# Where is my gold ?



## Scrap-Algeria (Jul 22, 2017)

Dear friends:
I tried to refine some gold scrap with AR ,everything goes well i end up with brown precipitate, wash it with HCL then with distilled water ,so i put in furnace with borax, finelly i broke the borax and unfortunately nothing is there just black borax.
What am i doing wrong?
Some told me that i must use torch not furnace.............why ?
Thank you guys


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## jimdoc (Jul 22, 2017)

Scrap-Algeria said:


> Dear friends:
> I tried to refine some gold scrap with AR ,everything goes well i end up with brown precipitate, wash it with HCL then with distilled water ,so i put in furnace with borax, finelly i broke the borax and unfortunately nothing is there just black borax.
> What am i doing wrong?
> Some told me that i must use torch not furnace.............why ?
> Thank you guys



How much and what type was this "some gold scrap"?


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## Scrap-Algeria (Jul 22, 2017)

Actually it was 18g of gold jewellery scrap 14 karat and 9 karat.


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## justinhcase (Jul 22, 2017)

Scrap-Algeria said:


> Actually it was 18g of gold jewellery scrap 14 karat and 9 karat.


Did you inquart it and leach base metals?or just go straight to A.R.?
What Precipitant did you use?
Borax douses not go black with moderately clean Au.


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## Scrap-Algeria (Jul 22, 2017)

Thank you guys for your answers, unfortunately i went straight to A.R process and then i'd used SMB to precipitate gold.


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## justinhcase (Jul 22, 2017)

Scrap-Algeria said:


> Thank you guys for your answers, unfortunately, i went straight to A.R process and then I'd used SMB to precipitate gold.


How did you assess the alloys you started with?
I am unfamiliars with French Hallmarks and any one can put a stamp on a bit of metal so they are only ever a guide.But they help a little.A good U.K. Hallmark can normally be trusted.
There are not many low karat alloys that will go straight to A.R.
How did you prepare your A.R. Liquor?did you reduce down or use sulfamic acid?


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## Scrap-Algeria (Jul 22, 2017)

i assessed the alloys with jewellery acid, and i prepare my AR (ration 1 nitric acid with 3 HCL) and i used sulfamic acid than SMB.


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## justinhcase (Jul 22, 2017)

Scrap-Algeria said:


> I assessed the alloys with jewelry acid, and I prepare my AR (ration 1 nitric acid with 3 HCL) and I used sulfamic acid than SMB.


When you say"Jewelry Acid" I take it you mean a scratch test on a stone.
I never like to use Just Sulfamic acid to neutralize the Nitric, I always reduce down as far as possible then use sulfamic instead of a second evaporation.This is quite volatile enough but I do work on larger batches.
It is a good indicator that all the nitric has been taken care of when the reaction stops.
What detritus was left over from your original digestion ?
How much of each karat did you have? so we can work out how much value you are looking for.


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## Scrap-Algeria (Jul 23, 2017)

I had 11.06g 9 karat 6.94g 14 karat.


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## anachronism (Jul 23, 2017)

So you're looking at approx 8.2g of gold (give or take.)

Have you kept your solutions?


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## Scrap-Algeria (Jul 23, 2017)

I precipitate the gold , i guess no solution is kept


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## Scrap-Algeria (Jul 23, 2017)

Could the furnace and crucible be the problem ?


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## g_axelsson (Jul 23, 2017)

How much borax did you use? Any pictures?

As I see it you started with gold alloy and dissolved it directly in aqua regia.

If the gold wasn't dissolved it would end up in the filter when filtering the solution. Do you have the filter and solids left after the aqua regia treatment? Were there any solid bits left?

The dirty liquid was treated and finally you used SMB. This might precipitate the gold depending on how well you got nitric acid out of the solution. Any nitric left might redissolve the gold. It sounds like you got rid of the solution so if there was any gold left then it is lost by now.

The brown precipitation you got was washed in HCl. What was the color of the liquid?

You added borax to the powder, how much? Did you use a clean crucible? Did you pour out the borax while it was fluid?

If the temperature wasn't high enough to melt the gold or the borax not fluid enough then the powder might be mixed in with the borax and impossible to see with the eye.

There are numerous threads on the forum to how to melt gold with a melting dish and a torch, the amount you are talking about is perfect for that method.

So your gold might be in the solids left from dissolving the gold, in the liquid that you discarded or in the borax in the crucible.

