[douglas450]

My grandfather used to be a jeweler and made some type of clear liquid solution that he would put gold filings/cuttings/pieces etc into and completely dissolve the gold into the clear liquid. My question is, how do I get the gold back out of the clear liquid?

[Arkcon]

If it's a clear liquid, then it is likely a cyanide solution, gold forms a stable complex with cyanides.  First off, you should be very careful with it, hobbyists have been know to die for briefly forgetting the very basic safety precautions cyanide solutions require.  The best plan I can think of is letting it evaporate to dryness in a room no pets and children can enter, then sealing the jar of dry solid and giving it to another gold smith to reclaim.  Many reclamation methods you'd get could release toxic cyanides if you're sloppy about executing them.

[douglas450]

Thanks for the info.  This is helping my father remember more about this now (he has had the solution for about 25 years and as he recalls, there is several ounces of gold in it) and he also recalls that the solution used was called Aqua regia. He thinks that steel wool was dropped into the solution and the gold precipitated out to the bottom of the container.  Any unused steel wool was simply removed and the precipitated gold was heated in a crucible with a little flux to form a solid as opposed to.  Is this logical as compared to the electroplating method?, And how can I determine if the solution is aqua regia?  It is stored in a couple of glass containers.

[agrobert]

Surely you have read this

http://en.wikipedia.org/wiki/Aqua_regia

But it doesn't help you classify whether your solution is a alkaline cyanide solution or if it is truly aqua regia, except that aqua regia should be orange and not colorless.  Heed Arkon's warning.  I wouldn't play around to much if it is a cyanide solution.

[AWK]

Thanks for the info.  This is helping my father remember more about this now (he has had the solution for about 25 years and as he recalls, there is several ounces of gold in it) and he also recalls that the solution used was called Aqua regia. He thinks that steel wool was dropped into the solution and the gold precipitated out to the bottom of the container.  Any unused steel wool was simply removed and the precipitated gold was heated in a crucible with a little flux to form a solid as opposed to.  Is this logical as compared to the electroplating method?, And how can I determine if the solution is aqua regia?  It is stored in a couple of glass containers.

In such a case, metalic Zn is often use

[Arkcon]

Aqua Regia, which I've used, and not just read about, is a mixture of concentrated nitric and concentrated hydrochloric, it is a clear liquid for a few minutes, then turns yellow, then orange and then a bubbling brown, as choking nitrogen dioxide forms and bubbles free, it is in the tube seen next to my right hand (sorry the neoprene gloves make this a bad shot, but you can see it's dark red color.)  Over several days, the acid gasses bubble free, and it stops being aqua regia.  So, I'm pretty confidant, that's not what you have.   

The alkaline cyanide solution, if it encounters any acid, will release hydrogen cyanide gas, if you smell bitter almonds, you might have time to run away and breathe fresh air, and not die.  If you pause at the odor to think about it, you've lost your chance.  I'm not kidding.  Gramps had lots more technical skill, and, I'm sad to say, a little less safety consciousness, than you'll usually find today in industry.

The cyanide solution stays, even if you precip the gold with iron or zinc.  If you rinse, you'll have to do something with the rinse water.  At least bring a goldsmith in on your manipulations.

Heh, anyone get the filename reference?

[douglas450]

I dropped in some pH paper and it turned red. This confirms it's Aqua Regia and not a cyanide solution, correct?

[agrobert]

Hardly.  You've proved an old solution is acidic.  Aqua regia would be colored, as stated previously.  In my opinion you need to have a professional look at your solution.  Better safe than sorry.

[Arkcon]

Acid chloride solutions of gold can be quite stable.  If the pH paper was used properly, it very likely pointed to an accurate pH.  If cyanides have some obscure color reaction with the indicator dye, you're well on your way to making a big mistake.  I'd be happier if a diluted sample was tested with a pH meter, and you got a definitive response, in preference to pH paper.

Gold does funny things to humans.  It's at the same time easy and hard to understand.  People take risks they wouldn't in any other case, and get secretive when the chemical hazards require complete transparency.  Suggestion: Take up your grandfather's craft, and see what you can learn about these techniques.  Or bring in an expert friend of his.  Are the things in your grandfather's work area well labeled, and logged in a notebook or ledger or some sort?  I'm betting not, but it's worth asking you to look more carefully.

[ARGOS++]

Dear Douglas450;

IMHO:   I would use simple “Electrogravimetry” independent what other metal it may contain, resolve all  again in as less as possible, fresh Aqua Regia, bring pH close to 7.0^*), add some potassium cyanide (pH -> ~9 - 11), and start  “Electrogravimetry” again, but this times in selectively manner.
(^*) Maybe you can first destroy the Acid by evaporate it, if heating in a steam hood or outdoors.)

The remaining Cyanide Solution you can at least let get dry on normal air, before . .

This procedure is also possible for quite low concentration, because it is “Analytics”.

Good Luck!
                    ARGOS⁺⁺

[Arkcon]

Like we've said, without a careful labeling or careful notes, you can't be sure each bottle is an aqua regia solution, or a gold chloride solution, or a gold cyanide solution.  And acids and cyanide solutions are dangerously incompatible.  If you're hopelessly obsessed with experimenting (c.f. my comment on gold and the human psyche, above,) I'd hope you'd work with small portions of the solutions, at a time, preferably with excellent ventilation.

[douglas450]

Yeah, I really don't want to mess with it. I'm looking around for someone I can take it to who can tell me what it is and then how I can precipitate the gold out. Not that I want to transport it either.  Thanks for the help.  I'll give you and update when we find out what it is..

P.S. Gramps had NO notes or logs.  These two bottles have been sitting around my dads garage for at least 25 years.

[Borek]

I wonder... adding drop of a silver nitrate solution could clarify situation a little bit.

[Arkcon]

I wonder... adding drop of a silver nitrate solution could clarify situation a little bit.

Well, Douglas, did your grandfather work with silver as well?  Do you have nitric acid, labeled properly, still lying around?  Or a labeled solution of silver nitrate?  Silver is one of the few elements not soluble in a solution of chloride.

[tanuwk]

how to extract gold , so that in solution...
I would  try to extract some gold ore .

best regards
tanu