural isotope distribution, which for uranium is actually quite constant. The mass of light elements like sulphur or boron is much more variable. People "know" that the atomic mass of commercially available uranium (or lithium or hydrogen) sometimes varies, and for analytical work where accuracy is required one must find out what the atomic mass of that particular batch actually is. Dr Zak 20:25, 4 April 2006 (UTC)

Uranium

The Uranium trioxid GAS also found its way into the uranium page! As combustion product!--Stone 09:11, 5 April 2006 (UTC)

I didn't put it there, DV8 2XL did, seriously. --James S. 12:07, 9 April 2006 (UTC)

After reading the all the sources

I found no indication that there is no source for Uranium trioxide as primary combustion product. So I will delet the unsourced citations.--Stone 13:49, 5 April 2006 (UTC)

I'm not sure whether to simply agree with your double negative, or ask you how you read the thermodynamic data without concluding that the 75% U3O8 solid product is the result of UO3(g) condensation and decomposition. In any case, you really shouldn't be claiming English proficiency at the level you do on your user page. Thank you for citing Alexander (2005) -- that table of partial pressures is most illustrative. --James S. 14:32, 5 April 2006 (UTC)

Polymorphs

I think that each polymorph does need its own subsection, I intend to add more on each one. For some forms more than one diagram is needed. James has compressed the solid state chemistry into too small a space for it to be clear. I agree that under some comditions that UO3 gas can exist, but the solid state is more important as the vast majoirty of the chemistry of UO3 is of the solid.Cadmium

Couldn't agree more. Dr Zak 18:49, 5 April 2006 (UTC)
Sure, it would be appropriate when there is more than just an image and a few sentences for each. --James S. 20:23, 5 April 2006 (UTC)

There is non combustion study in literature

As there is only the combination of wilsom and ackermann this is simply not enough to claim combustion product. The found combustion product in kuwait tank fire is probably UO3 which is als not enough to claim UO3 combustion product.--Stone 08:10, 6 April 2006 (UTC)

You neglect Cotton's explicit statement about aerial oxidation, the thermodynamic data, and your own reference Alexander (2005) which shows the increasing partial pressures below the burning temperature. You also have suggested no alternative hypothesis to explain how the U3O8 comprising 75% of the particulate forms. --James S. 16:08, 6 April 2006 (UTC)

Ther is no combustion mentioned! Cotton states uranyl compounds nothing else! If I state they rise from the quantum vacuum, this would also be possibel but also unreferenced!--Stone 07:31, 7 April 2006 (UTC)

"Aerial oxidation" includes combustion. There are no other uranyl oxides. Your comments about the quantum vacuum are meaningless. Above, I asked you:
I see that your userpage indicates that you have contributed to the Chemical warfare article. Does your involvement with facts surrounding chemical warfare cause you to hope that uranium combustion can not be shown to produce uranyl gas(es)? --James S. 10:31, 29 March 2006 (UTC)
to which you replied:
Anee de gasbomb de gasbomb (citation from Gerhardt Polt)
Do you care to elaborate on that answer? It seems to me that you have provided no evidence whatsoever that UO3(g) is not produced in uranium combustion, against the exposition of Cotton, the thermodynamic values, the explanation of the U3O8 crystals from condensation and decomposition shown by Ackermann and Wilson, and the emperical evidence of Salbu, et al.
Why are you so opposed to the fact that gaseous UO3 is produced when uranium burns in air?
Why haven't you been able to show any sources at all suggesting that UO3(g) is not a combustion product?
Why do you keep deleting any mention of UO3(g), or complaining to other people and insisting that they delete any mention of it for you?
What does this have to do with your experience with chemical warfare? --James S. 21:44, 7 April 2006 (UTC)

Are you afraide to have a opponent with high level experience of Chemical warfare? The G. Schrader working group was always my favorit for phosphor chemistry and the Labwork of Haber and Grignard on sulfide chemistry are also a highlight of french and german chemistry!--Stone 08:02, 11 April 2006 (UTC)

No, but it would be great if you would please answer the questions instead of going off on that irrelivant tangent. --James S. 19:18, 11 April 2006 (UTC)

Let's also mention that the vapor pressure of UO3 at 980 °C is 10 nanobars or to. Someone who breathes in the gas has other things to worry about that gaseous combustion products of uranium.

Great; let's also mention that it's obviously greater than that of UO2 at 2500 K. You have no sources for your statement -- most people going into battle escape without obvious injury. The number of health effects being suffered by combatants in the February, 1991 Gulf War is in the hundreds of thousands, and no alternative hypothesis for their injury remains of the dozen proposed in the 1990s. --James S. 19:18, 11 April 2006 (UTC)

Equilibrium and transport reaction are the same

To mention pot in a long section is a little bit more than necesarry. The whole article will benedit from som tidy up.--Stone 08:10, 6 April 2006 (UTC)

What? "pot"? --James S. 16:02, 6 April 2006 (UTC)

MOVE of some structures? and copyvio?

After redoing all the literature and adding use and Production I think the structures of the delta and the beta form could have their place on the supplementary page? These pictures are good, but they take a lot of space and load.--Stone 10:29, 6 April 2006 (UTC)

Why? Wikipedia isn't a paper encyclopedia. --James S. 16:05, 6 April 2006 (UTC)

The links to the scanned and downloaded pdfs of www.bovik.org have a questionable legal status here in Europe, and I do not know what the rights owners would think if they find them linked to this article. We know them an most of us red them so why keep them on the front page? Put them to the talk page or so than anybody interested in the little uraniumoxide controversy can download them from there.--Stone

As part of petitioning activities, I've got U.S. fair use rights to keep them up; what is your source for suggesting a link to proprietary data is a potential copyright violation? If the www.cheetos.com site is copyrighted, you can still link to it from the Cheetos article. --James S. 16:05, 6 April 2006 (UTC)

If you realy want I write a letter to elsevier, that you use their articles on this page. --Stone 07:29, 7 April 2006 (UTC)

Why would you want to do that? The use of educational material as part of petitioning activities is one of the widest fair use rights in the U.S., with settled precident allowing electronic redistribution of entire articles such as those on www.bovik.org. Simply linking to those fair use articles on my site doesn't consitute a copyright violation anywhere. --James S. 21:47, 7 April 2006 (UTC)

structures

Still have the feeling that the structures take mor place than necesarry--Stone 07:33, 7 April 2006 (UTC)

I feel I need to comment

I realize this is a big edit war (in which I have no desire to get involved), but I condensed the production section and removed the other two times it is brought up.

Here are my suggestions for the article. It would be preferable for this to follow the WikiChemicals template, but if I were to ignore that for a second:

  • I would change the Chemistry section into 'Structure and Reactivity.' I would put the solid phase stuctures first, and organize the darn pictures. The gas phase section (the dispute in question), needs to be cleaned up. As far as I can tell, there is no "true" gas phase structural data here--matrix data may be monomeric, but is not truly gas phase, and is not entirely convincing. The vapor pressure data and equilibria are not well presented; while they make the point that UO3 may be volatile (barely, at really high temperatures) at some conditions, they stylistically stick out, and are confusing to the unknowing reader. That is, there is no context for understanding why that data is presented. The calculation is nice, but does not flow well in the text and could be labelled as "Calculated Structure"; perhaps some of the detail could be omitted and cited instead.
  • It would be nice to have the reactivity data offset from the structural data--right now it's in the structure section which is confusion.
  • The ceramics section is a use (sorta) and in reality should be in Production and Use. (It would be nice if a separate Use section could be developed that restated, perhaps in more detail, the nuclear entrichment/recovery and the ceramics).
  • I would then put the the Health Risks, after the properties and uses have all been discussed.

Right now this article is a big mess. Olin

Thank you for all your hard work with the footnote-style references. I don't have the hang of those yet, and it's nice to see someone adding work instead of taking facts away from this article for a change. Thanks to Cadmium, too, for adding all the solid state structure diagrams.

However, having said that, I don't understand Cadmium's latest structure calculations, so I'm going to move them here to the talk page. --James S. 07:58, 9 April 2006 (UTC)

Unclear valence calculation

While I thank Cadmium for adding this, I admit I do not understand it yet:

It is possible by bond valence calculations[2] it is possible to estimate how great a contribution a given oxygen atom is making to the assumed valence of uranium. Zachariasen, J. Less Common Met., 1978, 62, 1-7. Lists the parameters to allow such calculations to be done for many of the actinides.

