Sciencemadness Discussion Board

Uranium ore tests

Jackson - 13-12-2018 at 09:11

Hi, i have a sample of what I belive to be carnotite that i have partially desolved in nitric acid (~20-30%) it is not completely desolved because I didn’t make enough acid (i was using a small ammount of leftover acid from a cellulose nitration). I know uranyl nitrate glows under blakc light but i am not able to get one for a while. Is there any other ways to determine if there is uranium content in it other than a black light?

Thanks,
Jackson

12thealchemist - 13-12-2018 at 09:16

The old-school analytical tests (now hobby chem) from my analysis table book for uranium are:

Jackson - 13-12-2018 at 09:21

Alright. My plan will be to filter out the solids, then precipitate with a base. The urante should look yellow right? My auestion is, will the vanadates also precipitate? Will they make it harder to determine if uranium is there?

Thanks,
Jackson

12thealchemist - 13-12-2018 at 09:32

Which vanadium species you get is very pH dependent. Vanadates are notorious for forming aggregatory polymeric species. Pourbaix diagrams can be helpful here. It appears from the diagram below that at high pH, the vanadates should stay in solution.

vanadium pourbaix diagram.png - 52kB
Diagram from Wikipedia

[Edited on 13-12-2018 by 12thealchemist]

Jackson - 13-12-2018 at 12:01

I have another problem. I no longer belive it is a carnotite ore but rather a zippeite ore.
It matches much better than carnotite. I will upload photos when I get home. It encrusts on the rock rather than being in the rock. There is also a deposit of zippeite near where i found the ore (Mindat link of the deposit near the location: https://www.mindat.org/loc-210847.html). My question is, in some publications, it says it is often found in association with uranopilite, which is water soluble. I can not find anything that says it itself is water soluble but I belive it to be so. It says it forms efflorescent encrustations which are encrustations of water soluble salts but i cannot find anything on its solublilty. Does anyone know what zippeite’s solubility is? Is the precipitation of uranyl compounds by a hydroxide still viable with it?

Thanks,
Jackson

(Edited for spelling)


[Edited on 12/13/2018 by Jackson]

Jackson - 13-12-2018 at 14:08

I have found that at room tempature (25 C) zippeite has a solubility of 0.486295315308 grams per liter. It looks like it would be better to dissolve in acid than water.

DoctorOfPhilosophy - 13-12-2018 at 14:13

Holy cow that's a lot of significant digits.... They are all significant right?

On the topic of significant digits: "According to Jörg Arndt and Christoph Haenel, thirty-nine digits are sufficient to perform most cosmological calculations, because that is the accuracy necessary to calculate the circumference of the observable universe with a precision of one atom."

[Edited on 13-12-2018 by DoctorOfPhilosophy]

Jackson - 13-12-2018 at 16:31

Here’s the picture of the ore sample

ED1501E9-E613-4695-93D1-2A69CA31C64A.jpeg - 186kB

CharlieA - 13-12-2018 at 17:36

Quote: Originally posted by DoctorOfPhilosophy  
Holy cow that's a lot of significant digits.... They are all significant right?

On the topic of significant digits: "According to Jörg Arndt and Christoph Haenel, thirty-nine digits are sufficient to perform most cosmological calculations, because that is the accuracy necessary to calculate the circumference of the observable universe with a precision of one atom."

[Edited on 13-12-2018 by DoctorOfPhilosophy]



My thoughts exactly about significant figures! When I was in college, I can't recall if I ever dealt with more than 4 SF's in lab (classwork is different). And now I try my best to get 3 and am ecstatic to get 4!:)

Jackson - 13-12-2018 at 22:13

After some testing, I think it is a zippeite species of ore. How could I go about extracting this into a soluble compound. I don’t currently have access to HCl because it is out of stock near me but could I use a mixture of sodium bisulfate and table salt to generate it and dissolve the ore with that?

fusso - 14-12-2018 at 04:40

Why is U associated with V in ores/minerals? What relationship do they have?

12thealchemist - 14-12-2018 at 05:45

Uranates and vanadates both have the capability of forming complex anionic structures; the main group equivalent are the aluminosilicates. Uranium was once grouped with chromium, molybdenum, and tungsten prior to the invention(!) of the actinide series. I don't know if vanadium and chromium associate in minerals, however.