Göran


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## justinhcase (Jul 23, 2017)

The thing I like about refining is that it takes Locard's exchange principle to extremes.
a perpetrator of a crime will bring something into the crime scene and leave with something from it,"Every contact leaves a trace".
What refiners have learned to do over the centuries is to limit that cross contamination.
Study the fundamentals and the rest falls into place.


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## Scrap-Algeria (Jul 23, 2017)

Dear friends thanks for the help...*g_axelsson* you ask an interesting question which made me rethink.....
1- I think i used too much borax ( see the pic bellow)
2- Do you have the filter and solids left after the aqua regia treatment? no solid just little dirt.
3- Any nitric left might redissolve the gold... i used sulfamic acid (till no fizz) to make sure no excess nitric acid.........
4- The brown precipitation you got was washed in HCl. What was the color of the liquid? the color was lightly yellow.......
5-You added borax to the powder, how much? Did you use a clean crucible? Did you pour out the borax while it was fluid? Actually it was new crucible , and i mix the brown precipitate with borax in crucuble then put it in furnace...about 30 minute.

If the gold was left in the borax in the crucible what should i do?


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## anachronism (Jul 23, 2017)

I can see your gold in that.


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## Topher_osAUrus (Jul 23, 2017)

Scrap-Algeria said:


> 2- Do you have the filter and solids left after the aqua regia treatment? no solid just little dirt..



Coincidentally, a lot of finely divided precious metals look like different kinds of dirt..

First time I showed my father in law precipitated gold, he didn't believe me until I melted it..

We cannot judge by aesthetics alone, testing is necessary for qualitative answers


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## Scrap-Algeria (Jul 23, 2017)

*anachronism* where you can see it ? i just saw a yellow glass.......


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## anachronism (Jul 23, 2017)

Well unless my eyes are playing tricks on me which they could be, youve got what look like tiny bubbles and nodules in there. When I've recovered gold from borax in the past for other people those have contained tiny prills of gold. 

Again it could be my eyes. That given, if you were going to get your proper yield from the materials as mentioned above I would have expected a good lump of gold in one piece.


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## Scrap-Algeria (Jul 23, 2017)

thanks for sharing guys................


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## anachronism (Jul 23, 2017)

You used WAY too much borax for this melt. Boil your borax in water and it will dissolve. A bit of sulphuric (not too much) wouldn't hurt and if there is gold there it will be left in the bottom. You can pour off the water and replace if it doesn't seem to be dissolving any more.

Oh and prior to this crush the borax in a mortal and pestle or something like that to increase the surface area.


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## Scrap-Algeria (Jul 23, 2017)

Thank's *anachronism* i'll give it a shot...........


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## kernels (Jul 24, 2017)

Why is the borax black ? With precipitated gold in a clean crucible surely it should be clear ? 

Do you have any pictures of the precipitated brown gold powder ? Would be good to see if it looks like 8g


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## Scrap-Algeria (Jul 24, 2017)

kernels ,that's what was made me wondering "what the heck"...in picture below you see the precipitated brown gold powder washed with distilled water ........


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## anachronism (Jul 24, 2017)

The borax is black from the impurities. If you didn't wash in HCl and went straight to melt then they will be pulled into your borax.


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## g_axelsson (Jul 24, 2017)

That does not look like gold to me. Coming from Aqua Regia I would expect aluminium or tin to be the problem, most other metals should have dissolved. 

Precipitated gold forms an easily filtered heavy powder. 8 grams of gold is less than a teaspoon of powder, even when wet, and that looks like a lot more.

I like Anacronism's suggestion. Grind and dissolve the borax, if there is any gold it shouldn't dissolve and it will stay on the bottom. Then when you have some concentrated material a few drops of HCl and a drop of nitric acid should dissolve enough gold to give a solution you could test with stannous chloride.

Read up on testing and stannous.
http://goldrefiningwiki.com/mediawiki/index.php/Stannous_chloride

Göran


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## justinhcase (Jul 24, 2017)

I would like to go back to the very beginning.
I occasionally have eighteen karat alloy from tourist destinations that will go straight into solution.But they are only about 5%. of what I find.
Most are alloyed with silver which retards such direct digestion.
Just to double check you started with a good alloy it would help to run through how you tested with "Jewelers Acid" and check your field assessment was accurate.
Thick rolled gold or bonded can give quite a nice scratch test if you are not aggressive enough.


