Sciencemadness Discussion Board

Radiochemistry

careysub - 7-8-2014 at 12:58

This may turn into a Donnybrook, but I want to open a reasoned, factual discussion of amateur radiochemistry - on the same level of other discussions on this website.

This site has many discussions of handling dangerous materials - such as the long running thread on the preparation of gram-scale amounts of phosphorus
(mostly by processes that distill vapor), for a material that causes severe poisoning in amounts of 15 mg, and with a lethal dose of 50 mg.

Other popular threads include discussions of shaped charges, in fact there is an entire forum devoted to preparing high explosives (Energetic Materials).

Although special, unusual hazards are called out on occasion when an ill-advised preparation procedure is described, notable absent are comments that seek to shut down the entire discussion.

With the mention of radioactivity on the other hand, then such comments pop up with some regularity. [I can cite examples if others insist.]

I am interested in at least discussing, if not performing, replication of some of the key processes of the early nuclear era: isolation of the more stable daughter nuclides from uranium ore, the separation of americium and preparation for display, etc.

Due the availablity of materials, if for no other reason, these types of experiments are limited to working with microcurie amounts - amounts where the hazards of exposure are confined to the hazards of actual ingestion.

Under the NRC General License for the use of nuclear materials quantities of not more than 5 microcuries are generally exempted from filing for a specific license, i.e. are normally legal to possess. The only substantial hazard from sources of this magnitude is ingestion.

For example the skin dose for 1 microcurie of Ra-226 (i.e if you applied it to your skin, not recommended, and easily avoidable) is 20 mRem an hour. You would have to leave it on your skin for 40 hours to raise an average annual exposure to radiation (350 mRem) to the average annual exposure that people living in Denver receive every year (1200 mRem), and that is only in the region of the skin affected.

For Am-241 the skin dose is only 1 mRem, and if it were in a test tube the exposure would be near zero (low energy gammas are too weak to penetrate).

I submit we should be able to discuss microcurie level experiments without evoking cries of great alarm.

Discussion of actual safety precautions is desired and indeed, welcomed.








[Edited on 7-8-2014 by careysub]

careysub - 7-8-2014 at 13:22

To start off any discussion that may follow, it is obviously necessary to have some way of detecting radiation to follow what is happening with any manipulation since you cannot see the material.

Designs for a variety of simple and inexpensive ionization detectors are readily available, one that in particular looks well suited is the "polonium pen" described here:
http://www.techlib.com/science/ion.html

Brain&Force - 7-8-2014 at 13:36

Quote: Originally posted by careysub  
For Am-241 the skin dose is only 1 mRem, and if it were in a test tube the exposure would be zero (gammas are too weak to penetrate).


You need lead sheets to stop gamma rays. Test tubes won't cut it.

I would be interested, but what kind of projects do you have in mind (specifically, with what elements/sources?)

Texium - 7-8-2014 at 13:54

Perhaps he meant alphas? Am-241 is an alpha emitter after all, that would have made a lot more sense.

careysub - 7-8-2014 at 14:21

Quote: Originally posted by Brain&Force  
Quote: Originally posted by careysub  
For Am-241 the skin dose is only 1 mRem, and if it were in a test tube the exposure would be zero (gammas are too weak to penetrate).


You need lead sheets to stop gamma rays. Test tubes won't cut it.


Lets see if I "misestimated" from taking a quick look at penetration energy graph.

Am-241 produces gammas of three energies 14, 16 and 60 keV. The mass attentuation coefficient for borosilicate at these energies are ~5.2 cm^2/g for the first two, and 0.24 cm^2/g for the third. You can get thick-walled test tubes with a 2 mm wall, and the density is 2.2, for a mass-thickness of 0.44. I calculate that 90% of the lower energy gamma flux would be blocked, but only 10% of the most energetic. A roughly similar amount (~10%) of the higher energy would be blocked by the layer of fluid, if the material is in solution.

So 80% or so of the 60 keV gammas (produced by only about 1/3 of the decays) would escape the tube wall.

So you are right, only partial protection (but more than you thought I expect). It represents only about 0.3% of the total decay energy.

But lead is not required, 1/8" of stainless steel would block 95% of the escaping 60 keV gammas.

http://physics.nist.gov/PhysRefData/XrayMassCoef/ComTab/pyre...
Quote:
I would be interested, but what kind of projects do you have in mind (specifically, with what elements/sources?)


Replicating the separation of radium from pitchblende, performed by Mme. Curie for example.

Replicating the separation of a transuranic (americium) from uranium and other elements by the bismuth phosphate process used by the Manhattan project.

Preparing a phosphor/americium or a phosphor/radium mixture for display.

[Edited on 7-8-2014 by careysub]

[Edited on 7-8-2014 by careysub]

[Edited on 7-8-2014 by careysub]

[Edited on 7-8-2014 by careysub]

vmelkon - 7-8-2014 at 15:08

Quote: Originally posted by careysub  
I submit we should be able to discuss microcurie level experiments without evoking cries of great alarm.


I don't see why you can't discuss it.

Have you done any of these experiments?
Do you want to discuss actual experiments or talk about possible experiments.

Personally, I have only done Am-241 + Al foil.

IrC - 7-8-2014 at 18:55

Quote: Originally posted by careysub  
I submit we should be able to discuss microcurie level experiments without evoking cries of great alarm.


I have no doubt on many sites this hyper hysteria is what you are used to encountering. However here I think you will find many who are very interested in the science, myself being one of them.

I submit you should begin by posting a working plan on solvent extraction of Uranium from it's ores. Mostly because I am tired of waiting for United Nuclear to actually write the page on it they have promised to do for many years yet have not.

I suspect you are Carey Sublette, and have forgotten more on the subject than most will ever know. I read your pages "Nuclear Weapons Frequently Asked Questions" many years ago. Very good read.

http://nuclearweaponarchive.org/Nwfaq/Nwfaq.zip

Nice to have someone here very well versed on the subject. We have a few threads on building detection devices also. You will find people here are more into the science of things and less into the hysteria so prevalent most places online.

By the way Carey welcome to SCM. You are no doubt one of the most knowledgeable people on the subject of nuclear energy ever to post on this site (if not indeed the most knowledgeable) . I hope you stay for a long time. Someone with your knowledge is a great benefit to this site.

neptunium - 7-8-2014 at 21:10

when the litterature mentioned "on contact with the skin" they dont think you are actually going to put a source of radium or Americium in your pocket and walk arround with it for a day or two...

they mean the dust that we cannot see the radioactive powder generated by the chemical treatment of radio active element in chemical reactions. the short lengh particle like alpha and beta (or low energy gamma)
become a real threat to the health if not removed from the skin or the inside of the human body,

having said that, the fear of contamination and death by exposure when it comes to milicurie is vastly exagerated and simple common sense and protection eliminate most of the risk.

it is in fact less dangerous to react 5milicu of Am241 than 5 ml of PCl3 ! i think we will all agree to that!

even with large amount of uranium ore , the danger of exposure to lethal radiation is often exagerated .

we are always reminded of Marie Curie brutal fate ,lets not forget that after years of manipulations of enormous amount of Radium it still took over a decade to develope leucemia. and no one knew what to look for at the time!

again common sense and normal laboratory safety habit inhibit most of the risk when it comes to radiological hazard or not.

in conclusion, as for explosives/toxic chemicals i would sudjest the same approach....

do the research ( know the danger)
low quantities and
always wear safety gears

that kept me out of trouble so far...

now what do you want to do ?





the chemistry of radio isotope ( in particular trans uranium group) is fascinating and very well deserve a chapter in this site !

[Edited on 8-8-2014 by neptunium]

Texium - 7-8-2014 at 21:59

Quote: Originally posted by neptunium  

the chemistry of radio isotope ( in particular trans uranium group) is fascinating and very well deserve a chapter in this site !
Indeed it does... maybe even its own subforum if it really takes off.
I'd love to do some (careful) dabbling with radioactive experiments. I wanted to buy a cheap ionization smoke detector at the hardware store the other day to dissect, but my dad wouldn't let me because he thought it was a "waste of a perfectly good smoke detector" :mad: which surprised me because normally he lets me buy whatever I want for my experiments.

neptunium - 8-8-2014 at 05:30

hhaa yeah i remember those fustrating days of not being able to afford much and dreaming about having my own lab....

patience my friend! we all get old to soon...

Marvin - 8-8-2014 at 10:13

I am a fan of the nuclear weapons archive. That aside I remember a biological description of radiation from a tv program about 20 years ago Gammas were likened to air pellets, sailing through matter and scattering without a lot of damage. I don't remember what betas were likened to but alpha particles were bowling balls, they'd knock everything over if they could get through the dead layer of the skin. Inhalation or ingestion removes this block and the alphas blast everything to bits with their high specific ionisation. Uranium ore is of the order 1uCi per gram of uranium, but that comes with up to the same amount of polonium, the same amount of long half life radium and all the daughters in between and down to lead in essentially invisible amounts.

