Nitric nightmare - gold filled, help please

[ImTechMan]

Mistakes were made. :roll:

Bought a 1.4 kilo lot of "tested" gold filled more as an experiment than an attempt to make money, luckily. As it's looking like that is how it's going to go.
:|
Short version, I didn't retest. There were magnetics, after the nitric had issues digesting I filtered the solution and pulled out a ton (red Solo cup) of iron and steel, and the gold didn't "flake off" like I have read it has from a few other people in the forum.

What I am left with is pictured below, green fluid I am assuming is nitric with copper/iron etc. In solution that I syphoned from the top and the other container is a brownish fluid with foam on top, it no longer reacts to more nitric and there is no "mud" at the bottom, it also hasn't had time to settle but still, I do see some gold specs floating around but am unsure how to proceed any recommendations would be very welcome. Also, more as a side question... What is the foam? (I'm assuming it's waste that caught bubbles from the fumes from the nitric, but there may be gold flakes?) And should I attempt to process it? If so, what is the best way?

 

[Topher_osAUrus]

No big deal.
It can be saved, assuming it IS goldfilled stuff you have and not just plated crap.

Couple questions first.
1.) What is the brown solution?
--am I understanding this correctly? -You decanted the green solution, removed all the iron stuff, then added more nitric? Is the bubbly brown stuff a wash you did, or is it fresh nitric? Is that where the rest of the material is still? Was the nitric added to the nonmagnetic stuff (and produced no reaction?)

2.) How much nitric have you used so far?
--It will take a lot of it to dissolve all the base metal from 1400g of goldfilled. Sometimes, if magnetic stuff slips through, the red/brown iron salt ends up going into solution on its own after subsequent nitric additions. 2nd, 3rd, 4th sometimes (really, that is dependent upon the concentration)

**If it were me, I would add about 50mL of 5-10% H2SO4. It will readily dissolve that rusty brown stuff that the nitric created from the ferrous articles. Add it slowly, even though it is diluted, it can cause a vigorous reaction.

3.) Is there any markings on the iron stuff that you can see? Is it indeed goldfill?
--If yes to 3, then you might as well add it back in. It is going to need processed sometime anyways, might as well finish your trial by fire like a champion.


--There is really NO foils that are floating? not even any little baby specs of gold?

Your green Solution. Let it settle overnight, slowly decant the clear top portion, filter off any sediment/particulates and add them back to the rest of the stuff. Add a piece of copper to the green solution to see if any silver cements to it (doubtful, but do it just in case)

All is not lost, you can do it!

 

[g_axelsson]

Foam is often easily knocked down by using a spray bottle with plain water.

Göran

 

[Palladium]

Yep ! Iron.

Get a 5 gallon stainless cook pot to run it in. I hope you didn't put 1.4 kg in that small vessel.

 

[ImTechMan]

No big deal.
It can be saved, assuming it IS goldfilled stuff you have and not just plated crap.

I did test that much at least, I clipped a few pieces in half, pulled some of the gold off ran through nitric, melted and tested with acid, I only did that with a few of the larger pieces though.

Couple questions first.
1.) What is the brown solution?
--am I understanding this correctly? -You decanted the green solution, removed all the iron stuff, then added more nitric? Is the bubbly brown stuff a wash you did, or is it fresh nitric? Is that where the rest of the material is still? Was the nitric added to the nonmagnetic stuff (and produced no reaction?)

I did decant the green solution and filtered the brown mud like substance, and got a lot of undigested iron/steel filtered out and removed. After that I added fresh non-dilute nitric (70% pure, no distilled water added as I read in this forum that diluting nitric makes iron fall out of solution) the bubbly brown stuff happened before I filtered and added 50/50 Nitric/distilled and after I removed what was left of the magnetics and added 70% pure nitric. And it just looked like no reaction, if I watch closely the whiteish foam at the bottom shoots streaks into the green from time to time, and it has been on a hot plate just under boiling for 2 days now.

2.) How much nitric have you used so far?
--It will take a lot of it to dissolve all the base metal from 1400g of goldfilled. Sometimes, if magnetic stuff slips through, the red/brown iron salt ends up going into solution on its own after subsequent nitric additions. 2nd, 3rd, 4th sometimes (really, that is dependent upon the concentration)

I have used almost 1.5 liters of nitric. I have siphoned and added fresh nitric 3 times now. (After the first time, again I read in this forum that adding distilled water to dilute the nitric causes the iron to drop, so I have only added non-dilute nitric.)

**If it were me, I would add about 50mL of 5-10% H2SO4. It will readily dissolve that rusty brown stuff that the nitric created from the ferrous articles. Add it slowly, even though it is diluted, it can cause a vigorous reaction.

