Sciencemadness Discussion Board

Cinnabar reduction to mercury (cold)

Alquimia - 5-5-2017 at 07:35

I am searching some reduction process for obtain liquid mercury (an cold reduction process, that doesn't implies the cooling of gaseous mercury).

Classical reduction of mercury sulfide (by cooking) generates big quantities of mercury vapours and gas, and implies the cooling and condensation of these.
I don't have the adequate machinery for this process and want to obtain mercury with safety, without generate big amounts of vapours.

MrHomeScientist - 5-5-2017 at 07:45

I had an idea for this that I never got around to trying: dissolve the cinnabar in acid then "cement" the Hg on a piece of iron flat bar stock. The Hg should bead up and roll off the bar to collect at the bottom of the beaker. Iron is used because Hg does not amalgamate with it. The downsides here are (1) the H<sub>2</sub>S gas produced, and (2) it may not work at all since I've done no research into its viability.

It should be noted that any "cold" reduction is likely to involve solutions of soluble mercury salts, which will be highly dangerous to your health.

[Edited on 5-5-2017 by MrHomeScientist]

Boffis - 5-5-2017 at 13:35

This topic has already been discussed on SM and several perfectly servicable methods are described so UTFSE.

Assured Fish - 5-5-2017 at 19:27

Agreed this already has a thread and a wet method was found, I suggest reading the entire thread and watching this video but if you do plan on doing it just be wary of hydrogen sulfide.

https://www.youtube.com/watch?v=_WYU4MW0WNo

http://www.sciencemadness.org/talk/viewthread.php?tid=18162&...

Derek McOlund - 6-5-2017 at 03:45

Isn't it possible to react HgS with hot sulfuric acid to form H2S and HgSO4? And then you could separate the mercury from sulfate ions through electrolysis. That would have the added advantage that the mercury formed wouldn't have any contamination of zink or aluminium that you'd have from other "cold" reductions.

Booze - 6-5-2017 at 10:15

You don't have some metal piping and a torch? Because I have used that to distill crushed cinnabar and zinc powder.

Also, my pipe distilly thing I made looks like a big U, with the mixture on one end and I blowtorched that for a few minutes.

Booze - 6-5-2017 at 10:16

Quote: Originally posted by Boffis  
This topic has already been discussed on SM and several perfectly servicable methods are described so UTFSE.


For OP's benefit, the search engine on this website is garbage.

[Edited on 6-5-2017 by Booze]

MrHomeScientist - 8-5-2017 at 04:43

Cody's Lab just posted a video on recovering Hg waste that explains why my idea above won't work very well - https://www.youtube.com/watch?v=AzNnQ4O8BTY

At about 4:40 he shows that cementing out with iron results in "flowered mercury" (basically powdered Hg) rather than the liquid blobs I expected. Glad I didn't try it!