Question about Green Color Gold Solution and Precipitate

[toddmoore]

I recently tried refining some old jewelry that I had inherited (that was hideous;>)
Although I had approximately 16 grams of both yellow gold and white gold, it so happened that only the white gold jewelry had all the gemstones attached that I was unable to remove manually. So I cut out just those parts and performed the process from the video on diamond removal. Then I washed the diamonds and saved the leftover approx half liter of green colored solution separately.

This is a bit beside the point, but I was also then able to perform the inquartation procedure on the main portion of the gold. In that process I am now at the point where I have a half liter of beautiful clear orange gold acid solution and also a quart of rich clear blue silver nitrate solution. I have these two solutions stored separately from the green diamond removal solution.

I stopped the procedure at that point, because I wondered if/how to deal with the green colored gold solution from the initial diamond removal process. I hoped there would be a way of getting at least the gold from that solution and maybe incorporating that gold solution into main refining process.

I did try to precipitate out any non-gold or silver chloride metals from the green solution by using your ice idea. I actually put the solution into the freezer (not realizing it would actually turn solid ice). So then I let it thaw in my beer fridge over night. The result is that I did get some precipitate. I decanted and filtered to get a nice clear green solution and some gray/brown precipitate in a separate beaker (see attached picture).

From what I described, can you tell me what the green solution is (aside from some gold) and what the off-gray precipitate is?
Can you tell me how to deal with refining these materials?

Thank you for any advice and assistance you may be able to offer.

 

[Geo]

Have you tested the solution with stannous chloride? Is it an AR solution or just a nitric acid leach? It's hard to have gold and silver in the same solution at the same time (excluding cyanide). Give some more details about how you dissolved the metal and any testing that you did.

 

[FrugalRefiner]

This is a bit beside the point, but I was also then able to perform the inquartation procedure on the main portion of the gold. In that process I am now at the point where I have a half liter of beautiful clear orange gold acid solution and also a quart of rich clear blue silver nitrate solution. I have these two solutions stored separately from the green diamond removal solution.

The rich clear blue solution is a combination of silver nitrate (which is colorless), copper nitrate (a rich blue), and probably a few other metals, like zinc, nickel, etc. - whatever was alloyed with the gold that would dissolve in nitric acid.

I stopped the procedure at that point, because I wondered if/how to deal with the green colored gold solution from the initial diamond removal process. I hoped there would be a way of getting at least the gold from that solution and maybe incorporating that gold solution into main refining process.

Nope, it's lost forever now. Sorry, just kidding! I'll answer below.

I did try to precipitate out any non-gold or silver chloride metals from the green solution by using your ice idea. I actually put the solution into the freezer (not realizing it would actually turn solid ice). So then I let it thaw in my beer fridge over night. The result is that I did get some precipitate. I decanted and filtered to get a nice clear green solution and some gray/brown precipitate in a separate beaker (see attached picture).

From what I described, can you tell me what the green solution is (aside from some gold) and what the off-gray precipitate is?
Can you tell me how to deal with refining these materials?

The green solution is a combination of gold and the other metals I mentioned above that may be in your blue solution. If you poured your blue solution into your orange gold solution, you'd create a similar, green solution.

The off-gray precipitate is primarily silver chloride. There could also be some lead chloride, copper chloride, and or mercury chloride if any of those metals were present in the original pieces of jewelry.

You can precipitate the gold from the green solution the same way as your orange gold solution, but the gold will be less pure because it will be precipitated from a much more contaminated solution.

Keep reading and you'll find all the details behind my very brief answers.

Dave

 

[toddmoore]

Thank you Geo and FrugalRefiner.
I used the procedure for removing diamonds so it was an AR solution. I did not test the precipitate yet, but I will try stannous chloride to confirm silver.
Per Sam (who replied to an email), I intend to try using SMB in the green solution to precipitate any gold, wash the gold with HCl, then
water, then dry the powder. I can then enquart or include it along with the main portion of the gold when I repeat the refining process a second time for better purity.
Sound good or have any suggestions? This is my first time so I am all ears. Todd

 

[necromancer]

first time ?

you may want to read http://www.goldrefiningforum.com/phpBB3/viewforum.php?f=39

 

[FrugalRefiner]

Todd,

There are a number of errors:

I used the procedure for removing diamonds so it was an AR solution. I did not test the precipitate yet, but I will try stannous chloride to confirm silver.

Stannous chloride is used to test for the presence of gold, platinum, and palladium in solution. It is not used to test precipitates, and it does not detect silver.

Per Sam (who replied to an email), I intend to try using SMB in the green solution to precipitate any gold, wash the gold with HCl, then
water, then dry the powder. I can then enquart or include it along with the main portion of the gold when I repeat the refining process a second time for better purity.