I have some sulfuric for my cell, I don't know the purity though as it's from a battery acid refill kit, I'll do some research and try to make an educated guess as to the concentration and the dilution.

3.) Is there any markings on the iron stuff that you can see? Is it indeed goldfill?
--If yes to 3, then you might as well add it back in. It is going to need processed sometime anyways, might as well finish your trial by fire like a champion.

There were markings some was 1/10 10k and some was 1/20 14k, however all of the gold is off of the iron pieces, everything I pulled out has no gold remaining.

--There is really NO foils that are floating? not even any little baby specs of gold?

I have seen little gold specs through the whole process untill now, I have what looks like a fine white powder a few inches tall, if I stick a Pyrex glass stirrer in, the white "area" doesn't seem to have any density, but about a half an inch from the bottom it feels like I am shoving the stick through mud if that makes sense.

Your green Solution. Let it settle overnight, slowly decant the clear top portion, filter off any sediment/particulates and add them back to the rest of the stuff. Add a piece of copper to the green solution to see if any silver cements to it (doubtful, but do it just in case)

About a half an inch of orange/brown sediment formed at the bottom of the green solution over night. And the green turned from a bright green to an almost black dark emerald green, not sure what that means, but I'll siphon and cement as you recommended, thank you!

Also as pictured overnight the brown liquid (after adding around 500ml of nitric) separated into dark green and white powdery green, I am assuming the nitric is "full" and can't pull any more base metals into solution and it needs to be siphoned and have more nitric added, please let me know if I am right on this.

Also, I am assuming a lot more base metals would go into solution with dilute nitric (70% nitric and distilled water 50/50) but I don't want to risk dropping the iron, if I add the sulfuric (diluted to 5-10% as you had mentioned) will that either, cause iron to drop or drop then digest back into solution? If it digests, could I add the dilute sulphuric, wait for the iron to digest then dilute the solution with distilled water to get more base metals into solution?

And thank you, thank you, thank you for your previous reply! And for just being all around awesome enough to answer my newbie questions!

All is not lost, you can do it!

 

[ImTechMan]

Foam is often easily knocked down by using a spray bottle with plain water.

Göran

I was afraid to dilute and drop the iron out of solution, but that certainly would have been easier then stirring the foam back in with a glass rod, took forever and some of it still ended up drying on the side of the Pyrex pitcher.

Thank you for the knowledge! And the reply!

 

[ImTechMan]

Yep ! Iron.

Get a 5 gallon stainless cook pot to run it in. I hope you didn't put 1.4 kg in that small vessel.

Doh, as feared, as mentioned above I will give the 50ml 5-10% dilute sulphuric a try, still can't help but wondering if after the sulphuric does it's thing if I can add distilled water to solution to pull more base metals into solution. (Without dropping the iron of course)

And regrettably, not this vessel but a 1 gallon vessel very much like it, I was assuming (I know, made and ass out of me) I was just going to add, siphon, add etc. then orange... bubbles, foam etc. Won't make that mistake again!

 

[Topher_osAUrus]

Yep ! Iron.

Get a 5 gallon stainless cook pot to run it in. I hope you didn't put 1.4 kg in that small vessel.

Doh, as feared, as mentioned above I will give the 50ml 5-10% dilute sulphuric a try, still can't help but wondering if after the sulphuric does it's thing if I can add distilled water to solution to pull more base metals into solution. (Without dropping the iron of course)

And regrettably, not this vessel but a 1 gallon vessel very much like it, I was assuming (I know, made and ass out of me) I was just going to add, siphon, add etc. then orange... bubbles, foam etc. Won't make that mistake again!

The sulfuric will solubilize the iron, therefore getting it into solution.
The white stuff you mention could be metastannic sludge, maybe some silver chloride (if you used tap water initially)

I dont use concentrated nitric, at all really. Even if I have iron crap in the mix. I know it will dissolve eventually upon further nitric additions, or if it doesnt, then by adding a very small amount of sulfuric.

Side note - dont use dilute sulfuric for your cell, concentrated only. Else you will have further troubles with that as well.

 

[ImTechMan]

The sulfuric will solubilize the iron, therefore getting it into solution.
The white stuff you mention could be metastannic sludge, maybe some silver chloride (if you used tap water initially)

I dont use concentrated nitric, at all really. Even if I have iron crap in the mix. I know it will dissolve eventually upon further nitric additions, or if it doesnt, then by adding a very small amount of sulfuric.

Side note - dont use dilute sulfuric for your cell, concentrated only. Else you will have further troubles with that as well.

I have 93% pure sulfuric. so I will put 6ml sulfuric with 44ml distilled water to make the 50ml 10% acid recommended above? And add it to solution verrryyy slowly... (If my math is wrong, or I am not correctly comprehending this, please let me know!)

I only ever use distilled water with recovery, not to say there couldn't (definitely we're) have been contaminates in the gold filled.