The formula to use is

s = e − (R − Ro) / B

For uranium binding to oxygen the constants Ro and B are tabulated in the table below. For each oxidation state use the parameters from the table shown below.

Oxidation state Ro B
U(VI) 2.08Å 0.35
U(V) 2.10Å 0.35
U(IV) 2.13Å 0.35

It is possible to do these calculations on a scrap of paper (old skool method) or software which does it can be obtained free of charge.[3][4]

Using a 6Å x 6Å x 6Å box with the uranium atom in the centre the bond valence calculation was performed for both U1 and U2 in the delta phase of uranium trioxide. It was found using the parameters for U(VI) that the calculated oxidation states for U1 and U2 are 6.78 and 6.13.

I guess my main questions are:
  • What is s?
  • What is R?
Explaining those would really help with the formula.

R is the distance from the oxygen to the uranium atom s is the contribution to the oxidation state of the uranium atom made by that bond, the total of all the s values gives the oxidation state. Ro and B are constants which have been worked out by looking at lots of crystal lattices. So the parameters are derived from experimental results.Cadmium

Also, perhaps the phrase "a scrap of paper (old skool method)" is somewhat unencyclopedic. --James S. 08:07, 9 April 2006 (UTC)
OK fair cop the phrase "a scrap of paper (old skool method)" is a bit too tounge in cheek, many laszy people use software to do it, I tend to use excel spreadsheets but if you are super keen you can do it on a scrap of paper. By the way thanks James for making the formula look more pretty, I assume that you are responsible for formatting it into the nice curtrent state. The thing about these calculations is that in this case they point out what you already might know but in the case of U3O8 they do say something which is interesting.Cadmium
Alright, I understand the calculation now, but aren't the emperical studies better to include than this estimate? --James S. 19:19, 11 April 2006 (UTC)

Questions for Dr Zak

Regarding these edits,

  • Why did you claim that the intro paragraph, which cites two sources directly and is comprised only of previously-uncontested statements, was unsupported?
Ackermann says otherwise. Besides, the compound does not sublime from U3O8, the only correct way to state the facts is that it is in equilibrium with U3O8 and oxygen. And below 800 °C or so the equilibrium is reached so slowly that no vapor can be detected at all, certainly not at room temperature.
Ackermann says otherwise what? True, I should have written "reacts" instead of "sublimates." We agree that low temperatures don't matter, but uranium burns above 2500 K.
Combustion of uranium is a specific reaction and thus that sentence ought not to be in the introduction. Put it in uranium as it is a reaction of uranium. Besides, UO3 gas is a minor component of the combustion products and always in equilibrium with other uranium oxides.
Note that the intro paragraph only refers to the temperature of uranium combustion, not combustion itsself.
Go to uranium. At 2500 K a whole host of oxides are formed, of which UO3 is at most a minor component.
Source? --James S. 20:29, 10 April 2006 (UTC)
The higher uranium oxides (UO3 and U3O8) are unstable towards loss of oxygen at elevated temperatures. Have you not seen the phase the phase diagrams in Gmelin? —Preceding unsigned comment added by Stone (talk • contribs)
Well of course, I scanned them in for everyone to see and have repeatedly referred to them. However, we're discussing gas, not solid phase. --James S. 19:22, 11 April 2006 (UTC)
  • Why do you continue to remove the explanation that hexavalent means the (VI) oxidation state from the hazards section?
Because it is just superfluous. The formalism to write down the oxidation state is well-established, and in the first paragraph it already says so.
I disagree. You're not supposed to assume any level of technical background. There is no harm in leaving the explanation in: it doesn't hurt anything and it may help people unfamiliar with the terminology.
Wikipedia isn't the Health and Safety manual. Actually, the first paragraph says "hexavalent", so the H & S section should read "Like all uranium (VI) compounds ...". It did say that ages ago, before the edit war started, didn't it?!
Ha! As if this article ever existed without controversy and constant mindless reversion by those who would prefer that it simply not discuss certain topics.
  • Why do you claim that Cotton's molecular diagram in the Gas phase section is wrong?
This diagram is from a section in Gmelin that deals specifically with UO22+, the uranyl cation. While it's true that one can formally write down UO3 as <UO22+O2- (and this is a useful formalism for electron counting) one must always remember that molecules are flexible. Specifically, when one bends the linear UO2fragment, this will raise the energy of that fragment by increasing the repulsion between the oxygen atoms and weakening the U-O-bond. One gains more energy, though, by binding the O2- ion. This (orbital energies) is what one reads from a Walsh diagram.
No, the diagram is from Cotton's book, not Gmelin, and it's the low energy state, regardless of how flexible the bonds are. The exposition you've replaced it with is difficult to read, ungrammatical, and inaccessable compared to the diagram.
Ungrammatical it may be. It is however, correct and verifiable. Cotton talks about the uranyl cation. Period.
Wrong: note the three oxygens in that diagram. When Cotton says, "the close approach of two oxygens prevents the close approach of a third," is that talking about the ion or the UO3 molecule?
The paragraph starts "The bonding in the uranyl ion ...", so he must be talking about the uranyl ion. The whole section is about the uranyl ion.
  • How can you claim that Cotton's diagram is wrong when your own text that you replaced it with says the molecule is T-shaped?
Is it really T-shaped? The molecule is certainly T-shaped in an argon matrix, but do we have proof that it is T-shaped in the vapor? There is a paper by Pyykkö, who argues that the molecule is very flexible (in other words that the energy minimum is very shallow.)
Your exposition says it is. Cotton says it is. NIST says it is. The standard for inclusion in Wikipedia is verifiability, not truth.
Cotton is from 1991 (and not talking about UO3). Pyykkö is from 1994.
Oh, please. There's a new edition of Cotton's book dated 2004, and as far as I can tell that section isn't updated at all.
Not my fault. Have a nice day.
  • Why do you replace the equations showing combustion product cooling taken directly from Wilson (1961) with an equilibrium which is inappropriate for describing cooling behavior?
The two formalisms are actually equivalent, believe it or not. At higher temperatures, where the equilibrium is actually reached reasonably fast (and in Ackermann's paper it is) it is just nicer to write down the equilibrium as such - every chemist knows that equilibria are temperature-dependent.
They may be equivalent, but one is source supported and explicitly describes cooling, and the other you just made up without any sources.
You don't need sources to write down a reaction equation if that is what you mean. Also, copy-and-paste work from half-understood papers isn't building an encyclopedia.
So why do you object to the obvious inference that UO3(g) is a combustion product?
Now where does the version of yours (the equilibrium written as transport reaction) imply that UO3 is a combustion product? Both versions state the same thing - at higher temperatures move UO3 vapor is present in the gas phase in equilibrium with solid U3O8. Ackermann even gives numbers for the vapor pressure.
  • Why did you again delete the Gmelin quote about the uptake of O2 by U3O8 being not infrequently ignored?
Gmelin is talking about U3O8. Go to triuranium octaoxide, put the facts in there, over there they are pertinent.
They are just as pertinent here, as UO3(g) is the reaction product.
Gmelin talks about triuranium octaoxide samples often being nonstoichometric and containing a little more oxygen that the sum formula suggests. It never talks about the oxidation going all the way to UO3.
Huh? What page number are you referring to?
Huh? The page with that sentence on.
  • Why did you delete all mention of the proportion of uranium combustion products from Gilchrist, et al. (1978)?
Does not belong here. Go to uranium
Nonsense. The values explain where the UO3 predicted by thermodynamic values (goes).
Bollocks. Enthalpies of formation from the elements tell nothing about the stability of any compound. What is important is if there are any thermodynamically more stable decomposition products.
Unless, for example, uranium is being burned by the ton close enough to where people can breathe the vapors before they condense.
The partial pressure (in equilibrium with solid U3O8) at 980 °C is 10 nanobars. Somone who breathes in gas of that temparature shouldn't worry about uranium vapor.
  • Why did you delete the entire table of thermodynamic enthalpies of uranium oxide gas formation from Alexander (2005)?
Does not belong here. Go to uranium oxides
Nonsense. UO3 is explicitly included in the table.
Put the relevant data points into the infobox then.
The infobox? It's already too big.
It has space for thermochemical data.

