Mercury? Lead sulphate?

[autumnwillow]

I'm not sure what it is, but could anybody tell me? I'm just curious as it is a bit unusual.
How do you guys detect if mercury is present?

 

[g_axelsson]

Dual layers like that with a gradually changing border could be from different densities because of different salt concentrations. Sometimes you can see a similar phenomenon in copper chloride when you have CuCl₂ at the top and CuCl at the bottom, in that case the border only shows how far oxygen have diffused down to oxidize the copper.
In both cases the border disappears if you stir the solution. If it reappear and moves slowly downwards over time then it's probably caused by oxygen.

Mercury chloride isn't soluble in water, it will follow silver chloride. But if you inquart the gold first I would suspect that you already boiled off any mercury when melting gold and silver.

Lead sulfate would only be present if you have added any sulfuric acid. Did you do it?
Anyhow, you should filter off the white precipitate as it clearly isn't gold.

Göran

 

[Topher_osAUrus]

I honestly haven't the slightest clue just from the pictures, but, -while the pictures help, a little background on what you have processed to get there also helps.

If you had lead in your process, it wouldnt be lead sulphate unless you added sulfuric to ppt it out of solution. Or if you added sulfamic to denoxx your ar solution which in turn creates sulfuric acid and makes the lead chloride turn to lead sulphate.

What makes you question mercury? Dental scrap? Old electronic scrap?

 

[autumnwillow]

Lead sulfate would only be present if you have added any sulfuric acid. Did you do it?

The white precipitate came out after dilution, I filtered the solution to remove the white precipitates then I added sulfamic acid(aqeuos).
Yes I'm a bit wrong here, I should have added sulfamic acid before dilution.

What makes you question mercury? Dental scrap? Old electronic scrap?

Because I am afraid of mercury, we have melted a very small amount of mercury containing gold dust before and I could feel its toxicity 5 meters away from the melting dish (itchiness on my skin). But thanks to Goran for reminding me that the boiling point of mercury is very low, so I am now sure that the gold button(mined from cyanide process I believe) that I processed did not contain any mercury.

 

[nickvc]

If you suspect Mercury my advice stay well away from it, it is a cumulative poison that stays in your body.
I'm not too sure but if Mercury has been used in the area the gold came from it can I believe form even more toxic chemicals once mixed with cyanide, perhaps one of our chemists can clarify that point so anyone reading this thread is fully aware of any risks.

 

[Topher_osAUrus]

Lead sulfate would only be present if you have added any sulfuric acid. Did you do it?

The white precipitate came out after dilution, I filtered the solution to remove the white precipitates then I added sulfamic acid(aqeuos).
Yes I'm a bit wrong here, I should have added sulfamic acid before dilution.

What makes you question mercury? Dental scrap? Old electronic scrap?

Because I am afraid of mercury, we have melted a very small amount of mercury containing gold dust before and I could feel its toxicity 5 meters away from the melting dish (itchiness on my skin). But thanks to Goran for reminding me that the boiling point of mercury is very low, so I am now sure that the gold button(mined from cyanide process I believe) that I processed did not contain any mercury.

Sorry, i have yet to have my coffee so i may jumble my thoughts. But, the white ppt coming after dilution tells me its silver chloride, which is only in solution in very strong acids.
You didnt necessarily do it wrong(sulfamic addition timing)...you could have done it before hand, and it would have dropped the silver chloride, and lead as lead sulphate. Which could be separated later...kind of a pain(not really, just takes up time from other processes)...

The way you did it seems fine. Filter again after sulfamic addition. Then you should have your lead gone, assuming there was enough nitric to neutralise by the sulfamic (since that is what makes the sulfamic into sulfuric which makes the lead sulfate) to ppt out all lead that may have been there.

So what caused your itch?!?....inquiring minds MUST know...kidding.
I know what that itch is... Its gold fever induced dermatitis... I have it all day everyday... It makes me lose sleep!