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## Topher_osAUrus (Jul 24, 2017)

justinhcase said:


> Thick rolled gold or bonded can give quite a nice scratch test if you are not aggressive enough.



Agreed, and some substrates can be very deceptive


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## Shark (Jul 24, 2017)

A few years ago I did a test using a necklace marked 18K, made in Italy. The necklace was a fake. Stannous test was negative. No gold what so ever. While cleaning up my mess, the filter looked a lot like the one posted by the OP. Thanks to the forum, I now test smaller portions.

On a side note, I still have a similar necklace with identical markings, it is a fake also.


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## anachronism (Jul 24, 2017)

I really would prefer to take the approach that the material is "as described" and help the guy recover his gold rather than take the view that he has been conned. That's a cop out. When all other avenues have been exhausted THEN look at those options but until then, and given the OPs experience the first approach should be the one adopted.


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## Topher_osAUrus (Jul 24, 2017)

So what is it then? Too much smb and he reduced TONS of base metal out, then didn't wash it properly?

I dont really see any gold prills in the slag, although in tbe first picture it does look like it has a couple golden hued spots, probably from the lighting.


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## anachronism (Jul 24, 2017)

I believe the process that's been followed has been wrong, and that's what we should help him rectify Chris mate. It's a classic case of removing all the variables and then and only then thinking that he's been conned.

What you you think?

Jon


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## Shark (Jul 24, 2017)

I much prefer to think he has not been conned. But his picture of the filter brought back an experience I had almost forgotten. While I wasn't conned on the material, it was an interesting experience that I did learn quite a bit from.



anachronism said:


> I believe the process that's been followed has been wrong, and that's what we should help him rectify Chris mate. It's a classic case of removing all the variables and then and only then thinking that he's been conned.
> 
> What you you think?
> 
> Jon



And this is how I think also, his methods have left him in a bind, and I am curious also to see how it turns out.


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## justinhcase (Jul 24, 2017)

the simplest hypothesis proposed as an explanation of phenomena is more likely to be the true one than is any other available hypothesis,
You can just about prove it by testing all the possible places your value could have turned up.
If you find nothing you have much less than you thought.


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## anachronism (Jul 24, 2017)

justinhcase said:


> the simplest hypothesis proposed as an explanation of phenomena is more likely to be the true one than is any other available hypothesis,
> You can just about prove it by testing all the possible places your value could have turned up.
> If you find nothing you have much less than you thought.



In your view Justin what is the simplest hypothesis?


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## justinhcase (Jul 24, 2017)

anachronism said:


> justinhcase said:
> 
> 
> > the simplest hypothesis proposed as an explanation of phenomena is more likely to be the true one than is any other available hypothesis,
> ...


No that would be William of Ockham (c. 1287–1347),
It was his logical hypothesis that underlies most logical thought and most fundamental sciences.
If you can not find it it was not there.


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## anachronism (Jul 24, 2017)

No, what's your view in this particular case?


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## justinhcase (Jul 24, 2017)

If you can not find it it was not there to start with.
I have seen nothing to indicate that the original alloy was as stated.


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## anachronism (Jul 24, 2017)

justinhcase said:


> If you can not find it it was not there to start with.
> I have seen nothing to indicate that the original alloy was as stated.



What about the facts of the case. The OP isn't experienced. He's made mistakes all the way along the process. Wouldn't you need to discount those before taking the easy option of "the gold wasn't there in the first place?"


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## justinhcase (Jul 24, 2017)

anachronism said:


> justinhcase said:
> 
> 
> > If you can not find it it was not there to start with.
> ...


Logical there are a limited number of possibilities.
It is easy enough to test for the presence of Au, Test each and every possibility.
eliminate each in turn.
The chap assures us that he got a complete digestion, then De-NOXed and precipitated with the correct reagent.
If it quacks like a duck and waders it may well be a duck
Speculation is futile.
Just hope he kept every thing.
But my money is on rolled or plated goods.
It looks like just trace to me.may be looking for micrograms not grams.
When you use more precipitant than is required to drop all your value you just start to drop base metals instead.


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## Topher_osAUrus (Jul 24, 2017)

Its truly hard to say for sure, since the solutions are gone.
Without knowing what the solutions looked like, seeing the sediment remaining after the dissolve, or seeing a stannous test or 3. We are poking around in the dark. The blind leading the blind, sort of deal.