Just as I suspected, simply providing the fully source-supported facts which directly imply that UO3(g) is a combustion product results in just as much vandalistic deletionism as the fact which follows from them. The true color of censorship has never been so obvious. --James S. 15:40, 10 April 2006 (UTC)

No one is out to censor anything here. We are building an encyclopedia on verifiable facts. Extreme views are subject to extra scrutiny. Dr Zak 16:38, 10 April 2006 (UTC)
The fully source-supported information I've included is not extreme views. You might not like it because of the political implications, you and many others, but the facts are verifiable. I will continue to revert such changes as vandalism without further comment here. --James S. 17:24, 10 April 2006 (UTC)
On that point: Is it your opinion that uranium combustion producing UO3(g) is an extreme view? Do you deny it? Do you have any evidence that it is not a combustion product? Given all the evidence that it is (e.g., where else does the 75% U3O8 come from?) then isn't opposition to the fact more extreme? --James S. 17:44, 10 April 2006 (UTC)
Earning ourselves another 3RR block for pigheadedness, aren't we? Dr Zak 18:11, 10 April 2006 (UTC)
Would you mind answering the question? If you want to complain about reverts, note that you have replaced spelling errors I corrected in the References section twice today now. You could at least have the courtesy to look at what you are doing before you revert. --James S. 18:40, 10 April 2006 (UTC)
Pot, meet Kettle. Dr Zak 19:23, 10 April 2006 (UTC)
Are you going to answer the questions, or not? --James S. 19:06, 11 April 2006 (UTC)

Editorial comments

  • Sublimation is a change from solid to gas. As written, this is a reaction, not a sublimation.
True; my fault, I will fix that.
  • Hundreds of Pascals is nothing if 1 atm is 101 kPa = 101,000 Pa; this hardly qualifies as "highly volatile" in a chemical sense by any stretch of the imagnination.
I should have written "several hundred Pascals," or "a substantial fraction of an atmosphere," as those phrases are perhaps more accurate.
  • There is no comma between a name and "et al."
So, fix it.
  • What do the units %atm mean? Do they mean atm x 100? Standard, chemical units are preferred. Olin 15:45, 10 April 2006 (UTC)
Yeah, atm*100. I thought it would be helpful to express partial pressures in those terms to illustrate the volatility. I'll convert to mbar. --James S. 17:29, 10 April 2006 (UTC)
  • The table "Thermodynamic enthalpies of uranium oxide gas formation" doesn't have a single enthalpy in it. I would like to know what temperature the free energies are calculated at; using them to determine stability at another tempertature is worthless. (Alternatively, the DS and DH could be provided.)
Yes, it's from STP, which I will note. Aren't the ratios between the energies going to be the same as formation at higher temperatures and pressures? If not, why not?
No: See below. Furthermore, the DIFFERENCE in free energy is what determines ratios. Olin 23:19, 11 April 2006 (UTC)
  • Also, the two different columns in this table are from two sources, implying that the data was obtained under the same conditions, which is doubtful; a caption explaining the different conditions is necessary. Reading the blurb in the Gilchrist reference, it sounds like (although it's hard to tell) the solid particulates are the rough percentages after the combustion has cooled. They don't sound like particularly great numbers, and I can't tell from the reference where those percentages come from. Olin 23:47, 10 April 2006 (UTC)
Both sources are listed at the base of the table. I agree that the Gilchrist report aren't great numbers, but they are the only uranium combustion product composition, other than Salbu et al. (2005) which I have been able to find. --James S. 05:47, 11 April 2006 (UTC)
I don't get the sense that they are very accurate; I still don't see what experimental technique they used to get them--please provide more information. If the ΔG's are at 298 K, they say nothing about the stability at 2100 K; you can't calculate an equilibrium constant at 2100 K from this data, for example.
But the ratios relative to the STP state are going to be the same: UO3 is at 2000 K going to give twice as much energy as UO2. --James S. 19:06, 11 April 2006 (UTC) I'm sorry, that was just a stupid comment proving I'd forgotten that the free energy of formation is a function of the enthalpy less the temperature times the entropy, which you correctly point out. --James S. 00:30, 12 April 2006 (UTC)
The ratios of substances are not the same at different temperatures, and the difference in free energy (not the ratio) is what is imporant. There is a dependence on the ratios of an equilibrium. ΔGο = -ln K, where K is a ratio of substances. And since ΔGο = ΔHο - T ΔSο, there could be a large difference in the ratio of substances. Again, it tells you a lot. The van't Hoft equation, found in any general chemistry book, describes this relationship. Futhermore, the "ο" is what tells you you are in the standard state, but you have to specify the temperature. Olin 23:19, 11 April 2006 (UTC)
Furthermore, STP is probably not what you mean. You mean standard conditions, which is 1 bar or 1 atm pressure, depending on the source; the temperature can vary. STP refers to the ideal gas law.
Oh, come on. It's close enough -- if you think that needs clarification, please go ahead. --James S. 19:06, 11 April 2006 (UTC)
It is not close enough. If you look at any physical chemistry book, it's a big deal what the difference is. I would take points off my chemistry students if they did this. I don't know what's written in your source, nor do I have all the data I need to fix this. I would need the ΔH's and ΔS's, or the complete temperature dependence data. Again, ΔG at 298 K (which I'm assuming is your temperature, still unclear), is a lot different for almost all reactions than that at 2100 K. Olin 23:19, 11 April 2006 (UTC)
Sigh! You are right. I have deleted the table. Please see the source yourself: Table V.4 on p. 98 -- it does contain ΔfHom and ΔSom. My question was, isn't the ratio of the free energy of formation between the two exothermic UO2 and UO3 gases going to be the same? [Answer: No] I understand that the ratios of the products depend on the differences, which will vary quite a bit under temperature changes. I'm just trying to suggest that UO3(g) is always going to be more likely than UO2(g) without regard to the temperature, which seems obvious since U3O8 represents 75% of the product. --James S. 00:19, 12 April 2006 (UTC)
You forgot to convert the entropies to kJ/(K*mol) (or enthalpies to J/mol). You also have to do the reactions from the elements in the standard state, since the standard entropy of any substance above 0 K is greater than 0 J/K (otherwise, the free energies of formation aren't referenced properly). If you don't do that, you get an erroneous number because you haven't taken the entropy into acount (most free energies of formation then would be negative!) So, you have to include the entropies of solid uranium and entropy of oxygen in your calculation.
Doh! Right; sorry. --James S. 03:40, 12 April 2006 (UTC)
You also might want to do the calculation for α-U3O8(s) to be complete. My CRC (72nd ed., p 5-57) lists ΔHfο = -854.4 kcal/mol, or -3,570 kJ/mol and Sο = 67.54 cal/(K * mol) = 282.6 J/(K/mol). I may do the calculation myself, but tomorrow, when I'm less tired. (Is this original research?) Olin 01:55, 12 April 2006 (UTC)
Me, too. No, we are allowed to convert units and similarly use published formulae. --James S. 03:40, 12 April 2006 (UTC)
Due to family engagements, I won't be able to contribute for a few days. Olin 12:23, 12 April 2006 (UTC)
You also need to include whether the ΔG's refer to the solid or liquids or gases, and which form of UO3 to be complete. Otherwise, the table is useless. Also "Thermodynamic Energies" still doesn't describe the data on the table: "Free energies"? Olin 15:13, 11 April 2006 (UTC)
Gases are clearly marked, on the table heading and each row, as they are in the source. --James S. 19:06, 11 April 2006 (UTC)

Image taken from Cotton (1991)

I have serious doubts about Image:UO3.jpg, the image that is continually being re-inserted by James to illustrate structure of the UO3 molecule in the gas phase. Caption: "Diagram of a uranyl oxide molecule. The formation of two short U=O bonds in the uranyl ion prevents the closer approach of the third oxygen " James has kindly provided the context here.

The paragraph the image is taken from talks about structure and bonding in UO22+, the uranyl cation.