If you use a Geiger counter to follow the chemistry you can be fooled. Boiling a uranium salt in slightly alkaline solution (a transition metal co-precipitant helps) produces a highly active precipitate and a 'dead' solution. The ppt is actually short half life thorium and the solution regains it's activity over days/weeks.

All wet chemistry contaminates every surface around it and is absorbed to some extent by the chemist. Most nasties discussed in this forum are rendered safe by natural processes in human acceptable time-scales, phosphorus, cyanide, even metallic mercury is excreted by the body pretty well given a non-contaminated environment. Radium is quickly laid down in bones and stays their for life (it's or yours) with all it's daughters as an alpha emitter.

I know I have a tendency to be preachy and patronising but I think a lot of the members of this forum are young and high spirited and would happily try things that could seriously affect their life span. SM has had at least 1 death and RS has had at least two. The radioactive boy scout did end up with radiation poisoning and I think doing radiochemistry at home is like a child stirring dog shit with a stick.

neptunium - 8-8-2014 at 12:07

Marvin is right , we have to consider the youngest home scientist reading these posts.
I have a degree in physics and decontamination in nuclear power plant where i worked in a lab for school 15 years ago. and although i would love to do some radiochemistry at home i am not willing to contaminate
my family or anyone else`s.
the danger cannot and should not be underestimated although low the consequences of a small mistake could be dire.
things always happen in the lab sometimes benine sometimes bad . dealing with the clean up is one thing, dealing with a doctor telling you about your rare cancer is another

IrC - 8-8-2014 at 12:28

So I guess the first thought careysub had was right.

"Marvin is right , we have to consider the youngest home scientist reading these posts."

I agree first off close down the energetics forum and lock it from all access since I have no doubt far more young and upcoming scientists have been harmed dabbling with explosives by orders of magnitude than radio-chemistry.

"dealing with a doctor telling you about your rare cancer is another"

I never noticed every thread in Organics being given this warning even though I have no doubt statistically cancers have been caused by exposure to chemicals in greater numbers than radiation. We all know many if not most organic solvents are carcinogenic.

Why is it the two of you are not busy posting warnings to stay away in all other sub forums on this site? I implore you to show the statistics on harm caused by this topic as compared with all other topics in amateur science.

neptunium - 10-8-2014 at 00:32

the point was to not encourage younger maybe foolish readers.
the science is always good and i strongly beleive in self responsabilities
and consequences . god knows i did my share of foolish experiments! we all did..
Also firm beleiver in free expression so no need to shut down energetics and radio chemistry.
However , i am reluctant encouraging spoon feeding and detailled procedures to inexperienced
beginers or bored sunday teens.

careysub - 10-8-2014 at 13:00

I had been working on this position paper on radiophobia for a couple of days, and I think that it is good to post it to provide a safety context:

On Chemophobia and Radiophobia

The ScienceMadness Wikia has an article entitled "Chemophobia", which begins: "Chemophobia is an irrational fear of chemicals, particularly synthetic chemical...".

What does it mean for a fear to be irrational? What objective test will distinguish between one such, and a rational fear? Or is it all a matter of subjective name-calling?


There is an objective way of determining whether a risk is being perceived in an irrational way: if it is being accorded a level of concern that is inconsistent with the viewers other views about risks of similar magnitudes. If risks that are measurably larger are being accepted with equanimity, while substantially smaller ones are regarded with alarm, then this is a "phobic" attitude.

One cannot live life without taking risks. Even making a quick trip to a nearby store exposes one to the possibility of death in a traffic accident. Currently the risk of death in the U.S. per mile travelled in a car is about one fatality per 50 million miles travelled. A five mile round trip to the store then amounts to accepting a 1-in-ten million risk of traffic death in exchange for the convenience of buying what ever it is you wanted to buy. Very few people give this a first thought, much less a second.

When dealing with fatal hazards it is also important to consider the concept of "number of years of life lost". A fatal traffic accident will kill you today, and the remaining years of your life will be lost. If you are 30, we might estimate this loss at 50 years. On the other hand the risk of exposure to a weak chemical carcinogen might exposure you a risk of death from the exposure of 1-in-ten million (like the 5 mile car trip), but that death would occur decades later so the loss of life-years would be greatly reduced.

With chemophobia fear is largely driven by sheer misinformation - believing risks are far larger than they really are, often any risks are immeasurably small if they exist at all.

A parallel phenomenon exists with regards to radiation, which affects a fair number of the ScienceMadness community. In this case potentially severe hazards from handling chemicals are often taken in stride, while risks from very low-level radiation exposure that are immeasurably small give calls of alarm.

The accepted point of view on this forum with regards to chemical safety is that experiments in general can be conducted "safely" (with a small chance of adverse result to the individual) if proper procedures are followed. Not infrequently there is discussion of proper safety procedures, and sometimes a proposed experiment is nixed as being excessively dangerous without extraordinary precautions, but generally experiments are discussed without explicit reference to safety procedures, because otherwise all discussions would be vastly expanded with the same sort of boilerplate warnings that occupy the first ten pages of every product manual these days.

In the 13 page long lead salts preparation thread there is only one poster referring to the severe chronic lead toxicity problem. OSHA recommends a lead body burden limit of only 400 micrograms per kg, or 28 mg in a 70 kg adult. Many of the experiments discussed on the thread were processing amounts tens of thousands of times larger than that, so that an accidental absorption of only 0.01% of the material being handled would expose you at a level regarded as unsafe.

By contrast discussions about handling radioactive materials with permissible levels of radiation, levels low enough that the NRC feels that they do not need any sort of license to possess or handle, often evoke cries of generalized alarm.

As a specific example, in a recent thread I mentioned that it was possible to make a striking glowing display specimen of americium for an element collection by dissolving it (0.9 microcuries) from its gold smoke detector carrier (requiring aqua regia), and deposit on zinc sulfide for enclosure in a sealed tube for display.

Whereupon another poster, ignoring the hazard of the aqua regia, declared it irresponsible to suggest that such a thing could be done.

But consider the contrast in risks.

What is the worst thing that could happen if aqua regia is mishandled? It could cause agonizing burns, permanent disfigurement and blindness, and if you were so daft as to swallow it, a fatal result from internal injury could not be excluded.

What is the worst thing that could happen if 0.9 microcuries of Am-241 is mishandled?

The worst case would be to swallow it all. And what then?

First off the exposure would within OSHA limits of acceptable workplace exposure if averaged over a period of 15 months, so it would not be out of line with accepted workplace safety standards.

Second, it would impossible to detect any adverse affect on the individual from the ingestion, ever. The amount ingested is less than the amount of natural radioactive potassium in your body (1.2 microcuries). The only hazard from the exposure would be to increase the lifetime cancer risk of the individual from about 30% (the chance everyone takes), by an incremental amount of 0.03% to 30.03% if factored over a 50 year period (older people would have less risk exposure). If one eventually did get cancer, there is only a one in one thousand chance that swallowing the americium was responsible.

But the same lab safety procedures than keep you from swallowing lead, or the aqua regia, will be just as effective in keeping you from swallowing americium. If we felt that is was achievable to limit lead intake to less than 0.01% of the material you were handling in the lab, then those procedures would do the same with the heavy metal americium, limiting actual exposure to something like 0.09 nanocuries (3.7 Bequerel), or less than 1/10 of the radiation in a 1/4 tsp serving of Nu Salt salt substitute.


[Edited on 10-8-2014 by careysub]

[Edited on 10-8-2014 by careysub]

careysub - 10-8-2014 at 13:51

Quote: Originally posted by Marvin  
... Inhalation or ingestion removes this block and the alphas blast everything to bits with their high specific ionisation....

If you use a Geiger counter to follow the chemistry you can be fooled. Boiling a uranium salt in slightly alkaline solution (a transition metal co-precipitant helps) produces a highly active precipitate and a 'dead' solution. The ppt is actually short half life thorium and the solution regains it's activity over days/weeks.


Depends on what you mean by "fooled".

The counter is giving you an accurate assessment of the radiation present. If you know your nuclear chemistry there is nothing "fooling" going on - freshly separated natural uranium will reach equilibrium with the 24 day Th-234 and Pa-234 (1.5 minutes) and its net by 150% radioactivity, to match any other "old" sample of separated uranium. Meanwhile that active precipitate will decay way over several months.
Quote:
All wet chemistry contaminates every surface around it and is absorbed to some extent by the chemist.


What fraction of the chemicals you handle normally get absorbed into your body would you estimate?

One advantage of radioactive materials is that surface contamination is very easy to detect. Not so chemical poisons.
Quote:
Most nasties discussed in this forum are rendered safe by natural processes in human acceptable time-scales, phosphorus, cyanide, even metallic mercury is excreted by the body pretty well given a non-contaminated environment.


Metallic mercury (as in mercury vapor) passes easily through the blood-brain barrier, and the estimated retention time there is 25 years.

Lead? Not excreted - it accumulates. The permissible body burden is only 24 mg.

Maybe we shouldn't discuss handling mercury or lead in our forums?
Quote:
Radium is quickly laid down in bones and stays their for life (it's or yours) with all it's daughters as an alpha emitter.