We inquart gold when it is alloyed with silver in a quantity great enough to cause problems when dissolving it in aqua regia. Once you are dealing with a precipitated powder, you do not need to inquart.

Sound good or have any suggestions? This is my first time so I am all ears. Todd

I hope this doesn't sound harsh, but you aren't ready to be processing yet. My advice would be to stop where you are and spend some more time studying. It takes a lot of time and effort, but if you continue to forge ahead, you may lose some of the gold you're trying to recover and you may hurt yourself or someone else.

If you haven't read it yet, download a copy of Hoke's book from my signature line. It explains both of the errors I've pointed out above.

Best of luck,
Dave

 

[samuel-a]

Todd,

Per Sam (who replied to an email), I intend to try using SMB in the green solution to precipitate any gold, wash the gold with HCl, then
water, then dry the powder. I can then enquart or include it along with the main portion of the gold when I repeat the refining process a second time for better purity.

We inquart gold when it is alloyed with silver in a quantity great enough to cause problems when dissolving it in aqua regia. Once you are dealing with a precipitated powder, you do not need to inquart.

Dear Dave,
Normally, i would agree - no need to inquart a fairly high grade gold powder.
However, since the gold powder is most likely contaminated with Pd (precipitation with SMB)which is very persistent, i have suggested melting and inquarting again. This is a simpler way to clean gold from Pd (and others). The alternative would be to re-dissolve the gold powder and use the Oxalic reduction process.

toddmoore,
I do agree with dave that you should do more reaserch before you proceed. But all in all, it certainly seems that you have done your homework - unlike many others who show up here on the forum (or asking privetly) to be spoon-fed.

Good luck and be safe.

 

[FrugalRefiner]

Dear Dave,
Normally, i would agree - no need to inquart a fairly high grade gold powder.
However, since the gold powder is most likely contaminated with Pd (precipitation with SMB)which is very persistent, i have suggested melting and inquarting again. This is a simpler way to clean gold from Pd (and others). The alternative would be to re-dissolve the gold powder and use the Oxalic reduction process.

Sam,

I guess this is one of those cases where there are many ways to skin the cat (no offense Ralph). I understand your reasoning that the PGMs will follow the silver into a nitric leach after inquarting.

If it were my material, and I suspected PGM contamination, in particular palladium, I would skip the inquartation and simply run a nitric leach on the powder. Any Pd should dissolve in the nitric and can be recovered by cementation. Then I would dissolve the rest in cool aqua regia. The gold will dissolve, but any Pt should remain as a sediment. Finally, I would reduce the gold with copperas, which does not tend to coprecipitate PGMs.

Just another way to skin the cat.

Dave

 

[Harold_V]

If it were my material, and I suspected PGM contamination, in particular palladium, I would skip the inquartation and simply run a nitric leach on the powder.

I agree, although a roast of the gold prior to the nitric wash (to eliminate chlorides) would be desirable.

There's no need to melt when the gold is finely divided. While all of the palladium wouldn't be removed with a nitric wash, the percentage would be appreciably reduced, so a second refining should eliminate it to better than acceptable levels.

Even using SO₂ for precipitation for both of my refinings, palladium was not an issue, in spite of the fact that it was often found in my first refining.

Harold

 

[FrugalRefiner]

If it were my material, and I suspected PGM contamination, in particular palladium, I would skip the inquartation and simply run a nitric leach on the powder.

I agree, although a roast of the gold prior to the nitric wash (to eliminate chlorides) would be desirable.

Yes, definitely. I left out the details like incinerating the powder and full washing protocol of the second refined powder and only mentioned the different approach compared to inquarting.

Dave

 

[Quentin]

I really enjoy reading everyones threads about refining. I haven't completed anything yet, still have to buy all that is needed. I took over a friend of mine that moved and couldn't take the acid and all with. He had thousands of sim cards, ore (complete stones) processors and more all just laying in hydrochloric acid and I think he said 2 bottles of bleach. The buckets had green gold paste on the rims and on the sides, which I believe is gold. I kept it all.

I knew nothing about this when I took over. I think this is going to be my new hobby forever. I can't wait to be able to skin the cat in different ways like you guys do.

Just gotto find some cats now... Kidding... I had a good laugh, when I read frugal say that it's lost forever, then said he was kidding. Even I felt sad for it being lost forever. The kidding part was an awesome delivery. Big ups, hahaha.

 

[Yggdrasil]

Green around the rims is most likely Copper salts, highly unlikely that here are gold there.
Anyway you need some Stannous to test for PMs

 

[user 72646]

The rich clear blue solution is a combination of silver nitrate (which is colorless), copper nitrate (a rich blue), and probably a few other metals, like zinc, nickel, etc. - whatever was alloyed with the gold that would dissolve in nitric acid.

Nope, it's lost forever now. Sorry, just kidding! I'll answer below.