Anyone got any thoughts on the suitability? If unsuitable, please remove! Dr Zak 19:09, 10 April 2006 (UTC)

I would vote for the removal of the pencil like drawing that you are talking about, I have read the whole of the source which James cited (Cotton) and it is not stating that it is the gas phase strucutre.Cadmium

I would concur that the diagram has nothing to do with gases UO3. Olin 23:22, 10 April 2006 (UTC)

Why?!? If it's a uranyl ion, what is the third oxygen doing in it? --James S. 05:44, 11 April 2006 (UTC)

The third oxygen is a place holder for any ion trying to get close to the uranium, this is described by cotton.--Stone 07:56, 11 April 2006 (UTC)

And we must not forget that the uranyl cation is most frequently encountered in aqueous solutions, where oxygen (from water) would be a ligand. Dr Zak 14:05, 11 April 2006 (UTC)

Okay, again, but given that it has the same diameter, why is the diagram an unsuitable illustration of UO3? It is exactly the same as is described by pther sources, plus it has bond lengths dimentioned in angstroms. How can anyone object to its inclusion as an illustration of the molecule? I guess I should be happy that we are now arguing about completely inconsequential things. --James S. 19:06, 11 April 2006 (UTC)
Calling the structure of a compound "completely inconsequential"? Man, you are a star! For starters, we do not know what the energy minimum of UO3 looks like. Pyykkö leads us to believe that it is in fact trigonal planar and the T-shaped structure that is displays in an argon matrix is merely to the conditions in the matrix. Why is the image unsuitable? Because is is an image of the uranyl cation. Because is insinuates that there are two oxygens rigidly held 180 ° apart that prevent the approach of any third ligand. Dr Zak 20:38, 11 April 2006 (UTC)
Okay, sure, then, include Pyykkö's description and a citation to Pyykkö's paper, but include it along with, and not instead of the T-shaped description described by Cotton, NIST, and your own argon matrix analysis. A neutral point of view means including the source-supported statements on both sides of an issue, not just the one with which you happen to agree. If you take yout the Cotton image again, I'll replace it without any further comment here. --James S. 21:59, 11 April 2006 (UTC)
By the way, can you explain why you re-introduced the section that begins "The geometry of the uranyl ion has been the subject of much debate ... amd the picture despite the fact that it is about the uranyl ion, not uranium trioxide, a fact that has been explained to you multiple times already? I did mention that the molecule is T-shaped in a noble gas matrix already. Dr Zak 22:04, 11 April 2006 (UTC)
This is nothing to do with my POV, but you can't cite the NIST website's diagram of a UO3 molecule as a reliable source indicating its T-shape, because many of their other diagrams show molecules as T-shaped, when in fact everyone knows they're trigonal or some other non-right-angled shape. You can't trust NIST's images for geometry, only for connectivity. Having said that, most trigonal molecules are properly represented, such as boron trifluoride, but some are most definitely wrong, e.g. sulfur trioxide - SO3 is trigonal planar, not T-shaped. Greenwood & Earnshaw say: "In the gas phase, monomeric SO3 has a planar (D3h) structure..." and their diagram shows a trigonal molecule with O-S-O bond angles of 120°. So don't trust NIST! --Ben 22:21, 11 April 2006 (UTC).
The diagram which I have just removed, is of a urnayl cation showing how a equitorial oxygen can not get as close as the axial oxygens. Please do not revert this change away. Please read the whole of the source from where you got it. If you want it I can draw you a nicer looking diagram using POVray and the bond lengths given in another source which is in the page. One of the advantages of my POVray is that it is better for Wikipedia in terms of legal matters.Cadmium
Please do. --James S. 00:15, 12 April 2006 (UTC)
And be kind enough to put the diagram of the uranyl ion on the page on the uranyl ion. Dr Zak 14:32, 12 April 2006 (UTC)

Some points

  • Citation in the introduction is a don't.
Fine. --James S. 19:06, 11 April 2006 (UTC)
  • The Uranium gas is or combustion is not more important than the other uses and chemistry. So if this goes into the introduction the other uses and the chemistry should also go there.
That is your opinion, and the thousands of soldiers and civilians who suffer increased birth defects in their children and other symptoms of Gulf War syndrome would disagree, as would I. --James S. 19:06, 11 April 2006 (UTC)

Quote from above:Do you drink coffee, or tea? Have you noticed that steam stays in the air as a vapor before it condenses? Why should it?!? Steam has missleading use. Vapor sometimes too. Gas or gas phase are the only with clear use. The vapor of water is a gas, steam should also consist of nothing than free molecules. But it is used as steam which you can see as white cloude,than it is no vapor or steam anymore but fine droplets of water in air. Two phase system which has already the condensation done. Vapor above a tee cup forms a cloude or fog or what ever you would call it. Drink a cup of tee at -20°C and you would see that all the water formes small dropps which freeze. The same will be in the case of Uraniumtrioxide. So you have small particles no vapor, gas or steam anymore. --Stone 07:56, 11 April 2006 (UTC)

On the contrary, some of the vapor will dissolve into humidity, even below freezing. --James S. 19:06, 11 April 2006 (UTC)
Go 2000° below the boilingpoint and you get nothing.--Stone 20:05, 11 April 2006 (UTC)
That's just not true -- the gas diffuses, and it won't condense unless it gloms on to other particles. Some proportion will always escape as a monomeric gas, and condense as such without other UO3 molecules, and some will be inhaled as such if there are people breathing in the area. --James S. 21:16, 11 April 2006 (UTC)
Then they will inhale the solid. If they inhale isolated gas molecules they will be to diluted to me measurable. Dr Zak 22:06, 11 April 2006 (UTC)
That depends on what you can measure. Gonocyte and lynphocyte chromosomes can evidently be used to measure no more than what pilots who never came any closer than a few hundred feet to their 30 mm ammo fires, and if that included solid particulates then they would still have traces of the insoluble UO2 in their urine, which they don't. --James S. 01:30, 12 April 2006 (UTC)
Drinking water contains "large" amounts of uranium compared wat you can meassure. So if they can not meassure the increase in the pilots, the effect of the uranium from drinking water is bigger than that of inhalation!--Stone 06:51, 13 April 2006 (UTC)
Since about 2001, all of the urine studies have involved isotope ratios, which can tell the difference between natural and depleted UO2 particulate exposure, but can not detect soluble uranyl exposure such as UO3(g) or U3O8(s) particle inhalation. --James S. 07:33, 13 April 2006 (UTC)

Equilibrium arrow

The equilibrium arrow doesn't come up right on my computer. I use:

⇌

which is a unicode thingy. I'll put it in. I'm glad we're treating two equations that are the microscopic reverse of each other as an equilibrium, since that is appropriate. Olin 15:07, 11 April 2006 (UTC)

You can just use &#8652;, because the default Wikimedia encoding has been UTF-8 for a few years now. --James S. 19:06, 11 April 2006 (UTC)

⇌ looks like a small square on my one.--Stone 20:04, 11 April 2006 (UTC)

You need to use a Unicode-capable font, such as Lucida. Here are some math-mode possibilities which don't depend on the client having an up-to-date Unicode font:
\overrightarrow{\gets} <math>\overrightarrow{\gets}</math>,
\overrightarrow{\leftharpoondown} <math>\overrightarrow{\leftharpoondown}</math>, and:
\iff <math>\iff</math> --James S. 22:14, 11 April 2006 (UTC)


At Max-Planck-Institute everything looks fine.--134.105.224.211 06:01, 12 April 2006 (UTC)

consensus on the word 'volatile'

Volatile is defined as "Evaporating readily at normal temperatures and pressures." or "That can be readily vaporized." [5] A few mbar of pressure high temperatures does not qualify as volatile, in my book, so I'd like to see if others agree thw word volatile should be stricken from the page. (Also, volatility is an innate property of a substance. "Volatile by oxidation" seems incorrect to me.) Olin 15:42, 12 April 2006 (UTC)

Couldn't agree more. If something is volatile it evaporates noticeably at normal temperature. Some people might call mercury volatile because the effects of its vapor are noticeable at room temperature and one must take precautions. But calling a thing volatile that is a gas only at incandescant heat? No way! Dr Zak 16:11, 12 April 2006 (UTC)

It's not my term, it's Alexander (2005)'s; in particular, Table 6 from which the figures were taken, is entitled "Total volatility...." How about "is volatilized in air"? --James S. 18:06, 12 April 2006 (UTC)