True. You don't want to absorb it, just like you don't want to absorb metallic mercury or lead. Appropriate safety precautions should be taken.

But if you are working with the amount permitted without license by the NRC, 5 microcuries, and successfully avoid absorbing more than a tiny portion (which I believe would be typical for properly conducted set of chemical operations), then you are talking about very small life-time risks.
Quote:
I know I have a tendency to be preachy and patronising but I think a lot of the members of this forum are young and high spirited and would happily try things that could seriously affect their life span.


It is impossible for any amount of radioactive material complying with the NRC general license to do this, no matter how it was mishandled. The worst case for the maximum amount would be something like a 1-in-1000 chance of contracting cancer late in life.
Quote:
SM has had at least 1 death and RS has had at least two.


I would guess from energetic materials, which are discussed quite extensively and freely here, yes?

Are you calling for a shut-down of that forum?
Quote:
The radioactive boy scout did end up with radiation poisoning


No, David Hahn has never shown any adverse symptoms from his radiation exposure. Nor is it expected that he ever will.
Quote:
and I think doing radiochemistry at home is like a child stirring dog shit with a stick.


An odd comparison. I have never known any harm to come from that activity.

[Edited on 10-8-2014 by careysub]

[Edited on 10-8-2014 by careysub]

careysub - 10-8-2014 at 13:57

Quote: Originally posted by vmelkon  
Quote: Originally posted by careysub  
I submit we should be able to discuss microcurie level experiments without evoking cries of great alarm.


I don't see why you can't discuss it.

Have you done any of these experiments?
Do you want to discuss actual experiments or talk about possible experiments.

Personally, I have only done Am-241 + Al foil.


No, haven't done any of these experiments yet.

I am considering plans for doing some over the next few years, and I intend to discuss those plans to solicit comment in advance of actually carrying them out.

Discussing safety procedures, and safe quantities, are an important topic to be covered.

careysub - 10-8-2014 at 14:07

Quote: Originally posted by zts16  
Quote: Originally posted by neptunium  

the chemistry of radio isotope ( in particular trans uranium group) is fascinating and very well deserve a chapter in this site !
Indeed it does... maybe even its own subforum if it really takes off.
I'd love to do some (careful) dabbling with radioactive experiments. I wanted to buy a cheap ionization smoke detector at the hardware store the other day to dissect, but my dad wouldn't let me because he thought it was a "waste of a perfectly good smoke detector" :mad: which surprised me because normally he lets me buy whatever I want for my experiments.


The first thing you should do is make a radiation detector in advance of trying anything else with radiation.

Detecting radiation with a cloud chamber is really cool (especially since it uses dry ice).

A smoke detector source is way too strong for this, a cloud chamber source needs to be about 0.01 microcuries not 1.0 microcuries (it would just make the chamber a "fog chamber").

You can do a safe radiation demo if you get a smoke detector source and a zinc sulfide coated scintillation screen like this one:
http://www.ebay.com/itm/ZnS-Ag-scintillation-screen-spinthar...

You can also make a gold-foil electroscope and show how a smoke detector source makes it lose its charge immediately. A sample of uranium ore works well too.

Making a spinthariscope is pretty neat also.

Then consider getting a Geiger counter kit (there are several available), or making an ionization chamber detector.

Radiophobia and Chemophobia

careysub - 12-8-2014 at 13:35

The high alarum some have raised at the very mention of manipulating radioactive materials however small the amount represents an extreme inconsistency in how they themselves ordinarily evaluate risk, even in the case of radioactivity (more on this below).

Recall that the quantity of radiation currently under discussion is at the level of several microcuries or less, amounts typically permitted under the NRC general license without registration. At these levels even gross mishandling of the material (the worst case is ingesting all of it in soluble form) is swamped by ordinary daily exposures. The resulting radiation exposure hazard from ingesting the one microcurie of Am-241 in one smoke detector is 15 millirem a year, similar in risk to an extra 375 millirem all at once if you are 25 or so (similar to a lower one if you are older).

For comparison the exposure from natural radioisotopes found in everyone's body (K-40, C-14) is 40 millirem a year. Flying three coast-to-coast round trips a year exposes one to 15 millirem. The average total annual exposure from natural sources is about 350 millirems, and the variation in background radiation in different parts of the U.S. varies from a low of 250 millirems to a high of 1500 millirems. A 15 millirem additional annual exposure amounts to about 1% of the extra hazard of living in parts of New England or Colorado.

How many people out there regularly (or ever) consult a map like this one of the US background radiation field?
http://www.goldismoney2.com/attachment.php?attachmentid=7223...

Travelling from a low radiation area to a high radiation area constitutes an added exposure as large as 100 millirems a month. If you are from Florida and spend four months in some parts of Colorado your added cancer risk from that trip is as large as "eating the smoke detector". Where are the stern admonitions about the peril of visiting the Rocky Mountain State?

If you don't care about small incremental radiation exposures at any other time in your life, why is it now so alarming that the mere discussion of it in the context of chemistry is considered intolerable?

Consider the practice of ordinary chemistry. There are many terribly dangerous activties involved, that can easily cause injury, severe property destruction, or even death. Activities like using fire.

Seriously - has anyone here ever thought that the use of an alcohol lamp or other burner, even by a young person epxerimenting with chemistry, is an intolerable hazard?

In one year in the U.S. there are nearly half a million house fires that require fire department attention, kill 2500 people, injur some 15,000 (severely enough to be reported). I will bet that a large portion of the readers here have at least one burn scar, however small, somewhere on their body. This represents a real, and painful, physical injury that is disfiguring, if only slightly.

Use of an exposed flame in an environment where flammable chemicals are present is an extreme potential hazard. But I submit, the attitude toward this risk is: follow appropriate safety procedures, don't do something stupid, and you will be fine. No problem. But the worst case potential accident is often dire indeed.

Consider the hazard represented by the chemicals typically used in experiments.

The worst case scenario with microcurie amounts of radioactive substances is the extreme one of consuming all of the sample. And the most apocalyptic result is a very small theoretical ("theoretical" since it is projected from theory and can never be detected in practice) cancer risk increase decades in the future.

Let us use this same standard for risk-assessment with most any of the experiments described on this site - how many of the experiments here would produce no detectable adverse effect if you ate all of the reactants? A large share of them would kill you outright. This represents a risk factor something like four orders of magnitude greater, yet such potential risks normally pass here without any comment. Again proper procedure protects against accident it is believed, and no one is upset.

And consider this: chemistry allows you to make highly toxic substances when before you have none. A 16 year old who frequented this site apparently died because he made phosgene and poisoned himself a few years ago.

Radiochemistry is restricted to the quantity of radionuclides you start with. You cannot make more (only nuclear physics can do that), and NRC regulations and the sheer cost make it all but impossible to obtain genuinely hazardous amounts.

If microcurie chemical manipulations are deemed too hazardous to discuss on this site, I submit that consistent behavior would require complete shut-down of the entire site, not just the "explosives group". Chemistry could hurt someone! Think of the children! Better to forbid it be discussed!

The opposition to responsible radiochemical investigation is radiophobia, the precise parallel of chemophobia, and every bit as extreme in mischaracterizing the risks. This is "Science Madness", not "Reefer Madness".

Microchemistry

careysub - 12-8-2014 at 13:38

One attractive feature of pursuing amateur radiochemistry is the boost it gives to a very interesting area of chemical technique: microchemistry. I understand this sort of a cutting edge thing - being adopted by universities around the world to improve the quality of chemical education (you can contemplate more elaborate procedures with tiny amounts), and reduce costs, and environmental impact.

Here is a an article detailing this state-of-the-art field of chemistry:
http://actinide.lbl.gov/gtsc/seminars/2012/PuLab_LifeInterna...

Yes, it is a 1946 Life magazine article detailing the advances in microchemistry created by the Manhattan Project. This technique was well established 70 years ago! Unfortunately those nifty little necked "microcones" used by Seaborg and company do not seem to be made anymore. Cone-shaped microwell plates seem to be what people use.

(Microchemistry actually dates from the century before - it was founded by Francois-Vincent Raspail in the 1830s).

Handling chemicals present in microgram amounts calls for equipment scaled down by a factor of 1000 from what you might use when treating milligrams or grams. A "large" flask is not 1000 mL, but 1 mL and so on. Tiny amounts of solvents and other reagents are used. This has the advantage of making very expensive reagents, or ones that can ony be made in low yield, practical.

More exotic lab conditions can be obtained more easily:

Want to use a hyper-corrosive solution? Pressing a bit of platinum foil into a conical microwell cavity will give you a platinum reaction chamber.

Want to test a reaction at a very high temperature? A sample can be set-up for heating in an oxyhydrogen torch, or an arc furnace on a benchtop.

If you are interested in the chemistry itself, instead of performing production processes (nothing wrong with that - not a thing), then microchemistry has many attractions and advantages.

MrHomeScientist - 13-8-2014 at 06:41

Quote: Originally posted by careysub  
If you are from Florida and spend four months in some parts of Colorado your added cancer risk from that trip is as large as "eating the smoke detector".

