Gammatron - 21-9-2022 at 10:40
I have a bucket with a couple kg of uranium ore that has already been stripped of U, Pa, and whatever else dissolves in H2SO4. The Ra, Po, Pb and Ac
sulfates are insoluble and still remain in the ore sand. Currently the method I have for extracting these is to mix the sand with hot NaOH solution
(saturated?) to convert everything to soluable hydroxides, decant the solution, neutralize with HCl, and then precipitate the decay products with
H2SO4.
Is this the correct way to go about this? I am not looking to isolate any compounds, rather I wish to isolate the radioactivity so contamination of
barium or small quantities of other things are acceptable.
[Edited on 9-21-2022 by Gammatron]
neptunium - 11-4-2023 at 16:10
There is not much to extract from 2 kg of ore my friend. A lot of the hydroxide are insoluble if I recall .. you will certainly be able to detect
them but for larger quantities you want to get tons of good grade ore!
violet sin - 11-4-2023 at 21:48
I'm guessing that you feel it's still spicy enough there has to be a detectable amount after leaching, or you wouldn't be trying. If I remember
correctly, the actual activity of a given ore sample representing the U235 and U238 isn't that large. Let's see how good the
memory is
https://www.wise-uranium.org/rup.html about half way down the page, under the heading :
Uranium Mill Tailings
"Initially, the total activity in the tailings amounts to about 85% of that in the ore. Within a few months, the isotopes of Th-234 and Pa-234m decay
to the value given by the residual activity of the U-238. The total activity in the tailings then remains constant for more than 10,000 years at about
75% of that in the ore."
" Compared to uranium ore, the alpha radiation of uranium mill tailings and thus the radiation hazard on ingestion or inhalation of tailings (dust) is
approx. 25% lower, while the hazard from radon is unchanged. The external radiation hazard from gamma radiation remains nearly unchanged, while that
from beta radiation is reduced. The chemical toxicity of uranium plays a minor role only in tailings."
Think the graph said it was based on 0.1% U leached to 90% for what it's worth. If it still has 75-80% of it's heat after extraction, I could
understand the temptation, doesn't look like a good idea though. With so little material accounting for such a high reading it could be difficult.
Have you looked into EDTA or something to chelate the metals into sol? I know lead is soluble in sulfamic acid, while not so in sulfuric acid. Get
you some tile haze remover. I found a few titles suggestig EDTA to get some U but they didn't check for daughter compounds. I've seen old papers
talking about sulfamic acid and energy commission investigations but none to share at the moment. I've run out of leisure time perusing the net,
didn't look like a dry well though, some more reading at a later time I guess.
I like reading about this a lot more than the idea processing anything in Kg quantity, lol. Good luck Gamatron
unionised - 12-4-2023 at 04:14
I think treatment with Na2CO3 solution a few times will work better.
Ba(OH)2 is quite soluble, and I guess Ra(OH)2 would be too.
A carbonate leach will remove remaining uranium (and thorium).
Once you have boiled up the leftovers with carbonate and decanted the supernatant a few times you should have lots of stuff as carbonates.
Dissolving that in acetic acid (again, boiling hot a few times) will extract most stuff you might be interested in.
Adding salt will ppt most of the lead as chloride. (That will include radioisotopes of lead)
If memory serves me, adding chromate under weakly acid conditions will ppt Ba (and Ra) but leave Ca and some other metals in solution.
Treatment with dilute H2SO4 will dissolve most metals and convert Ba/ Ra to sulphates.
It's important to remember that none of this affects the total activity, but removing other stuff increases the specific activity (and decreases the
shielding) enormously.
It may also be illegal- check your local laws.