You can have high volatility or low volatity, but only a compound with high volatility can be described with volatile the adjective. Volatize, the verb, does mean go to a gas, but still does not implay that a compound is volatile. Olin 18:58, 12 April 2006 (UTC)

We are discussing the second paragraph of the introduction, the one that begins At temperatures below the burning temperature of uranium in air .., right? Well, that whole section is a collection of non-sequiturs and what information is in there should go elsewhere. To elaborate:

  • To say that UO3 is volatile by oxidation of U3O8 is somewhat beside the point. A chemist would observe that the uranium oxides are unstable towards oxygen loss at high temperatures and would say that UO3 loses oxygen at elevated temperatures to form U3O8 and that (gaseous) UO3 is in equilibrium with solid U3O8. Indeed, the article says already so. If one really wants to focus on uranium toxicity to state that some species of uranium evaporates one might state that "uranium is volatilized as UO3 at high temperatures". This should go into a section on toxicity and environmental effects
  • Saying that the "enthalpy of formation of UO3 is much larger than any other uranium oxide gas" is pretty meaningless. Of course its enthalpy of formation is the highest of all uranium oxides, every extra oxygen adds to ΔH! The value of ΔH says precisely nothing about stability, what matters is if there are any thermodynamically more stable compounds that the compounds may decompose to under the given conditions. Hint: ΔG is temperature-dependent, especially so when gases are involved. Besides: are there any other "uranium oxide gases"? To the best of my knowledge, UO3 is the only volatile uranium oxide.
  • If "only one peer-reviewed report has reported evidence of uranium trioxide in combustion products" why is it so important to mention this in the lead paragraph? One should say so if formation of uranium trioxide under such conditions is a common misconception that needs debunking.

Comments are appreciated. I would like to drop the paragraph altogether, for the reasons stated above. Dr Zak 19:42, 12 April 2006 (UTC)

I was more focussed the word "volatile"; I just don't think it's an accurate term. "Appreciable" or "nonnegligible vapor pressure at high temperatures" I can deal with, just not volatile. I do appreciate your comments about enthalpy (see the discussion above). Olin 22:55, 12 April 2006 (UTC)

Isotope fractionation

The lithium salts sold have the same problem (most of it ends up in hydrogenbombs). Also the carbon from organic sources differ from that of inorganic sources. Is the effect big enough to mention in the table?--Stone 06:48, 13 April 2006 (UTC)

The "government health warning" is taken from the IUPAC table of atomic weights. They do distinguish between natural variation (footnote 2) and man-made isotopic enrichment (footnote 3). Lithium is mentioned as an extra-pathologic case (footnote 4). There is a couple of other elements (hydrogen, boron, a few more). I guess we should leave the warning in - IUPAC points out that the isotopic ratio of commercial samples may not be the same as the one found in geologic specimens, and UO3 that ends up on the market may well have passed through an enrichment plant, after all uranium is mined mostly for use in nuclear reactors. Dr Zak 14:03, 13 April 2006 (UTC)

source

(Gabelnick, Reedy, Chasanov, 1970) they published a lot 1970-1973 I think its from 1972 or 1973.--Stone 11:58, 13 April 2006 (UTC)

Gabelnic SD, Reedy GT, Chasanov MG (1974). "Infrared-Spectra and Structure of some Matrix-Isolated Lanthanide and Actinide Oxides". Journal Chemical Physics 60: 1167-1171. 

  • Gabelnic SD, Reedy GT, Chasanov MG (1973). "Infrared-Spectra of Matrix-Isolated Uranium Oxides 2. Spectral Interpretation and Structure of UO3". Journal Chemical Physics 59: 6397-6404. 
  • Gabelnic SD, Reedy GT, Chasanov MG (1973). "Infrared-Spectra of Matrix-Isolated Uranium Oxides 1. Stretching Region". Journal Chemical Physics 58: 4468-4475. 
  • Gabelnic SD, Reedy GT, Chasanov MG (1973). "Infrared-Spectra of Matrix-Isolated Uranium Oxides Vapor Species". Chemical Physics Letters 19: 90-93. 

--Stone 16:51, 13 April 2006 (UTC)

It's paper 2 in the series. My mistake. The citation in the References section is correct. Dr Zak 17:42, 13 April 2006 (UTC)

UO3 as combustion product of uranium

The introduction states that

only one peer-reviewed report has reported evidence of uranium trioxide in combustion products.

Further down it says that

some have suggested that UO3(g) is not a combustion product of uranium combustion in air, even though U3O8 comprises 75% of the particulate combustion product

That sounds really inconsistent. If there is only one report stating that the compound is present then the text should read "most have suggested that UO3 is not a combustion product". Also, what exactly does that 1978 report say exactly about the composition of the oxide species that result from uranium combustion? What are the missing 25 %? When UO3 is not present (or present only in trace amounts) I do question the value of either statement in an article on uranium trioxide. The more suitable place is the article on uranium. Dr Zak 17:10, 13 April 2006 (UTC)

The other 25% is UO2 particulates. The point I'm trying to get at, since nobody will let me say outright that UO3(g) is a combustion product, is that there are no sources, after months of asking, which suggest that it is not, and no alternative hypothesis to explain the U3O8(s) other than condensation and decomposition of UO3(g). Moreover, the inhalation of UO3(g) explains the uranyl contamination of cellular nuculi which is not accompanied by detectable depleted UO2 from lung contamination in urine isotope studies. But that apparently amounts (just barely) to original research, so I can ony say it here on talk. However, the statements as they are at present in the article, and similar statements in other articles about particulate dispersal studies not considering UO3(g), are directly supported by sources, so they can be included. --James S. 19:58, 13 April 2006 (UTC)

Hah. That UO2 makes up the rest of the dust from DU firings is what one's chemical intuition tells one and what Le Châtelier's principle predicts. At higher temperatures endothermic processes (e.g. oxygen loss) are favored. Gmelin mentions the fact in passing, here where it states that "U3O8 shows in its equilibrium state a noticeable oxygen deficiency already at 500 to 700 °C, which persists even after slow cooling in air". (Emphasis mine.) If no great amount of UO3 is formed during uranium combustion then it shouldn't be mentioned. Also, if U3O8 is more soluble than UO2 it would be taken up by cells preferentially, and don't forget that in the presence of water and air the uranyl ion is very stable. The report that you cite does not mention gas at all, only very fine particulate matter that enters deep into the lungs.

Nothing of what you cite supports the notion that UO3 is formted in any mount during uranium combustion, and that's why the article on uranium trioxide should not mention it as a combustion product. Dr Zak 20:45, 13 April 2006 (UTC)

I just browsed through the Salbu paper. It gives as products from DU projectiles UO2, U3O8 and uranyl carbonate (presumably from weathering of freshly formed particles). Nowhere is Uranium trioxide conclusively detected. Dr Zak 21:00, 13 April 2006 (UTC)

In Fig. 4 in the Salbu paper the powder diffraction patterns of UO3 and of some DU dust particles are compared. Note how the distinctive peak near d=3.4 of UO3 is absent in the DU samples. Salbu notes that herself, saying "the fit to UO3 ... data suffers from uncertainties". Also note the conclusions, where only U2O5 and uranyl salts are mentioned, not UO3. Dr Zak 14:18, 14 April 2006 (UTC)

On the contrary, the second paragraph of the conclusions section, as well as the abstract, states: "environmental or health impact assessments for areas affected by DU munitions should take into account the presence of respiratory ... UO3 particles." --James S. 16:08, 14 April 2006 (UTC)

The experimental section gives the spectra which is less specific than the conclusion!--Stone 18:22, 14 April 2006 (UTC)