That's exactly my situation! Except I'll only be visiting for a week, so my risk would be 1/16 of a smoke detector :)
Quote:
One attractive feature of pursuing amateur radiochemistry is the boost it gives to a very interesting area of chemical technique: microchemistry.

I'm not a big fan of microchemistry for the amateur chemist, personally. The amounts discussed are so miniscule that you really have no idea what you're working with without fancy equipment to detect your products. Plus I think a lot of amateurs (myself included, probably) don't have the skill or equipment necessary to manipulate such tiny amounts. When your entire stock of a chemical is contained in a single drop, a shaky hand could ruin the whole experiment. And what of that last bit of solution that stays in the pipette? I guess my point is that any losses are magnified extremely in microchemistry - 0.01mL adhered to a beaker means nothing when working with liters, but is significant when you only have microliters. Finally, when your experiment is done you have a barely visible product, which to me doesn't seem worth the effort. Perhaps I have "microphobia," though.

More on topic with radiochemistry, I definitely see what you mean. Even I am quite wary of radioactive substances - too much so, it seems. Your reasoned arguments have really given me pause and made me think more about how I assess risk. I too have been waiting for forever for United Nuclear to post Part 2 of their uranium extraction. It would be great to see some work in this area here on the board.

Texium - 13-8-2014 at 07:10

Quote: Originally posted by MrHomeScientist  
Quote:
One attractive feature of pursuing amateur radiochemistry is the boost it gives to a very interesting area of chemical technique: microchemistry.
I'm not a big fan of microchemistry for the amateur chemist, personally. The amounts discussed are so miniscule that you really have no idea what you're working with without fancy equipment to detect your products. Plus I think a lot of amateurs (myself included, probably) don't have the skill or equipment necessary to manipulate such tiny amounts. When your entire stock of a chemical is contained in a single drop, a shaky hand could ruin the whole experiment. And what of that last bit of solution that stays in the pipette? I guess my point is that any losses are magnified extremely in microchemistry - 0.01mL adhered to a beaker means nothing when working with liters, but is significant when you only have microliters. Finally, when your experiment is done you have a barely visible product, which to me doesn't seem worth the effort. Perhaps I have "microphobia," though.
I agree with you about that. I've tried doing really small scale experiments before (not even true micro) and it got very confusing ("I think it reacted...?"). In the end, I got what I thought was a good product, but I had so little of it that if I tested to ensure its purity (or at least its identity), I would have lost most of it, and then I wouldn't have it anymore after working so hard for it. I'm all for macro scale experiments, test tube scale at least. Last night I read through this thread that was a debate about microscale vs macroscale and their place in both professional labs and amateur labs.

careysub - 13-8-2014 at 10:31

Quote: Originally posted by MrHomeScientist  

...
I'm not a big fan of microchemistry for the amateur chemist, personally. The amounts discussed are so miniscule that you really have no idea what you're working with without fancy equipment to detect your products. Plus I think a lot of amateurs (myself included, probably) don't have the skill or equipment necessary to manipulate such tiny amounts. When your entire stock of a chemical is contained in a single drop, a shaky hand could ruin the whole experiment. And what of that last bit of solution that stays in the pipette? I guess my point is that any losses are magnified extremely in microchemistry - 0.01mL adhered to a beaker means nothing when working with liters, but is significant when you only have microliters. Finally, when your experiment is done you have a barely visible product, which to me doesn't seem worth the effort. Perhaps I have "microphobia," though.


Thanks!

Perhaps we could declare a middle ground: "mini chemistry"?

The fact is, with practical radiochemistry you are working with a radioactive tracer - something that can only be detected by its radiation emissions and while you could dissolve it in a liter, a milliliter would do as well.

The only way you can work with bulk, macroscopic material is to work with natural radionuclides of ancient cosmic origin (uranium*, thorium*, and potassium) or to have your radionuclide embedded in a carrier (as with radium and barium).

Reasonably priced scales with a sensitivity down to one milligram are readily available, beakers and test tubes with volumes of 2-3 mL. Although it seems hard to find a flask less than 10 mL I'm not sure there is need on any. Volume measuring precision is limited to about 100 microliters (using a graduated syringe) or 40 (maybe 25?) microliters using a calibrated dropper, but you can weigh solutions with 1 microliter accuracy. Working with masses on the order of 10-100 mg, and fluid volumes of 0.1 to 1 mL seems to allow acceptable precision with readily available equipment. Certainly it is small scale if not what is considered true "micro".

Even here you're raw materials are running $10/g and up.

[Edited on 13-8-2014 by careysub]

careysub - 13-8-2014 at 10:57

Quote: Originally posted by MrHomeScientist  

I too have been waiting for forever for United Nuclear to post Part 2 of their uranium extraction. It would be great to see some work in this area here on the board.


You must be referring to this page (which I had not seen until now):
http://www.unitednuclear.com/extract.htm

Since he is selling uranium ore for around $3/g (as best I can determine) the 300 g he starts with in the demo would cost around $1000 if bought from him.

The best deal I know of on uranium is ore is 1 kg of German pitchblende for $175 from Shannon and Sons.

I can start working on a process flow chart, but it will be theoretical for a good while, and my focus is on extracting and separating all of the radionuclides to the extent that is possible, not just extracting the uranium.

I'll be publishing a series of essays over time (see, I've already started), the initial focus will be on detectors and calibration sources without which nothing much can be done (except maybe extracting uranium).

MrHomeScientist - 13-8-2014 at 11:26

That's good stuff, carysub. The page you linked is indeed what we were talking about. He does occasionally get in 'bulk' uranium ore, or larger pieces of high activity ore, but is frequently sold out. I imagine that would be cheaper per gram, but your point is well taken.

I think "mini chemistry" is certainly acceptable, especially when dealing with expensive reagents. In fact pretty soon I'm going to try my hand at purifying natural placer gold via aqua regia, which necessarily will be with under 1g of gold as a starting material. That's pretty mini, and I didn't really even think about that until just now!

Something else I'd love to see, to know if it's practical, is to reduce the AmO2 found in smoke detector sources to elemental Am. I'm using one such pellet as my sample for my element collection, but it would be much better as the element rather than a compound :)

careysub - 13-8-2014 at 12:10

Quote: Originally posted by MrHomeScientist  
...
Something else I'd love to see, to know if it's practical, is to reduce the AmO2 found in smoke detector sources to elemental Am. I'm using one such pellet as my sample for my element collection, but it would be much better as the element rather than a compound :)


You will have a problem with trying to exhibit an element in visible form when you only have 0.25 micrograms of it (the amount in a contemporary smoke detector).

This is what 20 micrograms of a salt of Americium looks like:
http://www.vanderkrogt.net/elements/element.php?num=95

I don't think preparing a visible sample (without high magnification) is really feasible.

My suggestion is to deposit the americium in a phosphor and have an americium display specimen similar to the "radium dial" radium specimen most people use in their collection.

To get to 20 micrograms, and duplicate the Seaborg sample, you could obtain 80 smoke detectors; shelling out ~$400 if bought new. (This sort of thing starts falling afoul of the NRC general license, since it limits how much of something you can have in one place.)

You could also round up a Pyrotronics F5 series detector made in the early 1970s. These had an astounding 80 microcuries (20 micrograms) in one detector. Since these were made 40 years ago 10% of the AM-241 has decayed to Np-237, so these old detectors now contain 2 micrograms of neptunium, the only accessible source of this I know.

neptunium - 13-8-2014 at 17:16

well of course ! the goal is not to see the element! but to prove its presence! hence a spectrometer!
my thread on radio isotope identification is about just that!

http://www.sciencemadness.org/talk/viewthread.php?tid=27963

being able to chemicaly separate those elements and follow them with the spectrometer (gamma and/or alpha)
is what radiochemistry is about! accumulating massive amount of highly active isotope is just asking for all kinds of trouble! and unless you have access to a dump truck full of ore , impossible!

careysub - 14-8-2014 at 06:33

Quote: Originally posted by neptunium  
well of course ! the goal is not to see the element! but to prove its presence! hence a spectrometer!
my thread on radio isotope identification is about just that!

http://www.sciencemadness.org/talk/viewthread.php?tid=27963

being able to chemicaly separate those elements and follow them with the spectrometer (gamma and/or alpha)
is what radiochemistry is about! accumulating massive amount of highly active isotope is just asking for all kinds of trouble! and unless you have access to a dump truck full of ore , impossible!


Exactly!

And a gamma-ray spectrometer? Wow!

I have still to get together a "click counter" - looking around for the best kits for this purpose.

The United Nuclear uranium ore work-up page appears to be all about just extracting uranium. If you want that he is already selling pure metal at a reasonable price ($10/g in 10+ gram allotments - I don't currently know a cheaper source).

This is a waste of good ore: which also contains equilibrium amounts of Ra-226 (also a Rn-222 generator), Ac-227 (also a Fr-227 generator), Pa-231, and Pb-210 (Po-210 generator) all which are stable enough to separate and store for decades, and none of which can you buy. Also there are a mixture of active thorium isotopes. Being able separate and identify at least these nuclides (the old mysterious "radiums" of the early literature) makes this an interesting challenge (and adds five elements to your element collection). Simple uranium extractions would discard them all.

