Sciencemadness Discussion Board - Should 99.99% mercury contain slag? [Update from seller]

Should 99.99% mercury contain slag? [Update from seller]

Rutherford - 18-10-2019 at 13:42

I recently purchased mercury for demonstration purposes. The mercury was purchased from Onyxmet and it states it is 99.99% pure. What would be this slag floating around? Is this normal?

I'm just wondering if I should contact them... because it certainly isn't as clean as I thought it would be.

My first theory was that it would be iron oxide, considering the mercury probably came from an iron flask but it isn't magnetic.

[Edited on 19-10-2019 by Rutherford]

Ubya - 18-10-2019 at 13:48

If I remember correctly not all iron oxides are magnetic, so probably it is just rust

Rutherford - 18-10-2019 at 13:54

Do you think this would merit a chat with the vendor?

morganbw - 18-10-2019 at 15:12

I think a chat would be in order.

DavidJR - 18-10-2019 at 16:18

If it's just that small amount of insoluble crud then that could quite easily still meet the 99.99% spec considering how dense mercury is... Of course, there could be dissolved metals too, but i'm not sure i'd worry about that just because of some insoluble crap floating on top.

Boffis - 19-10-2019 at 01:16

Even the purest mercury oxidizes slowly and more importantly absorbs sulphur from the atmosphere. Sulphur generally cretes a black scum the browner colours are generally the oxide. Traditionally mercury has to be cleaned periodically by dripping into dilute 10% nitric acid. The aqueosu phase is easily separated from the clean mercury which is then washed with water remove the remaining nitric acid. Don't through the washings down the drain! Kept them for next time.

This procedure should give you nice shiny mercury.

Rutherford - 19-10-2019 at 03:36

Quote: Originally posted by Boffis

Even the purest mercury oxidizes slowly and more importantly absorbs sulphur from the atmosphere. Sulphur generally cretes a black scum the browner colours are generally the oxide. Traditionally mercury has to be cleaned periodically by dripping into dilute 10% nitric acid. The aqueosu phase is easily separated from the clean mercury which is then washed with water remove the remaining nitric acid. Don't through the washings down the drain! Kept them for next time.

This procedure should give you nice shiny mercury.

I think I will try that, would you recommend I first past it through a plunger? Or will the nitric acid take care of this brown oxide?

G-Coupled - 19-10-2019 at 03:54

If you feel brave, and wish to try distilling your Mercury to purify it, both NileRed and Cody's Lab have pretty good videos on YouTube on how they did it.

NileRed

Cody's Lab

[Edited on 19-10-2019 by G-Coupled]

Rutherford - 19-10-2019 at 04:37

Quote: Originally posted by G-Coupled

If you feel brave, and wish to try distilling your Mercury to purify it, both NileRed and Cody's Lab have pretty good videos on YouTube on how they did it.

NileRed

Cody's Lab

[Edited on 19-10-2019 by G-Coupled]

I don't have the necessary safety equipment to perform a mercury distillation. Awesome videos though, I love both of those channels.

draculic acid69 - 19-10-2019 at 05:01

Looks more like copper than rust.

UC235 - 19-10-2019 at 06:29

You can just let it drip through a pinhole in a folded filter paper. The oxides stick to the paper and the mercury comes out shiny. I have some mercury and it has all eventually gotten cruddy looking despite good storage.

Ubya - 19-10-2019 at 06:57

Quote: Originally posted by draculic acid69

Looks more like copper than rust.

copper forms an amalgam with mercury, so i doubt that it would flow on it and do nothing

fusso - 19-10-2019 at 07:06

Those red stuff looks like rust more than Cu or HgO to me.

Rutherford - 19-10-2019 at 09:59

He sent me this. On the one hand I feel bad for him, but then again it costed like 150€. What do you guys think would be a fair amount? Or just clean it with a syringe and move on?

[Edited on 19-10-2019 by Rutherford]

Ubya - 19-10-2019 at 10:28

if it is just that stuff on the surface you can filter it through a syringe with a cotton plug at the bottom, you won't loose much Hg

fusso - 19-10-2019 at 11:08

Quote: Originally posted by Boffis

Traditionally mercury has to be cleaned periodically by dripping into dilute 10% nitric acid.

HNO3 will also dissolve Hg. Why isn't HCl better?

[Edited on 191019 by fusso]

S.C. Wack - 19-10-2019 at 11:51

Because HCl isn't an oxidizer or a better solvent. In the sphygmomanometer thread I gave a method that works well. Shake violently for 2 min. w/ conc. KMnO4, wash, shake again for 2 min. w/ cold dil. HNO3, wash, dry w/ something lint-free. No mercury is dissolved even though it's in a very finely divided state.

G-Coupled - 19-10-2019 at 12:36

Quote: Originally posted by Rutherford

He sent me this. On the one hand I feel bad for him, but then again it costed like 150€. What do you guys think would be a fair amount? Or just clean it with a syringe and move on?

Ehh, if it's a really small percentage of the total amount you were sold, and you think you might be dealing with them in the future, it might be best to just let him know and to eat the (hopefully small) cost. Might buy some goodwill for the future, maybe?

karlos³ - 19-10-2019 at 13:23

Try to clean it up first, a small amount of course, and only then complain.
Tom is a very good guy and most helpful, he will surely replace it if your cleanup fails.

draculic acid69 - 19-10-2019 at 15:19

Quote: Originally posted by Ubya

if it is just that stuff on the surface you can filter it through a syringe with a cotton plug at the bottom, you won't loose much Hg

Sounds like the best thing to do.then try the paper with a pinhole method.if that doesn't work I'd be asking for a replacement.

Rutherford - 19-10-2019 at 15:41

Quote: Originally posted by karlos³

Try to clean it up first, a small amount of course, and only then complain.
Tom is a very good guy and most helpful, he will surely replace it if your cleanup fails.

Yeah he is great. He ended up offering me some more mercury at a reduced rate, which I think I'm going to take.

j_sum1 - 19-10-2019 at 17:07

Sounds like a good option all round.
You get experience with handling and cleaning Hg, which is a good thing.
You get a reasonable quantity of Hg at a good price.
Tom gets an additional sale and a happy customer.

Boffis - 21-10-2019 at 09:26

10% nitric acid attacks mercury rather slowly, the oxide dissolves almost instantly. By the time the mercury drops have coalesced its time to pour off the acid and wash with a small amount of water several times. I collect the water washings separately let them evaporate down to a small volume spontaneously and then store them until I have enough to be worth reprocessing.

diddi - 21-10-2019 at 13:12

all my purchases from tom have been good. just saying.
Hg is easy to clean. i shake in HCl, then KMnO4, then water rinse and a dilute HNO3. then us a sep funnel to run it off. HCl is good for removing stuff like Zn that can be amalgamated.
sometimes I receive old portions of Hg from people so anything is possible in terms of contaminants. if i get any from possible Au prospectors i have to distill, but i usually do a batch rather than messing around setting up for small amounts.

Bezaleel - 22-10-2019 at 06:11

Quote: Originally posted by Boffis

(...)
I collect the water washings separately let them evaporate down to a small volume spontaneously and then store them until I have enough to be worth reprocessing.

So the mercury stays in solution? Or does it just evaporate slower?