But, we CAN, however, still work with what we still have.
That being, the borax. 
OP needs to follow your advice Jon, break up the borax. Dissolve as much as he can in hot water(weak sulfuric is better). And go from there.
If lucky, we will see some prills on the bottom of the beaker.

If we are unlucky, then maybe it is time to talk further about misstamped articles of jewelry. :evil:


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## g_axelsson (Jul 24, 2017)

Too much SMB shouldn't reduce other base metals. SMB can reduce Copper(II) chloride into coppe(I) chloride and precipitate white crystals, but those easily dissolve in HCl so that would not carry on to the melting.

What do we have left to investigate?
- Solids left over from aqua regia digestion? Probably not but we don't know that yet.
- Liquids? No, it's been discarded already so we can't investigate that.
- Powder after precipitating with SMB? Only a picture of the original powder in a wet filter.
- Melted product? Yes, it's all embedded or dissolved in borax. We have already suggested how to test it for any gold.

Sure, we will help this guy out as good as we can, but there are a couple of things to consider and with that sludge in the filter I don't know what else to suggest than the alloys wasn't what it claimed to be from markings.

If the gold has been discarded then there isn't a lot we can do.

So... 
- Either there were almost no gold in the beginning but then there should have been at least some gold in the mud.
- Or an error along the way put the gold in the filter or in the liquid.

If there is a small amounts of gold in the borax then it is highly probable that there is all there was and the goods were plated or filled (rolled for you Brits).
If there are no gold in the borax then it was probably discarded by an error in the process.

Göran


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## anachronism (Jul 24, 2017)

g_axelsson said:


> If there are no gold in the borax then it was probably discarded by an error in the process.
> 
> Göran



And THAT my friend is the approach I am advocating. To view this as a con job before removing the likely factors is merely the easy option. Let's be analytical about it before pointing fingers.


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## Topher_osAUrus (Jul 24, 2017)

g_axelsson said:


> Too much SMB shouldn't reduce other base metals. SMB can reduce Copper(II) chloride into coppe(I) chloride and precipitate white crystals, but those easily dissolve in HCl so that would not carry on to the melting.
> ....
> Göran



If the strong aqua regia was not diluted before precipitation, the smb can create silver-sulfur complex (I cannot recall if its sulfide, sulfite, or sulfate  -my books are at my new house, I am at my old one)

Edit to add

If that was the case, the slag could become pretty black from that


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## anachronism (Jul 24, 2017)

Topher_osAUrus said:


> g_axelsson said:
> 
> 
> > Too much SMB shouldn't reduce other base metals. SMB can reduce Copper(II) chloride into coppe(I) chloride and precipitate white crystals, but those easily dissolve in HCl so that would not carry on to the melting.
> ...



No that's not gonna be the case Topher. It's way over complicating it. Ive dropping more solutions than I can count without diluting, and never once come across that. Admittedly it might be because I'm good at cleaning but hey.


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## Topher_osAUrus (Jul 24, 2017)

anachronism said:


> Admittedly it might be because I'm good at cleaning but hey.



That is the key point I was trying to get across.
Without washing the precipitate properly, all that junk in the mix with the gold powder is going to do nothing but cause more problems.

He said there was a little "dirt" on the bottom after dissolve, so we could probably assume that is a little bit of the silver chloride. But, his strongly mixed AR most certainly held some in solution.
And. He didnt mention if he added the sulfamic and smb in crystal form or aqueous. If the sulfamic was dissolved in water, that would have helped eliminate the silver chloride in solution.


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## anachronism (Jul 24, 2017)

The Silver Chloride really isn't the issue. Actually I mentioned the cleaning way back in the thread though as a reason for the colour of the Borax. I can't see how these things would affect the result in terms of gold unless the gold hasn't been dissolved and precipitated in the first place.


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## Topher_osAUrus (Jul 24, 2017)

anachronism said:


> The Silver Chloride really isn't the issue. Actually I mentioned the cleaning way back in the thread though as a reason for the colour of the Borax. I can't see how these things would affect the result in terms of gold unless the gold hasn't been dissolved and precipitated in the first place.



Looks like we are about out of variables then.

So, unless he finds some prills in the borax, its nothing but bad news all around Im afraid.


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## Lino1406 (Jul 24, 2017)

Look at the positive side: after all it is not so much for learning fee (I paid more, much more)


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