The first paragraph of the Conclusions section states that DU oxide dust collected from tanks contains UO2 and U3O8. Oxide dust collected from the remains of that fire in an ammo storage depot the authors state is in oxidation state +5 to +6, and most similar to solid uranyl compounds. The authors say specifically (on page 10) "most of the investigated particles ... could be attributed to solid uranyl compounds (e.g. UO2(CO3))" and state that the powder pattern won't really fit UO3.
My guess (original research and only permitted on the talk page) is that the U3O8 originally formed has weathered to uranyl compounds. Note that the Battelle report explicitly says that freshly formed particles are especially prone to weathering.
Please show me where the authors actually FIND UO3 as opposed to just talking about it. Dr Zak 18:36, 14 April 2006 (UTC)
They show the XANES spectra of UO3, and the spectra of the collected samples, and except for one line, they match. Why else would they be talking about it?
Anyway, this is an absurd double standard: I am not allowed to say that UO3(g) is a combustion product, because it condenses and decomposes into U3O8, but when the U3O8 in turn weathers to UO3, then that's not a combustion product either?
And anyway, you're deleting far more than what would be justified by this objection, even if it were valid:
  • Why delete the burning temperature?
  • Why delete the volatility, fully supported by Alexander (2005)?
  • The sections you deleted refer to "evidence of" UO3, not confirmation of their detection, and make it clear that the report is in only one source.
  • Why delete the partial pressures of UO3(g)?
  • Why delete the proportions of particulate combustion products?
This is simply a subterfuge so that you can claim that you discussed your objections before deleting -- something very much broader than you are objecting to. Reverting. --James S. 18:57, 14 April 2006 (UTC)

To answer your questions:

  • the burning temperature of uranium is a property of uranium. Go to uranium.
  • The fact that U3O8 is volatilized at UO3 at high temperatures is already mentioned in the article and not that spectacular a property that it must absolutely go into the introduction
  • If an assertion (like UO3 being formed from DU ammo) is neither supported by facts nor widely believed then that is good reason to removed it as irrelevant
  • The partial pressures of UO3 in the gas phase are still in the article
  • Take the combustion products of DU elsewhere. UO3 is not a combustion product. Go elsewhere. They do not belong here.

The XANES spectra aren't really diagnostic here - they at most tell the oxidation state and the interpretation is often doubtful. My very respected thesis advisor has described the method as "occupational therapy for physicists". On the other hand, the powder diffraction pattern of a compound is really diagnostic and powder patterns are excellent for fingerprinting. If a compound is present is will show ALL lines, all of them. If just one is missing and the rest fits the compound is not there. So the data in the Selbu paper do not support the assertion that UO3 is present in the combustion products.

Please stop sidetracking the issue. If you want uranium combustion mentioned in the article on UO3 give reliable sources that support the assertion that UO3 is a combustion product. Otherwise it has to go per WP:V. Dr Zak 19:22, 14 April 2006 (UTC)

Whether you like it or not, that UO3 is formed from DU ammo is supported by the cited source, and implied by the fact that there is no other explanation for the quantity of U3O8 produced, other than condensation and decomposition. You have no sources supporting your assertion that "UO3 is not a combustion product" and Salbu clearly contradicts that. I don't care what your very respected thesis advisor describes as occupational therapy; your interpretation of the powder patterns is at odds with the published authority. You can complain that Salbu's data do not support her assertions to the reviewers who approved her paper, but you can not use your personal opinion as the basis for removing source-supported research. Reverting. --James S. 20:37, 14 April 2006 (UTC)

SALBU:In a few particles, U showed a pattern similar to U2O5 (Fig. 4b), while most of the investigated particles originated from the fire could be attributed to solid uranyl compounds (e.g., UO2(CO3)), although the fit to UO3 literature XRD data suffers from uncertainties (Fig. 4c). Makes clear what you can think of the clear and undoubted finding of uranium trioxide. The author is at best not sure at worst wrong.--Stone 22:35, 14 April 2006 (UTC)

WHERE IS UO3 IN THE COMBUSTION? I CANT FIND IT!!!!!!!!!!!!!!!--Stone 22:35, 14 April 2006 (UTC)

Prior to formation of yellowcake, and after its weathering. Ha! Before and after. Those who have claimed that UO3 is not a combustion product are boxed in. It's a question of truth over time: is the sequence yes, no, yes equivalent to yes, for events disjoint from the time of "no"? The answer is yes; uranium trioxide is completely a combustion product of uranium burning in air. --James S. 06:34, 15 April 2006 (UTC)
Seems you are advocating original research and at the same time illustrating why it is not allowed here. Wikipedia isn't a record of truth, it is what people believe to be truth. To cut your words short, even you put down where Salbu claim to conclusively detect the compound. They are talking about it, sure, but nowhere do they claim to detect it.
To address the chemical question that you mention: Salbu et al are not concerned with the processes that formed the dust particles, and after weathering uranium is present in the cation (UO2)2+. Dr Zak 23:33, 15 April 2006 (UTC)
There is nothing wrong with discussing original research here on talk, but the sections you have been removing from the article are all source supported, even if their implication, which you don't like, is not directly.
Salby et al. specifically state that UO3 inhalation should be considered. You misrepresent my edits when you claim that I "put down where Salbu claim to conclusively detect the compound" -- I wrote that they showed evidence of it, which is not the ame thing.
Do you still maintain that there is no uranyl ion in uranium trioxide? --James S. 20:28, 16 April 2006 (UTC)
Salbu mention UO3 a couple of times. However nowhere in the paper do they claim to detect the compound, and the evidence is against it. Not even you denies that - if there was conclusive evidence in favor you would have pointed out where it is. Dr Zak 14:58, 17 April 2006 (UTC)
Stating that "health impact assessments for areas affected by DU munitions should take into account the presence of respiratory ... UO3 particles" in both the abstract and the conclusion of the paper obviously indicates that the authors did believe there was conclusive proof of it. Just because you disagree with the interpretation of a single line on a spectrograph doesn't mean that you can delete all mention of the paper. I am reverting and I will continue to revert this deletion without further discussion here. --James S. 17:04, 17 April 2006 (UTC)
No, there is no uranyl ion present in UO3. There is no need for that to make the compound bioavailable (and dangerous to health). Our own Wikipedia states that UO3 dissolves in acid to yield UO2+, the uranyl cation, which then causes all sorts of mischief in the body. UO3 isn't the toxic species, it's a solid at room temparature. Its dissolution products are. One would guess that U3O8 (with an avarage oxidation state of 5 2/3) dissolves readily as well, especially freshly prepared finely divided samples. This is actually important: the higher the oxidation state the more bioavailable is the uranium compound.
And I guess that is what Selbu et al. are saying: they are using UO3 as a synonym for uranium species with a high bioavailability. Dr Zak 16:54, 17 April 2006 (UTC)
Saying there is no uranyl ion in UO3 is like saying there is no sodium ion in table salt. UO3 is uranyl oxide. Just because the ion is bound instead of dissasociated doesn't mean that the ion doesn't exist. It is true that aerosol U3O8 dissolves quickly, but as you have pointed out, this article is about uranium trioxide, and whether you like it or not the peer-reviewed Salbu et al. paper indicates evidence for UO3. --James S. 17:04, 17 April 2006 (UTC)
James, can you please put the finger on the evidence FOR UO3? I think the XANES spectra are inconclusive (average oxidation state 5.5 +/- 0.5, the authors say), and the powder pattern is strong evidence AGAINST. Dr Zak 17:16, 17 April 2006 (UTC)
The powder pattern is only evidence against the collected samples being pure UO3, and is consistent with the fact that they are composed of mixed oxides, as I suspect you already know well. The fact that U3O8 is found implicates the condensation and decomposition of UO3. We have been over all this before. I will continue to revert your unjustified, unsupported deletions, and I will not respond to you again until you apologize for your personal attacks: calling me a crank in edit summaries and comparing me to a fence post in the arbitration workshop. --James S. 17:54, 17 April 2006 (UTC)
(restart indentation). I have stated before that the Salbu paper is not concerned with the mechanism of combustion, only with the analysis of the products. Drawing inferences and stating things someone does not say if original research and banned here.
I said that before, and precisely because you refuse to reply you are called a fencepost. Dr Zak 20:07, 17 April 2006 (UTC)
As the subject is coming up again, I don't really like the latest source that says that UO3 is a combustion product of uranium. The publication cited is an army manual which is concerned with the use of DU on the battlefield, which in turn cites two army technical reports. To those the composition of the product is a secondary issue, their aim is to protect the users (the soldiers and future occupiers of the conquered territory) from health hazards. We already have a publication whose authors have reluctantly ruled out the presence of UO3 in DU combustion products. If nothign more concrete appears I'll remove the section in a few days. Dr Zak 18:14, 23 April 2006 (UTC)
Which source's "authors have reluctantly ruled out the presence of UO3 in DU combustion products"??? --James S. 18:46, 23 April 2006 (UTC)
Salbu et al. They can't find it even though they've been fishing for it yet urge to take suitable precautions. Dr Zak 20:19, 23 April 2006 (UTC)
Because they know, following Ackermann, Wilson, etc., that it decomposes to U3O8 upon condensation? And more importantly, "... take into account the presence of respiratory ... UO3 particles" is not ruling out their presence, reluctantly or otherwise; just the opposite. --James S. 20:55, 23 April 2006 (UTC)
No. They state that the particles found in the ammunition dump fire were most likely uranyl carbonate. If they in the face of this result urge precaution against something else, something that they couldn't find, it means that they found this result unexpected. Dr Zak 21:25, 23 April 2006 (UTC)
Uranyl oxide weathers to uranyl carbonate. Where else could it come from? --James S. 22:53, 23 April 2006 (UTC)
From freshly formed U3O8. Two of three uranium atoms are already in oxidation state +6, one is +5 and will oxidize to uranyl ion in the presence of water. Remember: uranium compounds do end up as uranyl salts in the presence of air and water. Dr Zak 02:42, 24 April 2006 (UTC)
I know that under oidizing conditions it is possible to convert UO2 to UO2++ compounds. I am thinking about the work of people such as Shoesmith. James might want to read about the Rocky Flats soil, a lot of spectrscopy work has been done to try and work out what form the Pu in the soil is in.[6]Cadmium