(Also his procedure is suitable for carnotite ore - for which I can identify no "reasonably" priced source, the only half-affordable source I can find has pitchblende/uraninite.)



[Edited on 14-8-2014 by careysub]

neptunium - 14-8-2014 at 08:49

i agree, however Uranium is NOT that expansive! i REFUSE to pay $10 per gram of a metal
worth $30 per pound!
When nature can provide you with free rocks as much as you can carry!
everybody seems to want it when all we really need is a cheap radiation detector and a location to go prospecting..
now i know not everybody can afford to take time off and travel accross the country and roam the Utah desert for rocks but charging $10 a gram (or more! way more!!!) is ridiculous!
as for collecting samples of the element i would be content with a chunk of uranium ore insteat of Radium ,Actinium and Co...
who would even try to get Astatine??? the best i would do is point at the gamma spectrum the peak label At210
(half life 8hours!)
thats the beauty of spectrometry! we dont need grams !! a few thousand atoms is enough!

Marvin - 14-8-2014 at 09:45

careysub, I am having some difficulty in locating the part of the NRC General licence that permits the manipulation of microcurie amounts of radionuclides in solution by members of the public. Could you provide this to put our minds at rest?

careysub - 14-8-2014 at 19:31

Quote: Originally posted by Marvin  
careysub, I am having some difficulty in locating the part of the NRC General licence that permits the manipulation of microcurie amounts of radionuclides in solution by members of the public. Could you provide this to put our minds at rest?


I was waiting to see when this issue would be raised on this thread, after getting past the unreasoned fears of working with small amounts of radiation.

You want to find specific permission written into Federal regulation? Sorry, no can do.

If you wish to conduct radiochemical investigations you will have to join the rest of the hobby chemists in skirting regulation by not causing anyone any problems, or you can apply for an NRC license citing educational or other worthy goals.

My citations of the NRC general license has been to show that the quantities of radioactive materials that it permits people to obtain and possess are not seriously hazardous (and to point out that you can actually obtain and possess them).

There is a parallel with the Energetic Material forum where, I submit, few posting there can produce an ATF license to manufacture explosives, or evidence that their projects are sanctioned by the military, FBI, DHS, or the state and local police and Fire Marshal.

Did you know that any explosive device is defined in Federal law as a "weapon of mass destruction" (see "18 U.S. Code § 2332a - Use of weapons of mass destruction")?

How many home chemists invite the Fire Marshal in for a regular inspection?

How many posting on the ever popular phosphorus manufacturing thread have applied for, and received a license from the DEA which is required for everyone manufacturing a List 1 chemical?

Here is an interesting excerpt from NRC regulations:

"40.4 Definitions.
...
Source Material means: (1) Uranium or thorium, or any combination thereof, in any physical or chemical form or (2) ores which contain by weight one-twentieth of one percent (0.05%) or more of: (i) Uranium, (ii) thorium or (iii) any combination thereof. Source material does not include special nuclear material.
...

40.13 Unimportant quantities of source material.
...
(b) Any person is exempt from the regulations in this part and from the requirements for a license set forth in section 62 of the act to the extent that such person receives, possesses, uses, or transfers unrefined and unprocessed ore containing source material; provided, that, except as authorized in a specific license, such person shall not refine or process such ore."

Notice that it is legal to obtain and possess unprocessed ore - but it is specifically forbidden that you process it.

Now look at the United Nuclear page showing ore processing:
http://www.unitednuclear.com/extract.htm

This is unusual, most of what we might contemplate doing with radioisotopes is not *specifically* forbidden. But this experiment directly contravenes explicit Federal regulations. We have definite documentation of the violation. It is a commercial enterprise, which is pretty much what the NRC regulates. Yet no ax has falled on United Nuclear from the NRC. (Its earlier legal brouhaha was from the Consumer Products Safety Commission who objected to it selling chemicals for fireworks.)

Here is another item to consider, the NRC's last annual report for the Office of Investigations, its enforcement arm:
http://pbadupws.nrc.gov/docs/ML1405/ML14058A899.pdf
In 2013 they opened a grand total of 149 cases, roughly 1/3 of them employee discrimination cases, of the rest they seem to be pretty much split between reactor licensing investigations, and licensee false statement investigations.

Unlike the DEA, perhaps, which is known to work with local law enforcement to raid suspected one man meth labs, it does not look like the NRC puts any resources into investigating what people with general license materials are doing with them.

Also consider the resource of the two agencies. The materials safety part of the NRC not committed to reactor operations is $86 million in FY15 budget and is focused on regulating its thousands of licensees (hundreds of occupational site inspections are performed). The DEA budget is about $3 billion and pretty much all of its resources are in criminal law enforcement, there is simply no parallel in regulation or investigation of private individuals by the NRC compared to the DEA.

I submit the NRC does not appear to have any people out busting folks for fiddling with their smoke detectors.

[Edited on 15-8-2014 by careysub]

careysub - 14-8-2014 at 19:58

Quote: Originally posted by neptunium  
i agree, however Uranium is NOT that expansive! i REFUSE to pay $10 per gram of a metal
worth $30 per pound!
When nature can provide you with free rocks as much as you can carry!
everybody seems to want it when all we really need is a cheap radiation detector and a location to go prospecting..
now i know not everybody can afford to take time off and travel accross the country and roam the Utah desert for rocks but charging $10 a gram (or more! way more!!!) is ridiculous!
...


US producers get paid about $50/lb (as element, not oxide).

I'm not sure you can find anything but low grades of uranium ore on the surface in the U.S. are any more. Uranium is still heavily mined, and the "low hanging fruit" was dug up long ago. Surface deposits were prospected for very intensely during the 1950s and early 1960s.

If all you can find is 0.1% grade, then even at $10/g your ore would only be worth $10/kg and you have to dig up several hundred kg to finance your prospecting expeditions just to break even.

[Edited on 15-8-2014 by careysub]

neptunium - 14-8-2014 at 22:46

nevertheless...there is a few closely garded secrets out there...

careysub - 19-8-2014 at 11:09

Quote: Originally posted by careysub  
...
I submit the NRC does not appear to have any people out busting folks for fiddling with their smoke detectors.


I just reread "The Radioactive Boy Scout" (an account that makes ones eyes roll fairly often, it tends to florid exaggeration) - and it confirms my take on the issue of Federal regulation of radioisotopes.

The NRC regulates NRC licensees (businesses and government agencies) that's it, no one else. The NRC did not get involved in any way in the David Hahn case. The only Federal agency that looks into private radioactive holdings/issues is the EPA, and only when they are brought to the EPA's attention.

It would be impossible with low microcurie amounts of radioactive material to create a situation where the EPA would care about what you doing, even if you chose to bring it to their attention.

[The David Hahn case was a bizarre anomaly, first off he had spent years buying and stealing and conning radioactive materials; and the situation turned into the Federal case that it did because of the way he brought his project to the attention of authorities - getting arrested with radioactive materials in his car, then spooking them into activating the state (and in turn Federal) emergency response systems.]

[Edited on 19-8-2014 by careysub]

IrC - 19-8-2014 at 13:25

On page two and thus far no real chemistry has been discussed on the subject. Based upon the majority of posts in these two pages thus far, maybe the thread should be moved to 'Legal and Societal Issues '?

careysub - 19-8-2014 at 14:52

Patience, I am just getting started on this.

Establishing a "manifesto" reviewing the safety and legal risks seemed necessary to kick this off, and reactions posted here (and off-line) support that judgment.

What I would like to see is for a new forum called "Radiochemistry" be created, and the various threads about uranium, thorium, radioactivity, geiger counters, nuclear history (and this one) be moved there.

IrC - 19-8-2014 at 16:50

Quote: Originally posted by careysub  
Patience, I am just getting started on this.

Establishing a "manifesto" reviewing the safety and legal risks seemed necessary to kick this off, and reactions posted here (and off-line) support that judgment.

What I would like to see is for a new forum called "Radiochemistry" be created, and the various threads about uranium, thorium, radioactivity, geiger counters, nuclear history (and this one) be moved there.


Have you looked at any of these threads?

http://www.sciencemadness.org/talk/viewthread.php?tid=25882

http://www.sciencemadness.org/talk/viewthread.php?tid=27963

http://www.sciencemadness.org/talk/viewthread.php?tid=29654

http://www.sciencemadness.org/talk/viewthread.php?tid=28985

http://www.sciencemadness.org/talk/viewthread.php?tid=28582

careysub - 19-8-2014 at 17:02

Yep, those are some of the key threads to which I refer.

I would like to see them moved to a new radiochemistry sub-forum.

IrC - 19-8-2014 at 18:15

U2U Polverone and see if he will do that. Would be easier than searching since some of the threads are fairly well buried in pages of forums.

