Swiss Dental alloy

[Swissgoldrefiner]

So, few days ago i bought this different stuff of dental alloy.
1. Contain 538/1000 of Pd and 380/1000 of Ag.
2. Contain 512/1000 of Au and 386/1000 of Pd.
The probleme is with number 3 which is melted. I dont know what was inside, but i suppose it should be PM.
So i add Nitric and try to dissolve it. But (first mess), i didnt use distilled water, so the solution started to be cloudy (because of AgCl).
I saw as well some small indissolved compound, so i decided to use HCl to precipitate the Ag and to dissolve the undissolved compound.
It works and all Ag precipitate (when i add more HCl, no more precipitation). The solution have green yellow color as you can see in my picture, bottom is AgCl precipitate.
So i tryed to do a stanous test. Very strange thing happen: When i add the stanous, the solution or the paper go cloudy.
Like i have more Ag in my solution. How i can have Ag in my solution? Worse, then i add small amount of the solution and add stanous, it first turn white cloudy, but then it change color to gray...like AgCl do when you let it on light.
Anyone get same thing with stanous test?

 

[Swissgoldrefiner]

I think i got my own answer...It seems that it's because of HgCl2...
Now the question is how to remove the mercury...lol

 

[AMS-Pro]

A mercury retort, or, if you feel like building a bigger inexpensive setup, a mercury capture system. The EPA website has a manual you can download to build a MCS with a 55 gallon drum. You would go to the EPA official website, and type in "Manual for the construction of a Mercury Capture System for use in gold processing shops.".

Edit* I needed to add this for peace of mind.
- Please be careful when working with mercury. Just like everything else on here, mercury is very dangerous, with affects on the body that are irreversible. Mercury is extremely dangerous in any form and should be avoided if possible, especially in vapor form. If you do have to work with it, make sure you have the proper equipment to do so. Please be safe.

 

[orvi]

I think i got my own answer...It seems that it's because of HgCl2...
Now the question is how to remove the mercury...lol

Mercury is many times present in dental alloys - mostly the most abundand dental "fillers".

Be careful with HgCl2, it is quite lipophillic - it absorbs through skin easily. Also some basic gloves do not very well protect from it in a long run.

I will test if the solution contain any other values such as gold or PGMs, but judging from the colour of it... not very much. But I may be wrong.

Personally, if you don´t have some trusted retort system already built, I will go with wet process (if you intend to refine it despite mercury). Soluble mercury compounds are very toxic - but you can contain them easily in your beaker with catching pan under it. And from the solution, mercury is easily precipitated with copper plate/wire. It forms and drip to the bottom of the beaker. Any other noble metal will also precipitate together with it, so you should strip the solution from them before you proceed to treat the waste solution with copper.
Bear in mind that mercury will stick to the copper surface and also contamine it. Best is to catch all of the mercury, transfer it to some bottle suitable for storing such hazardous substance and also throw in the used copper. Cover everything with water to minimize unwanted evaporation of mercury.

Material with mercury is pain to process, because mercury start to pile up in your waste, and mercury in any form is regarded as hazardous waste - so it is quite difficult to get rid of it properly. More hassle on your side, and on the other side somebody feeling lucky about getting rid of hazardous waste and getting some buck out of it simultaneously.

 

[Swissgoldrefiner]

Thank you guy to prevent me from dangerous chimical. However, i worked often with HgCl2 in organic chemistry. I wound work with dimethyl mercury, but HgCl2 is not that big problem.
To back to my reacction, as some well known member will say: If doubt, cement out. So i cement out it on Copper.
The PM will do an amalgam with mercury. Next step is to make evaporate the merury. I know they doing it for Gold and to prevent dangerous vapor, i may need to do it in distillation aparatous.
However, i am going try to find a way to avoid distilation mercury...