HgCl2 mercury cloride from Hgs or vermillion (OTC mercury)

[TotalSynthesis]

I got asked about that topic, so here we go:

Vermillion is a mineral of red/orange color. In it's powdered form it also finds some use as paint. Chemically it is mercuric sulfide, which almost cant be absorbed by the body and therefor it is not considered to be very toxic. It is also known as Cinnabar.

The good thing is, it can be bought OTC on ebay or at art stores. Working with it is also easier compared to elemental mercury, which will spill into thousands of small bubbles if it falls on the floor while breaking thermometers etc.

Vermilion can be bought as powder or as stones, powder ofcourse is better for us, if we get it as stones, we need to crush them with a hammer because the smaller it is the easier it will dissolve and convert into HgCl2.

picture is showing it as stones as well as in it's powdered form:

What we need to do:
Mix hcl and nitric acid in a 3:1 ratio (aqua regia) and then dissolve your powder in it to convert HgS to HgCl2.
It produces nasty fumes, very toxic, so better do that outside. Depending on temperature it will take a bit to completely dissolve and make all the red dust swimming on the surface disappear.

When finished, you will end up with a deep yellow solution containing your HgCl2. If you evaporate it to dryness you will receive your salt. or simply use as it is..

 

[G.Patton]

Do you mean evaporate aqua regia? Isn't it easier to just filter HgCl2?

 

[TotalSynthesis]

well, most of it will be dissolved in the acid, especially if you only do small batches there wont be any visible solids.

I usually use the acid solution as it is and just pour it into the reaction vessel.

I calculate the amount i will need for my reduction, then only dissolve that quantity in aqua regia and use it without evaporation

 

[G.Patton]

Have you obtained HgCl2 as powder from this solution?

 

[TotalSynthesis]

yes sure, depending on the quantity of HgS you add to your aqua regia, you will also see HgCl2 swimming around in the solution. But a lot of it is dissolved in the acid and therefor "invisible" but if you evaporate, all the salt will crystallize and fall out.

when boiling it down, do that under a fumehood or outside and do not breathe that shit in