The green solution is a combination of gold and the other metals I mentioned above that may be in your blue solution. If you poured your blue solution into your orange gold solution, you'd create a similar, green solution.

The off-gray precipitate is primarily silver chloride. There could also be some lead chloride, copper chloride, and or mercury chloride if any of those metals were present in the original pieces of jewelry.

You can precipitate the gold from the green solution the same way as your orange gold solution, but the gold will be less pure because it will be precipitated from a much more contaminated solution.

Keep reading and you'll find all the details behind my very brief answers.

Dave

The rich clear blue solution is a combination of silver nitrate (which is colorless), copper nitrate (a rich blue), and probably a few other metals, like zinc, nickel, etc. - whatever was alloyed with the gold that would dissolve in nitric acid.

Nope, it's lost forever now. Sorry, just kidding! I'll answer below.

The green solution is a combination of gold and the other metals I mentioned above that may be in your blue solution. If you poured your blue solution into your orange gold solution, you'd create a similar, green solution.

The off-gray precipitate is primarily silver chloride. There could also be some lead chloride, copper chloride, and or mercury chloride if any of those metals were present in the original pieces of jewelry.

You can precipitate the gold from the green solution the same way as your orange gold solution, but the gold will be less pure because it will be precipitated from a much more contaminated solution.

Keep reading and you'll find all the details behind my very brief answers.

Dave

Hi Dave
Read your reply to this post.
With Silver Nitrate, is it a question of drying and washing the precipitate and then smelt?
This is from left over AP solution, I put some copper and a bit of aluminium inside for a few days.
My other beaker, has lumpy grey-ish solids, slightly lighter in colour.
I see it is best to bubble/stir the cementation process (I am building a bubbling chamber for future instances)
Thanks
MM

 

[Yggdrasil]

Hi Dave
Read your reply to this post.
With Silver Nitrate, is it a question of drying and washing the precipitate and then smelt?
This is from left over AP solution, I put some copper and a bit of aluminium inside for a few days.
My other beaker, has lumpy grey-ish solids, slightly lighter in colour.
I see it is best to bubble/stir the cementation process (I am building a bubbling chamber for future instances)
Thanks
MM

There is no Silver in AP.

 

[user 72646]

Hi,
This is the same solution with the 'silver slick' on surface.. you mentioned in a reply that it protects silver? and that scraping was impractical. I understand AP will not dissolve Ag but may create an Agcl?
it could however be Sn, Pb, Hg, but I have not undertaken the hot water test & (ammonia test) some will not dissolve (Pb) some turn Black (Hg), but i need to re-read... may have that mixed up.
'
Anyway Ag can wait.

What ratio should I dilute gold solution prior to SMB drop?
I have 700ml of solution.
Also the strange incinerated crystals that I posted, dissolved in Hcl and Bleach , given a greenish gold solution the result is pictured.

Peace

MM

 

[Yggdrasil]

Hi,
This is the same solution with the 'silver slick' on surface.. you mentioned in a reply that it protects silver? and that scraping was impractical. I understand AP will not dissolve Ag but may create an Agcl?
it could however be Sn, Pb, Hg, but I have not undertaken the hot water test & (ammonia test) some will not dissolve (Pb) some turn Black (Hg), but i need to re-read... may have that mixed up.
'
Anyway Ag can wait.

What ratio should I dilute gold solution prior to SMB drop?
I have 700ml of solution.
Also the strange incinerated crystals that I posted, dissolved in Hcl and Bleach , given a greenish gold solution the result is pictured.

Peace

MM

What does your stannous test say?

 

[user 72646]

positives Black to grey in variation, I have decanted into 100ml jars and will do 2 separate drops initially with smb, vit c. Then drop the remaining solution with which ever gives the best results smb or vit c?
Will possibly save some to try out the copper powder drop method with stirrer or bubbler and perforated tube.
MM

 

[Yggdrasil]

positives Black to grey in variation, I have decanted into 100ml jars and will do 2 separate drops initially with smb, vit c. Then drop the remaining solution with which ever gives the best results smb or vit c?
Will possibly save some to try out the copper powder drop method with stirrer or bubbler and perforated tube.
MM

We have posted how positive look.
Grey is not in there.
Is this the same material you have worked the whole time?

 

[Martijn]

With Silver Nitrate, is it a question of drying and washing the precipitate and then smelt?

Silver nitrate is quite soluble, you can not dry it and then wash it. It will dissolve.

This is from left over AP solution, I put some copper and a bit of aluminium inside for a few days.

Why Cu and Al?

We have posted how positive look.
Grey is not in there.
Is this the same material you have worked the whole time?

Still using same old spoon?

 

[user 72646]

Hi yes, same material.
there was a few positive readings Vit C dropped a little amount of powder
I've had to recover again with Al.
back to square one.?
Will drop with smb today. powders hcl and bleach and stannous