Remove the pic of hypothetical UO3 molecule

Featuring a picture of the infamous T-shaped UO3 highlights a species that is at best of controversial and more likely simply unimportant. Otherwise, should we be depicting the structures of all species generated by vaporization of solid oxides, solid halides, solid sulfides.... In other words, depicting such a species violates the NPOV in a scientific sense, since it suggests significance where there is none. One solution would be to create a "gaseous UO3" article that could become the locus for the controversy and allow those that just want to understand this poor ole oxide to discuss its solid-state properties.Smokefoot 22:17, 18 April 2006 (UTC)

As there is nothing special about the structure - the true minimum is likely trigonal planar and the "T-shaped structure" is something of an experimental artefact I heartily support this change.
Not that there is anything wrong with gas phase structures of oxides etcetera per se. If there is anything peculiar about any structure by all means point it out! Dr Zak 22:33, 18 April 2006 (UTC)
By the way, what "controversy" over UO3(g) do you mean? POV forking is discouraged, it just creates lots of little soapboxes for cranks to stand on that are impossible to police. I do not even believe there is a controversy at all, no credible evidence for gaseous UO3 being a combustion product of uranium has been produced. Dr Zak 22:40, 18 April 2006 (UTC)
If anyone finds themself writing a gaseous uranium trioxide article, I have made 2D and 3D images of both a T-shaped and a trigonal planar UO3 molecule, available on one of my userpages. Cheers. --Ben 23:12, 18 April 2006 (UTC).

Dr. Alexander's opinion

I recently sent the message below to Dr. Carl Alexander, who has been active in uranium physical chemistry for almost half a century, and is a famous scientist in other fields, participating in the Voyager space probe program and currently working on missile defense systems. He replied thusly:

-------- Forwarded Message --------
Subject:     RE: uranium combustion produces how much UO3(g)?
Date:     Thu, 20 Apr 2006 16:31:15 -0400
From:     Alexander, Carl A (alexandc at BATTELLE dot ORG)
To:     James Salsman (james at bovik dot org)

I would expect that gaseous UO3 would be the major product of
such “burning” in air. I consulted and reviewed Wendell Wilson’s
paper prior to publication so I am familiar with it although I
haven’t seen it in a good many years. I don’t know the health hazard
of gaseous UO3 but chemically it behaves a lot like WO3 and WO3 is
certainly a bad actor. Gaseous UO3 is quite stable and you are
correct that upon condensing it would likely become U3O8.

-----Original Message-----
From: James Salsman
Sent: Thursday, April 20, 2006 4:11 PM
To: Alexander, Carl A
Subject: uranium combustion produces how much UO3(g)?

Dear Dr. Alexander: 

Thank you for publishing your paper, "Volatilization of urania
under strongly oxidizing conditions," which I recently read
with great interest.  I have been trying to determine the amount
of UO3(g) produced from combustion of uranium.  I have recently
been corresponding with the famous coordination chemist Prof.
Simon Cotton, who suggested that I contact you with my question. 

Depleted uranium munitions such as those used for 20-30 mm and
larger antitank ordnance are incendiary due to the pyrophoric
nature of uranium.  More than 30% of such bullets' uranium metal
burns in air when they are fired against hard targets.  It
seems that the burning temperature should usually be above 2500
Kelvin, because the bullets are described as fragmenting into a
spray of tiny particles as they pass through armor.  (Mouradian
and Baker (1963) "Burning Temperatures of Uranium and Zirconium
in Air," Nuclear Science and Engineering, vol. 15, pp. 388-394.)

Inhalation of uranium combustion fumes is suspected in major
illnesses reported in veterans and civilians of the February,
1991 Gulf War.  However, none of the people responsible for
determining the health hazards has yet reported measurements of
the gas vapors produced, only the particulate aerosol fumes,
which are described as 25% UO2 and 75% U3O8 (Gilchrist R.L.,
et al. (1979) "Characterization of Airborne Uranium from Test
Firings of XM774 Ammunition," Technical report no. PNL-2944
Richland, WA: Battelle Pacific Northwest Laboratory.) Based on
the thermodynamic formation energy data I have been able to
find (H. Wanner and I. Forest, eds. (2004) Chemical
Thermodynamics of Uranium (Paris: OECD and French Nuclear
Energy Agency) http://www.nea.fr/html/dbtdb/pubs/uranium.pdf
-- see table V.4 on p. 98) it seems like production of UO3
would be much more likely than UO2 or U3O8.  Moreover,
condensation and subsequent decomposition of UO3(g) can
explain the U3O8(s) product:  see Wilson, W.B. (1961)
"High-Pressure High-Temperature Investigation of the
Uranium-Oxygen System," Journal of Inorganic Nuclear Chemistry,
vol. 19, pp. 212-222, at the bottom of p. 213.

If there are substantial amounts of UO3(g) produced in uranium
fires, that could explain discrepancies in both troop exposure
patterns and the solubility and resulting pharmokinetics of
those exposed.  Most people have been assuming that only the
particulate aerosols present any exposure risk.  But those
settle out of the atmosphere much more quickly than gas, which
is absorbed immediately if inhaled in contrast to the great
length of time which it takes for UO2 and U3O8 particles to
dissolve in the lungs.  Urine tests intended to determine
exposure which measure the ratio of uranium 238 and 235
isotopes assume that only particulate aerosols and not quickly
absorbed and dissolving gas have been encountered.  Those urine
tests have been negative for exposure in patients who have the
symptoms of uranyl poisoning.

Can you please help shed any light on the amount of UO3(g)
produced when uranium burns in air?  Thank you.