And thank you for the info! Is 93% sulfuric adequate for my cell?

Also I left the solution heated over night and much more of it turned green overnight!... Although all I see is white powder aside I'm still not seeing gold or brown mud at the bottom =\

 

[ImTechMan]

And now that I take a picture of the top, I see my gold... A fine glitter suspended in the solution... What is the best way to deal with this? Siphon into a filter? I would just add glycerin or dish soap but the gold isn't floating on the solution, but in it, just suspended so it's not a surface tension issue.

 

[Topher_osAUrus]

I have 93% pure sulfuric. so I will put 6ml sulfuric with 44ml distilled water to make the 50ml 10% acid recommended above? And add it to solution verrryyy slowly... (If my math is wrong, or I am not correctly comprehending this, please let me know!)
The math isnt super critical. ...im not much of a stoichiometric refiner, more of a " add it, and react it" guy. That being said. Dilute sulfuric between 5 and 25% should be fine. If there is still some rust after 30 to 60 min, make another small addition of dilute acid. Once it is clear, and if there are no brown fumes (acid is done reacting), let any solids settle, decant, add more nitric and let it work all it will. If this addition of nitric gives you more red rust, do the sulfuric addition again. Iron is a pain, amongst other base metals (they all suck), but it is one that can easily be taken care of (chemically)
I only ever use distilled water with recovery, not to say there couldn't (definitely we're) have been contaminates in the gold filled.
There undoubtedly was contaminants in the g.f.,
solder is annoying, and could be the culprit. Ive also had some enamel (or somethin er other) cause a lot of issues too.
And thank you for the info! Is 93% sulfuric adequate for my cell?
Yep, some of those drain cleaners have inhibitors in them though which can be annoying. It seemed my gold powder wouldnt settle out of the pink kind. After I diluted it a little, it settled out fine. Keep it above 85% though, at least. One book I have says 60%, I think the old patent of western electric said 65% or maybe a little more, but having it that dilute will add base metals to your gold mud.
Also I left the solution heated over night and much more of it turned green overnight!... Although all I see is white powder aside I'm still not seeing gold or brown mud at the bottom =\

Pictures of this white powder on the bottom would be excellent!
It will help narrow it down some

 

[goldsilverpro]

I don't think I would use a stainless container if I were adding sulfuric to the solution. It might be OK but I wouldn't take a chance.

Also, if you do add some of that strong sulfuric, make sure its not added to a hot solution. It could blow back in your face. Make sure the solution has cooled off before you add it.

 

[Palladium]

If it were me, I would combine all contents of everything into a stainless vessel. No sulfuric!
Wash all the residues and everything into it. Their will be a lot of solution.
Put it on heat and evaporate it until you start to see crystals form to get rid of the excess water. Then add enough water to make the crystals go into solution. From there start adding nitric. The iron will go back into solution and you can pick up where you left off. Buy the way if those flakes are like glitter you didn't have gold filled, it's gold plating. What kind of filter will you be using for this? You can easily run a kilo in a 20 quart ( 5 gallon ) stainless pot.

 

[ImTechMan]

Pictures of this white powder on the bottom would be excellent!
It will help narrow it down some

Think you for asking, below I have a close up of the side, the bottom and what the white powder "mud" looks like when I scrape some up from the bottom:

If it were me, I would combine all contents of everything into a stainless vessel. No sulfuric!
Wash all the residues and everything into it. Their will be a lot of solution.
Put it on heat and evaporate it until you start to see crystals form to get rid of the excess water. Then add enough water to make the crystals go into solution. From there start adding nitric. The iron will go back into solution and you can pick up where you left off. Buy the way if those flakes are like glitter you didn't have gold filled, it's gold plating. What kind of filter will you be using for this? You can easily run a kilo in a 20 quart ( 5 gallon ) stainless pot.

doh, already added the Sulfuric, I will try it that way next time (of course depending on the outcome here =P) and I am not doubting there was gold plated probably mixed in, I clipped some of the larger pieces in half so on top of being marked I was also able to verify they were gold filled (some filled with lead or a plasticine/ceramic looking material) and I was going to go with my normal method of a coffee filter with a glass funnel, will the gold particulates be to small? what would you recommend? I tried to get a better close up of the gold specs below if that helps:



Thank you all!

 

[Topher_osAUrus]

Oh, come on ralph. Why you got to hate on sulfuric so much.
Its a lovely, and very useful acid!

 

[Palladium]

And that white tin you keep asking about makes a good stannous chloride under the right conditions ! :lol: :lol: :lol:

 

[Topher_osAUrus]

I don't think I would use a stainless container if I were adding sulfuric to the solution. It might be OK but I wouldn't take a chance.