MrHomeScientist - 20-8-2014 at 06:15

Quote: Originally posted by careysub  
Now look at the United Nuclear page showing ore processing:
http://www.unitednuclear.com/extract.htm

This is unusual, most of what we might contemplate doing with radioisotopes is not *specifically* forbidden. But this experiment directly contravenes explicit Federal regulations. We have definite documentation of the violation. It is a commercial enterprise, which is pretty much what the NRC regulates. Yet no ax has falled on United Nuclear from the NRC. (Its earlier legal brouhaha was from the Consumer Products Safety Commission who objected to it selling chemicals for fireworks.)[Edited on 15-8-2014 by careysub]

Something to note is that their primary customer is the DoD, so they likely have the necessary licenses to store and handle "large" quantities of radioactive material.

Great thread so far. I eagerly await the chemistry!

chornedsnorkack - 21-8-2014 at 02:27

So... is U poisonous after all?

Is Th?

Would Pu-244 be detectably poisonous?

neptunium - 21-8-2014 at 05:04

uranium and thorium like any heavy metal are toxic in milligram to gram quantity, Plutonium is a different story. micrograms are usually enough to have a toxic effect. so yes absolutely detectable.

[Edited on 21-8-2014 by neptunium]

careysub - 21-8-2014 at 07:00

Quote: Originally posted by chornedsnorkack  
So... is U poisonous after all?

Is Th?

Would Pu-244 be detectably poisonous?


The tolerable oral intake of soluble uranium is based on its chemical toxicity and is the same as lead for adults: 50 micrograms/kg a day (about 100 mg a year for a 70 kg adult).

Thorium appears to be much less toxic, its tolerable level is set by its radioactivity which is also lower than uranium's, so when I run the numbers it comes out to a surprising 6000 mg a year.

chornedsnorkack - 21-8-2014 at 07:28

Quote: Originally posted by neptunium  
uranium and thorium like any heavy metal are toxic in milligram to gram quantity,


No such thing as "any heavy metal" - lead is poisonous, bismuth by contrast far less so.

Seems like thorium also is much less dangerous. But thanks careysub for reminding that it is impossible to define toxic amount without knowing the biological lifetime and other such features of the substance....

neptunium - 21-8-2014 at 13:51

Quote: Originally posted by chornedsnorkack  


No such thing as "any heavy metal" - lead is poisonous, bismuth by contrast far less so.


all things considered .... of course

The Volatile Chemist - 21-8-2014 at 14:52

Sometimes (According to Wikipedia's element classifications page) Heavy metal refers to poisonous metals/metal ions. Anyways, is David Hahn's 'work' documented is his book mostly correct?

Careysub, if you have knowledge in radioactivity (and related) your contribution to the Sciencemadness Wiki would be much appreciated!

I prefer test tube size if I'm to go 'small'. Personally a "radiochemistry" subforum would be nice, but I don't think necessary. It seems rather limited.

Texium - 21-8-2014 at 15:08

Quote: Originally posted by The Volatile Chemist  
Personally a "radiochemistry" subforum would be nice, but I don't think necessary. It seems rather limited.
If it's limited at all, it would only be limited by expense of the materials and regulations that are even stricter than they are for normal chemicals. The chemistry itself, if performed safely, has quite a bit of potential, and is no more limited than non-radioactive chemistry. I think that having the new subforum would be a great idea, and I too am quite eager to see some radiochemistry procedures posted.

careysub - 21-8-2014 at 15:53

Quote: Originally posted by The Volatile Chemist  
Sometimes (According to Wikipedia's element classifications page) Heavy metal refers to poisonous metals/metal ions.


Often it is used that way true, but would that then include the extremely light beryllium as a "heavy metal"?
Quote:
Anyways, is David Hahn's 'work' documented is his book mostly correct?


Not sure if you asking whether Hahn's understandings of science and his procedures were mostly correct, or whether the book is mostly correct.

I'd have to say both are shaky.

He was stunningly ill-informed, and his efforts terribly misguided (leaving aside the stealing and lying).

If I use myself at his age as a benchmark, I would say he failed to grasp many rudimentary principles at 17, that a smart science-oriented kid could have mastered at 12 or 13 (because at that age I could have set him straight).

He seemed to have no real grasp of the physics - he was practicing more like a form of sympathetic magic, attempting to copy procedures without understanding whether they made sense or not. It was "cargo cult" science.

Ken Silverstein is journalist and does not understand any of this stuff either and regularly gives Hahn way too much credit. There is also an odd dynamic going on in which he interviews adults connected with the case, and elicits words of admiration about Hahn's activities, but what they are responding to is what Silverstein is telling them, not from their own personal knowledge.

Albert Ghiorso reviewed the book and was extremely kind is his review, as befits a giant of radiochemistry reviewing the work of a chemical "script kiddie".

Extracting Uranium Ore

careysub - 21-8-2014 at 16:29

Since several time people have requested some actual chemistry here, I will start with some comments about a project I am working on to develop a process diagram for extracting interesting nuclides from uranium ore.

I am still in the research phase - remembering that old adage "A year in the laboratory can save you a day in the library".

Uranium ore is more interesting to extract than thorium ore since it has two ancient nuclides (U-238 and U-235), not just one (Th-232), and both are higher up the periodic table so that there are more radionuclides they can decay into before becoming stable.

From the point of view of the element collector I count five elements of interest to extract from uranium ore:
natural uranium itself (lifetime billions to hundreds of thousands of years)
Ra-226 (1602 year half life)
Pb-210 (20.4 year half life)
Pa-231 (327,600 year half-life)
Ac-227 (21.77 year half life)

Of course, you can just display the original ore chunk and declare all the nuclides known to be therein. But it is more interesting to separate them to the extent possible.

Pb-210 is of interest because it is the parent nuclide of Po-210 (138 day half-life). You can extract Po-210 as part of the process, but in a year or two it will be effectively gone. If you instead extract Pb-210 then you have a quasi-permanent source of Po-210.

The Ra-226 and Ac-227 are both "two for one" wins for the element collector: Ra-226 always producing Rn-222, and Ac-227 decays into Fr-223 (half life 22 minutes).

In researching this subject I found that except for the original work by Mme. Curie the literature on extraction is only interested in one particular product (e.g uranium, or radium, or protactinium) and aren't interested in a flow that will isolate multiple species, so Curie's original work remains very informative.

I don't like the United Nuclear procedure for ore extraction, using the carbonate for the following reasons - it is applicable only to very alkaline ores, which are in a minority; it is less efficient than acidic extraction; most work done on nuclide extraction uses an acidic process flow; and in particular it is not well suited for the tributyl phosphate extraction procedure it promises to later use.

You are better off starting off with an extraction using sulfuric acid. If you do have an alkaline ore then I suggest neutralizing it first with inexpensive HCl and evaporating before commencing with the sulfuric extraction.

neptunium - 21-8-2014 at 18:01

i had a book long ago where the work of Marie Curie was detailled and the procedure had all the element extraction...for the life of me i cannot find it ! :mad:
note that M Curie started with one metric ton of high quality ore and obtain 1 gram of radium giving its standart activity of 1 curie!
1000kg of pitchblend would today cost a small fortune and is way out of reach for any home radiochemist!
not mentionning the fact that your house would pop up on a radiological radar like lighthouse at night.
in my thread on radioisotope identification http://www.sciencemadness.org/talk/viewthread.php?tid=27963
i have just identifyed a few element in the gamma spectrum of a sample of euxenite.
for the element collector its proof that the element is present and that is probably enough for me ! so far...

careysub - 21-8-2014 at 20:18

Quote: Originally posted by neptunium  
i had a book long ago where the work of Marie Curie was detailled and the procedure had all the element extraction...for the life of me i cannot find it !


The work you are referring to is either Marie Curie's thesis "Radioactive Substances" or her later book "The Discovery of Radium", both can be downloaded from Archive.org.

Another level of interest in carrying out an ore separation process, modeled on Marie Curie's work is the essential importance of coprecipitation. It was the isolation and purification of radium where the laws of coprecipitation were discovered and clarified. All of the people whose names are attached to these laws (Fajans–Paneth–Hahn; Doerner-Hoskins) were radiochemists who worked with radium.

[Edited on 22-8-2014 by careysub]

neptunium - 22-8-2014 at 07:55

i let sulfuric acid digest 70.3 g of monazite in order to start with the sulfuric liquor of thorium it is brownish yellow and is still disolving at the moment...some chumks refuse to disolve though .
when finished (maybe another 24hours or so) i will filter it and run a spectrum on both filtra and solution...
should be interesting.

neptunium - 22-8-2014 at 14:53

the filtra is pale yellow (the picture exagerate the color)

filtra.JPG - 208kB
i believe most of the uranium and thorium should be in that solution.
could be wrong though but i pick up a lot more radiations from the precipitate than the solution.... a spectro gamma will surely clear that!

[Edited on 22-8-2014 by neptunium]

neptunium - 22-8-2014 at 16:49

this is the spectrum of the precipitate . wich seems to contain most of the activity... the sulfuric liquor may contain the Thorium and uranium salt...

compare.bmp - 4.8MB
it isnt very suprising since lead radium etc sulfate will precipitate and stay in the filter..
i am going to disolve the rest in HCl and see what happens...what do you guys think?