Sincerely,
James Salsman

So, is it fair to say that "Uranium chemist Dr. Carl Alexander expects that gaseous UO3 would be the major product of uranium combustion in air"? --James S. 16:47, 22 April 2006 (UTC)

It's a genuinely irrelevant statement. Everyone knows that U3O8(s) is in equilibrium with UO3(g). If you wish to use this to back up your pet theory of "UO3(g) from DU ammo hangs around and causes ill health" you would have to find something that supports that assertion. Dr Zak 03:02, 23 April 2006 (UTC)

Also note that Dr Alexander doesn't say a word about UO3 gas in the atmosphere in his reply. I guess he is just being polite. Dr Zak 03:04, 23 April 2006 (UTC)

Are you and I even reading the same text? I suppose I should ask him what he means by "quite stable." --James S. 05:18, 23 April 2006 (UTC)
While I am from the camp which considers that it is unlikely that UO3 gas will last for sufficent time that a human could breath it in, my reading of the letter sent to James does to me include the sentance that UO3 gas is "stable". The great problem is that everything is stable to some degree, the term stable in chemistry is only a relative term. While acetylene is an endothermic compound, it is still stable at 20 oC and 1 Atm. I have a very pressing question for you James, Why do you think that the gas/solid question has any effect on the legal aspects of a chemical in warfare ? As I understand it quite a few chemical warfare agents (whose use is strictly regulated or outlawed by international law) are liquids or solids in the form which they are dispersed and used in. Eg mustard and VX are both heavy oils.Cadmium
It's not so much the legal aspects, but uranyl oxide gas production could explain the exposure of trops and civilians with related symptoms who were too far away to have been exposed to the quickly settling aerosols. As Philip Baird Shearer has recently explained in detail with his very impressive edits to Depleted uranium#Legal status in weapons, simply producing poison gas isn't illegal if that isn't the weapon's main purpose. And, given that the toxic effects take weeks to several years to show up, I'll be last to argue that the toxic hazard is intentional, even though plenty of DU opponents do argue that. I'm interested in a way to explain the exposures in Basrah, because aerosols can't, and a way to explain why people with obvious uranyl poisoning don't have DU isotope ratios in their urine from particulates slowly disolving in their lungs. UO3(g) production explains both.. --James S. 18:42, 23 April 2006 (UTC)
I read "stable" as "stable under the conditions that it is formed at", that is at white incandescence. If the solid/gas question is to be discussed any further it should be pointed out that filtering out fine aerosols with a gas mask is much more difficult that filtering a gas. During WW I the Germans would use diphenylarsinous chloride in combination with chlorine gas or phosgene. "Blaukreuz" is the keyword to look for. Blaukreuz would pass through the charcoal filter, being a very fine aerosol and cause irritation in the throat. The victim would then vomit into his mask, tear it off and receive a lethal dose of chlorine. Reading early-twenties arsenic chemistry originating from Porton Down is SCARY. Dr Zak 17:29, 23 April 2006 (UTC)
Yuck! Anyway, as for "stable," I'll ask. --James S. 18:42, 23 April 2006 (UTC)
That vomit gas and chlorine combination does sound rather irksome !Cadmium

Removal of POV tag

POV dispute templates should not be removed unless both sides of the dispute agree that it is resolved. --James S. 16:31, 27 April 2006 (UTC)

It would be useful if you could demonstrate that there is a genuine neutrality dispute, for example by pointing out tendentious or misinterpreted sources or things omitted in order to put forward a certain viewpoint. At the moment the dispute (if it exists at all, in fact myself I'd say the issues have been resolved on the talk page) looks like something of a content dispute. You know, tagging an article to support a certain idea raises neutrality issues, too. Dr Zak 17:50, 27 April 2006 (UTC)
I think you know what the dispute is -- the facts you have been deleting are all sourced, they are all relevant to the topic, and they all have very notable health and safety implications. If you look at your edit history, it is clear that most of your efforts on Wikipedia have been devoted to removing just this information, with a few other minor edits to other articles. You have no objections to the peer-reviewed and other sources other than your opinions, for example, that Salbu et al. detected weathering products from uranium trioxide -- and so they have no edivence of it. That just doesn't make sense, and I think your pattern of editing, and that of others who have argued forcefully against the inclusion of the disputed material, is clearly indicative of trying to push a point of view. It's not an accuracy dispute, because you're deleting, not including unsourced statements. --James S. 18:29, 27 April 2006 (UTC)
Ever heard of the ad hominem fallacy? Dr Zak 18:50, 27 April 2006 (UTC)
People have biases, facts do not. It is very appropriate to point to your personal behavior as evidence of point of view pushing. --James S. 18:54, 27 April 2006 (UTC)
Can we get back to the supposed POV dispute, which is about the suggestion that UO3 gas is a combustion product of uranium, pretty please? You see, I'm not sure that there even is a dispute. We have been through Busby, who has been shown a fraud, then there was Salbu et al, whose results you misinterpreted and now we have an army field manual to support the idea. That source fails, too, being a field manual it isn't exactly as credible as a paper. Dr Zak 19:13, 27 April 2006 (UTC)
Facts can be biased in the way they are presented. It is not the case that science consists of cold, hard, unbreakable truths. There are often many seemingly contradictory observations made of a particular phenomenon, which are only adequately understood in the context of much more sophisticated models. From what I have seen occurring on this talk page and within the article, I feel that the following chain of events happens repeatedly:
  • A piece of information exists, such as the statement "Aerial oxidation of any uranium compound eventually results in the formation of a uranyl compound" (Simon Cotton, page 127, Lanthanides and actinides - Macmillan (1991))
  • James says: "Simon Cotton, perhaps the world's foremost expert on heavy metal chemistry, states that uranyl compounds are the result of aerial oxidation of any uranium compounds. Do you have any reasons that Professor Cotton is mistaken?" Further on, he adds: "Again, you ignore Cotton (1991), and you have no sources at all which claim that uranyl compounds are not always the result of oxidation of uranium compounds in air". Just because no sources citing X are produced, it does not follow that X is false. The lack of sources citing X is not proof that X is untrue. (In this case, X stands for: uranyl compounds can be formed without the aerial oxidation of uranium compounds).
  • Either way, it's not the facts per se that are the problem. It is taking a source and extrapolating from it to reach unfounded conclusions that is problematic to many contributors to this article. I am sorry to single out James in this example, as I have seen many others, myself included, making this type of logical error.
  • Of itself, this type of error is not hugely significant. But when it becomes the lynchpin in a dispute, its significance increases. Cotton's quote should not be used to make conclusions from other sources' research. It should not be said that the existence of uranyl compounds in a human body proves the person in question was exposed to burning uranium. As an example of why this kind of conclusion is not logical, there may be another mechanism by which a uranyl compound can find itself in a human. Uranium or its non-uranyl compounds could be inhaled, ingested or otherwise incorporated in the body, and then oxidised in vivo to a uranyl compound or ion. I'm not saying this is true, I have no evidence to suggest it is, I simply invented this mechanism as a purely figurative example.
  • As editors of this article, which focuses on a sensitive issue to many, we must be careful not to write things which do not follow logically from our cited sources. If there is a single error, however minor, in our reporting of a source's conclusions, other editors and readers of Wikipedia may feel that original research is being undertaken. It is of paramount importance to avoid this situation, given the depth of feeling surrounding the issue of depleted uranium and Gulf War Syndrome.
-Ben 20:58, 27 April 2006 (UTC)

What kind of "extrapolation" is Nrcprm2026 being accused of here? The unreverted portion of the article already supports a T-shaped gas molecule. The other statements about depleted uranium weapons and gas from them are in the sources, not extrapolated from them. Why are people so sensitive about this issue? 12.178.40.29 20:51, 29 April 2006 (UTC)

Personally, I'm not sensitive about these issues. I just want to understand the chemistry involved, and provide diagrams and 3D models where possible to aid understanding. For others, these issues are very important, either because they suffer from Gulf War Syndrome, they know people who do, or they are campaigning against the use of toxic or radioactive substances in general.
The extrapolation I refer to is this:
  • Simon Cotton writes that aerial oxidation of any uranium compound eventually results in the formation of a uranyl compound
  • James takes this to mean that any uranyl compound must therefore have been formed by aerial oxidation of uranium or a uranium compound
  • This does not follow logically
I am at pains to point out that I am not making a personal attack on James here - I am neutral (or uninvolved) as far as the issues are concerned, I simply want to improve the article with images, and to make sure that the article is factually correct.
In fact, I will take this opportunity to say thanks to James for all the work he has put in to this article. James, I know many of your contributions have been controversial, and I do not feel strongly about DU and its compounds like you do, but you have provided many useful and interesting references, you have encouraged debate about the science on this talk page, and you have made available to all us editors a vast amount of information as scanned PDFs on your Bovik website.
And Cadmium, thank you on behalf of the readers and editors of this article for providing beautiful and clear images of the polymorphs of solid UO3, and ensuring they are used and referred to correctly.
--Ben 23:35, 29 April 2006 (UTC).
Thanks for your comments about the polymorphs, to be truthful I have to admit that James did help with getting the labels right on the diagrams. I feel that I should now add some more content (source supported : James's term) on UO3. I have increased the size of the section of solid state chemistry of UO3 by adding details of how two of the different forms are made using different synthetic methods. I also want to increase the size of the section of the insertion of cations into the lattice. Cadmium