Yes, definitely dont use stainless with nitric/sulfuric. It can and will eat some types up.
I wouldnt take that chance at all.


OP-
You should have at least a few free floating foils in there if it was goldfilled. The picture of the white paste, and tiny little specs...makes me think that it was a bunch of costume stuff.
They make that out of any and every cheap metal mix you can think of.

Honestly though, I cant say for sure what the white paste is (hopefully someone can)..
It kind of reminds me of tin sludge... But theres just so muchof it

 

[Palladium]

Honestly though, I cant say for sure what the white paste is (hopefully someone can)..
It kind of reminds me of tin sludge... But theres just so muchof it

:arrow: :arrow: :arrow:

And that white tin you keep asking about makes a good stannous chloride under the right conditions ! :lol: :lol: :lol:

:mrgreen: :mrgreen: :mrgreen:

 

[Topher_osAUrus]

:lol:

Hah, well. I hope for our new friends sake, all the tin crap is gone. And it was all preferentially dissolved before the good goldfilled stuff. That way, in the end, he can have some reward for all of his efforts.

But, should it all be plated, if he has a gram in the end, I'll be shocked.
Lets not be negative nancy's though, and try and stay optimistic.

Thats a lot of tin sludge.
Mrs Hoke says sulfuric will dissolve it, but, this is one area that she was just a wee bit off on. It really doesnt help that much in cases like this.

It will be best, I believe (there may be better methods to this, if so hopefully someone speaks up).
Finish dissolving the scrap.
Filter off all solids, including the sludge.
Rinse them well with water.
Slowly dry them, once the water is gone, turn up the heat and then bring to redness (you will need a torch to oxidize the tin sludge)

After the solids have been incinerated well, do an HCl leach to remove the tin. It may take a couple leaches (proper incineration is important, if you didnt expell all the nitric, some gold will dissolve)

After leaching the tin with HCl, you can dissolve the gold foils with your preferred method of aurum oxidation.

 

[ImTechMan]

And that white tin you keep asking about makes a good stannous chloride under the right conditions ! :lol: :lol: :lol:

Sweet! lol, well at least I have all the tin I could ever need =P the tin must be what looked like lead to me when I clipped the jewelry open? was a metalic grey color easy to cut through after the outer shell. The gold metal on the outside flaked off the outside pretty easy as well after I clipped it.

:lol:

Hah, well. I hope for our new friends sake, all the tin crap is gone. And it was all preferentially dissolved before the good goldfilled stuff. That way, in the end, he can have some reward for all of his efforts.

But, should it all be plated, if he has a gram in the end, I'll be shocked.
Lets not be negative nancy's though, and try and stay optimistic.

Thats a lot of tin sludge.
Mrs Hoke says sulfuric will dissolve it, but, this is one area that she was just a wee bit off on. It really doesnt help that much in cases like this.

It will be best, I believe (there may be better methods to this, if so hopefully someone speaks up).
Finish dissolving the scrap.
Filter off all solids, including the sludge.
Rinse them well with water.
Slowly dry them, once the water is gone, turn up the heat and then bring to redness (you will need a torch to oxidize the tin sludge)

After the solids have been incinerated well, do an HCl leach to remove the tin. It may take a couple leaches (proper incineration is important, if you didnt expell all the nitric, some gold will dissolve)

After leaching the tin with HCl, you can dissolve the gold foils with your preferred method of aurum oxidation.

Thank you for being so awesome Topher!
Alright, when I get home I'll filter (im thinking I'll syphon and filter all of the emerald solution off of the top to get mostly "tin free" solution and also all of the floating at least gold colored metal out before filtering the tin sludge, grab the low hanging fruit so to speak.)

Then after filtering, rinse the solids with distilled water, and let dry. Would drying them in the coffee filters in a large bowl crucible in a kiln be advisable to speed up the process? maybe 200F? or just dry them in a pyrex dish on a hot plate? (I have sand in the hot plate to disperse the heat to avoid cracking, seems to work well even when dry.)

Does the torch matter? I have Oxy & acetylene, oxy & propane, just propane and MAPP torches, not sure how fine the solids will be and if one torch might get too hot and melt instead of heat or may blow the solids away (and I have made enough mistakes so I thought I'd ask =P)

And then throw it all into a pyrex container with HCL (should I dilute the HCL with distilled? and if so how diluted? or do I want to avoid water and oxygenating the HCL?)

PS. Topher, I have had many professional lives, Electrical engineer, IT architect, Vet tech, Network engineer and even a mechanic... I can and will learn as quickly as I can, since I have found this forum I have been reading chunks everyday, I hope to become an asset to this forum eventually instead of a burden.

And I sincerely want to thank you for your patience, positive attitude, knowledge and experience! Thank you good sir! If you need any IT, Electrical, Mechanical or Animal advice =P let me know!