[Edited on 23-8-2014 by neptunium]

neptunium - 23-8-2014 at 08:20

here is the precipitate from ammonia action on the filtra of the sulfuric liquor...


compare Ac228.bmp - 3.6MB

notice how Actinium stayed in solution but Th and lead at least are still there and even in higher amount the Thorium peak is off the chart and the Pb hasnt changed very much...

let me remind you that this is 70.3 gram of ore to begin with and this precipitate is less than 3gram

careysub - 23-8-2014 at 09:43

Quote: Originally posted by neptunium  
the filtra is pale yellow (the picture exagerate the color)


i believe most of the uranium and thorium should be in that solution.
could be wrong though but i pick up a lot more radiations from the precipitate than the solution.... a spectro gamma will surely clear that!

[Edited on 22-8-2014 by neptunium]


At last we have an actual ore extraction process post! Good show!

Where did you get the monazite?

neptunium - 23-8-2014 at 09:46

i have a few rocks sample from ebay....where else! lol

careysub - 23-8-2014 at 10:08

Quote: Originally posted by neptunium  
i had a book long ago where the work of Marie Curie was detailled and the procedure had all the element extraction...for the life of me i cannot find it ! :mad:
note that M Curie started with one metric ton of high quality ore and obtain 1 gram of radium giving its standart activity of 1 curie! ...


Marie Curie was really using uranium mining tails, the waste material after the uranium had been extracted. For her purposes this was better than fresh ore since the mining company had done the first stage of concentration for her. The tails were 4.5 times more active than the ore, and being waste at the time, it was free.

I am having trouble coming up with a specific figure of much tails she processed, "several tons" is the usual quoted amount.

There are hundreds of piles of uranium mining tails scattered over the uranium mining regions of the U.S. The NRC is charged with monitoring these, and has a database of them - but I haven't come up a list yet.

On the other hand there is an accessible database of every uranium mine in the U.S. maintianed by the EPA: The Uranium Mine Database http://www.epa.gov/rpdweb00/docs/tenorm/402-r-05-009.pdf

You can download it as a DBF file (my OpenOffice spreadsheet program opens it as a spreadsheet without any problem):
http://www.epa.gov/radiation/docs/tenorm/uld-ii.dbf

The list is apparently very complete, when the Texas mines were compared to the state of Texas' own official list, it had every mine Texas knew about, and some that it didn't. It includes also claims that were never actually mined.

Using Google Maps you can look up the geolocation of each of the mines for a little recon.

Texium - 23-8-2014 at 20:01

So you're thinking of doing a little midnight uranium hunting? Doesn't seem like the best idea, but I hope you succeed!

Edit: Wow, I had no idea that south Texas had so many uranium deposits!

[Edited on 8-24-2014 by zts16]

careysub - 24-8-2014 at 13:14

Quote: Originally posted by zts16  
So you're thinking of doing a little midnight uranium hunting? Doesn't seem like the best idea, but I hope you succeed!

Edit: Wow, I had no idea that south Texas had so many uranium deposits!

[Edited on 8-24-2014 by zts16]


The uranium minerals currently on the market are largely obtained by collectors frequenting old mine sites. People do this openly.

See for example:
http://carlwillis.wordpress.com/2008/02/20/uranium-chemistry...

IrC - 24-8-2014 at 13:35

Out in the wilds zts16 you will likely not be bothered by anyone so long as you stay off of posted property. I have pounds of ore from many sites all over Arizona which were long ago abandoned. Of course my collecting was done decades ago but I imagine abandoned locations abound to this day. Wear a sidearm and watch out for Western Diamondbacks among other critters. IIRC John Wayne once said of the desert "everything wants to stick you stab you or kill you".

Or in other words pay attention when collecting rocks around cracks and crevices where snakes like to hide from the heat. Better yet do most your collecting during the winter months as I used to do. Wear gloves, don't breathe dust from tailing piles, etc., the usual common sense precautions.

careysub - 24-8-2014 at 16:35

Quote: Originally posted by IrC  
Out in the wilds zts16 you will likely not be bothered by anyone so long as you stay off of posted property....


Or more affirmatively - the ticket is to stay on BLM land, unless some special restriction is in place, everyone is has a right to go there.

careysub - 25-8-2014 at 13:01

Quote: Originally posted by careysub  
...
I'm not sure you can find anything but low grades of uranium ore on the surface in the U.S. are any more. Uranium is still heavily mined, and the "low hanging fruit" was dug up long ago. Surface deposits were prospected for very intensely during the 1950s and early 1960s.

If all you can find is 0.1% grade, then even at $10/g your ore would only be worth $10/kg and you have to dig up several hundred kg to finance your prospecting expeditions just to break even..


I see the errors in my thinking now.

To the mining industry only bodies of minerals in quantities large enough to commercially mine are "ore", and must be extractable by (virtually) labor-free mechanized equipment. This means they completely ignore small deposits of uranium, no matter how concentrated they aren't considered "ore". And even after an area is "mined out" there can be a lot of hot rocks lying around.

Unlike a rockhound, miners aren't going to be scouting the ground with detectors.

So while 1% ore is considered "high grade" these days, there can still be much accessible material with content of 10% or even higher for the picking.

Marie Curie's Extraction

careysub - 26-8-2014 at 12:16

I tracked down Marie Curie's account of how much material she processed and how much radium she extracted.

She worked with 7 tonnes of tails, which was 4.5 times as radioactive as the original ore, so it was the equivalent of about 30 tonnes of pitchblende. She isolated 0.2-0.3 g of radium, which is about 250,000 microCuries, and would exist in equilibrium with some 750 kg of natural uranium. This indicates the original ore averaged 2.5% U.

The Volatile Chemist - 3-9-2014 at 12:37

This is some wonderful chemistry! In future years I hope to go back to it, and repeat some of it.
Quote:
a chemical "script kiddie".


Wow. That is SUPER accurate. Being a 'kiddie programmer' at a younger time, that hit home even more than the concept o cookery instead of chemistry, or the kewls. Maybe a Quiche Eater Chemist (If you've read the letter 'Real Programmers Don't Use Pascal').

Regardless, it seems to me this would make a great subforum. Cost IS the major limit, but could be overcome. What would be problematic with larger quantities of ore (for getting reasonable product) is reagents to reduce the ore to compounds workable.

Marvin - 4-9-2014 at 02:42

careysub,

When were you going to tell us what you were proposing wasn't legal under the regulations you were quoting?

careysub - 4-9-2014 at 05:31

Quote: Originally posted by Marvin  
careysub,

When were you going to tell us what you were proposing wasn't legal under the regulations you were quoting?


Come on Marvin, if you want to debate this issue then do it.

State you what's on your mind, don't resort to a fake question.

You are awfully active on the Energetic Materials site, much of which directly violates criminal law, to adopt this faux offended pose.

If you want a debate you will have to uphold your end of the discussion.

Ante up.

[Edited on 4-9-2014 by careysub]

Texium - 12-9-2014 at 21:36

Wow, I just now noticed the new radiochemistry subforum... awesome!

The Volatile Chemist - 13-9-2014 at 13:48

That's great! Congrats guys, making history on SM :)

unbibium-292

quantumcorespacealchemyst - 22-11-2014 at 04:26

have you all heard/read about the possible discovery of a super actinide

Possible natural occurrence

"On April 24, 2008, a group led by Amnon Marinov at the Hebrew University of Jerusalem claimed to have found single atoms of unbibium-292 in naturally occurring thorium deposits at an abundance of between 10−11 and 10−12, relative to thorium.[29] The claim of Marinov et al. was criticized by a part of the scientific community, and Marinov says he has submitted the article to the journals Nature and Nature Physics but both turned it down without sending it for peer review.[30] The unbibium-292 atoms were claimed to be superdeformed or hyperdeformed isomers, with a half-life of at least 100 million years.[27]

A criticism of the technique, previously used in purportedly identifying lighter thorium isotopes by mass spectrometry,[31] was published in Physical Review C in 2008.[32] A rebuttal by the Marinov group was published in Physical Review C after the published comment.[33]

A repeat of the thorium-experiment using the superior method of Accelerator Mass Spectrometry (AMS) failed to confirm the results, despite a 100-fold better sensitivity.[34] This result throws considerable doubt on the results of the Marinov collaboration with regards to their claims of long-lived isotopes of thorium,[31] roentgenium[35] and unbibium.[29] It is still possible that traces of unbibium might only exist in some thorium samples, although this is unlikely.[27]

It was suggested in 1976 that primordial superheavy elements (mainly livermorium, unbiquadium, unbihexium, and unbiseptium) could be a cause of unexplained radiation damage in minerals. This prompted many researchers to search for it in nature from 1976 to 1983. Some claimed that they had detected alpha particles with the right energies to cause the damage observed, supporting the presence of unbihexium, while some claimed that no unbihexium had been detected. However, the possible extent of primordial unbihexium on Earth is uncertain; it might now only exist in traces, or could even have completely decayed by now after having caused the radiation damage long ago.[18]"

from http://en.wikipedia.org/wiki/Extended_periodic_table

it reminds me of the story of the curies. processing tons of ore.

i don't know much about this and am guessing that even though "A repeat of the thorium-experiment using the superior method of Accelerator Mass Spectrometry (AMS) failed to confirm the results, despite a 100-fold better sensitivity".it may be possible that using a different technique to verify or disprove the finding is not entirely scientific. and perhaps using the same teqnique, Replication, has a different outcome. it is not even mentioned if they used the same ore.

[Edited on 22-11-2014 by quantumcorespacealchemyst]

neptunium - 5-12-2014 at 18:40

the island of stability has long been speculated to lye somewhere arround z=126 in the periodic table.
this claim if bold and has little if any proof. this Marinov guy has a lot of balls...
I wonder howany one could explain the formation of deformed nucleus in nature with an atomic number of 122!
supernovae do create element beyond iron but how far beyond the actinides? and how much of it would be left today when the last speculated closest supernovae happened 5 billion years ago ?
even with a half life of 100 million years assuming traces amount at creation (considering how much actinides are left in nature today) thats still 50 times its half life! not much is usually left after 10 periods...
sounds bogus.

[Edited on 6-12-2014 by neptunium]

careysub - 6-12-2014 at 09:16

Quote: Originally posted by neptunium  
...
even with a half life of 100 million years assuming traces amount at creation (considering how much actinides are left in nature today) thats still 50 times its half life! not much is usually left after 10 periods...
sounds bogus.
...


There was a claim in 1971* that Pu-244, with a half-life of 70 million years (making it the longest lived plutonium isotope) had been detected in bastnasite at a very low level, which would have made the shortest half-life nuclide of primordial origin to be detected on Earth. Recent studies using material from the same mine, but using the far more sensitive accelerator mass spectrometry failed to find any at levels much lower than originally reported, thus disproving the original paper.

However, it is really believed highly likely that there is some Pu-244 on Earth, but it may be so little that we will never detect it.

The is one primordial nuclide, Sm-146, with a half-life of 107 million years that has been detected with some confidence. But here we have the advantage of being able to obtain large amounts of pure samarium from nature in which to look.

So *IF* there are super-stable super-heavy nuclides with half-lifes of 100 million years, then some should be here, and there is some possibility that some atoms can be found.

* D. C. Hoffman, F. O. Lawrence, J. L. Mewherter, F. M. Rourke: "Detection of Plutonium-244 in Nature", in: Nature 1971, 234, 132–134

[Edited on 6-12-2014 by careysub]

neptunium - 6-12-2014 at 11:12

some of these element could have been formed by neutron capture from cosmic ray or spontanious fission.
lf a few atoms are distributed here and there the only way to tell if they are primordial or not would be in the evironment in which they are found.

working in the radio chemistry lab of a nuclear plant years ago ,i remember getting flags of Be7 on the spectrometer from time to time (53 days half life) which is a part of a natural cycle . Although different situation,
exotic nucleides are present on earth from natural processes,

careysub - 6-12-2014 at 12:24

Quote: Originally posted by neptunium  
some of these element could have been formed by neutron capture from cosmic ray or spontanious fission.


Not Pu-244, or any superheavy element.

Creating these requires successive neutron captures in a short period of time, since some (or many) of the intermediate nuclides decay quickly, and thus very intense neutron fluxes are required. In nature only supernova nucleosynthesis provides this, where it is called the r-process (for "rapid").

In non-saturation conditions (i.e. everywhere except supernovas or thermonuclear weapons) the production rate decreases exponentially with each successive capture, so it drops to effective zero after a small number. Nature can make Pu-239, Pu-240 no doubt, maybe detectable amounts of 241 or 242 (not sure whether these have been detected) but that's it.

neptunium - 6-12-2014 at 13:52

the natural reactor in Africa is the proof of what nature can do alone.. so if Pu244 cannot be generated, where does that leaves us for Unbibium 292 and Marinov`s claim?
exactly!!

careysub - 6-12-2014 at 14:11

Quote: Originally posted by neptunium  
the natural reactor in Africa is the proof of what nature can do alone.. so if Pu244 cannot be generated, where does that leaves us for Unbibium 292 and Marinov`s claim?
exactly!!


He is looking for primordial super-heavy elements that may have survived from the last supernova explosion in the r-process to enrich the solar system at its birth, not ones made on Earth by natural fission or cosmic ray neutrons. Since Sm-146, with a 108 million year half-life has survived from that event, then other 100 million year half-life nuclides will as well.

But without an inert natural carrier (stable samarium) there is no known way for the them to become concentrated to detectable levels, if they exist.

Think about the samarium situation. Stable isotope ratios vary throughout the solar system at the level of a few percent or less.* So any ancient samarium, however far it has decayed today, will still be present in any modern samarium sample, if there is any at all. This is really helpful in finding it.

When looking for new elements, which may exist on Earth at the same quantity, we do not have this convenient concentration and identification mechanism.


*This variation is due to fractionation processes after the early nebula collapsed (and which is thought to have been thoroughly mixed and quite uniform).

S.C. Wack - 6-12-2014 at 20:15

My Great-Great-Aunt Discovered Francium. And It Killed Her.
By VERONIQUE GREENWOOD DEC. 3, 2014
http://www.nytimes.com/2014/12/07/magazine/my-great-great-au...

Interesting IMHO.

neptunium - 18-10-2015 at 08:41

Quote: Originally posted by careysub  
Quote: Originally posted by neptunium  
the natural reactor in Africa is the proof of what nature can do alone.. so if Pu244 cannot be generated, where does that leaves us for Unbibium 292 and Marinov`s claim?
exactly!!


He is looking for primordial super-heavy elements that may have survived from the last supernova explosion in the r-process to enrich the solar system at its birth, not ones made on Earth by natural fission or cosmic ray neutrons. Since Sm-146, with a 108 million year half-life has survived from that event, then other 100 million year half-life nuclides will as well.

But without an inert natural carrier (stable samarium) there is no known way for the them to become concentrated to detectable levels, if they exist.

Think about the samarium situation. Stable isotope ratios vary throughout the solar system at the level of a few percent or less.* So any ancient samarium, however far it has decayed today, will still be present in any modern samarium sample, if there is any at all. This is really helpful in finding it.

When looking for new elements, which may exist on Earth at the same quantity, we do not have this convenient concentration and identification mechanism.


*This variation is due to fractionation processes after the early nebula collapsed (and which is thought to have been thoroughly mixed and quite uniform).



also the rocky planet concentrated most of the heavier element and the gas giant capture some of the lightest after the sun ignited.
i would not be surprised to find higher concentration of gold or thorium on mercury than on the mars or titan for example. it might be a small difference though.
Most recent space probe carry along mass spectrometers capable of identifying some isotopes (active or not) it would be very interesting to dig in those results and compare them...

The Volatile Chemist - 24-10-2015 at 12:27

Have there been any attempts to produce atoms of 122-126 in colliders?
I'd heard about the natural-122 stuff when I was 13, but back then thought the 'island of stability' was the location at which the isotopes had been found. I note Wikipedia has pages for the theoretical heavy elements, and what methods have been tried to produce them.

doublefocusing - 20-4-2016 at 11:40

Radiochem? Love to see it. Shame the readers weren't around when the nuclear chem courses were dismantled at the small colleges.At some point such facilities were deemed politically inappropriate, the planchettes, minature glassware, source kits and all that wonderful old counting equipment went on the scrap pile.If you worked at one of the U's that had a pile, put your sample in the"rabbit"push the button and off it went, to be retrieved later.Really wasn't much of a problem getting accelerator time either. Even the little schools frequently had a Pu-Be source.
Now? with all the wonderful stuff floating around on the net, low level counting looks pretty accessible.Scintillation counters everywhere and a variety of solid state detectors.A neutron generator straightforward to build. Be prepared to develop a good bit of skill with vacuum line tech. Safety? Mostly overblown,but these are the risks of curiousity,

neptunium - 4-11-2021 at 03:05

Quote: Originally posted by doublefocusing  
Radiochem? Love to see it.

Granted
https://www.youtube.com/watch?v=ulY9QA4729U
Quote: Originally posted by doublefocusing  
with all the wonderful stuff floating around on the net, low level counting looks pretty accessible.Scintillation counters everywhere and a variety of solid state detectors.A neutron generator straightforward to build. Be prepared to develop a good bit of skill with vacuum line tech. Safety? Mostly overblown,but these are the risks of curiousity,


No comments

Random - 22-10-2024 at 03:52

Quote: Originally posted by Brain&Force  
Quote: Originally posted by careysub  
For Am-241 the skin dose is only 1 mRem, and if it were in a test tube the exposure would be zero (gammas are too weak to penetrate).


You need lead sheets to stop gamma rays. Test tubes won't cut it.

I would be interested, but what kind of projects do you have in mind (specifically, with what elements/sources?)


If it is so called Gamma Ray, that is transmutative so Gamma Ray would transmute material of Test Tube unless this type of Radiation can bypass Test Tube material without transmuting the material.