# 2.69 Troy Ounce Fine Gold



## kadriver (Apr 5, 2011)

There is something about the reflection of light on a newly refined bar of gold. 

I just finished this bar. I had a mishap on this one that I will share with the forum, maybe you can learn something from my mistake.

I have been refining small one ounce and below batches of gold.

This batch was larger and it has been quite some time since I did one of this size.

I used a 1000 ml beaker to drop the gold. I remember looking at the 2 liter container and just proceeding with the process (due to my inexperience).

I began adding SMB to drop the gold. I added too much and watched as the solution over flowed the 1000 ml container.

I lost about 2.5 grams all over my work surface.

Another expensive lesson - from now on I WILL use a larger container, and I will place it inside a large clean casserole dish to catch any spillage.

I was very relieved to see that I only lost 2.5 grams - It looked like 10 grams on the table. What a mess.

Thanks for looking - kadriver


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## chefjosh77 (Apr 5, 2011)

Wow, great bar and great pics. A tip of the hat to you sir.


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## stihl88 (Apr 5, 2011)

A very fine bar indeed, well done!


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## joem (Apr 5, 2011)

Your abilties are impressive, congratulations


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## Noxx (Apr 5, 2011)

Very well done, congrats 8)


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## Anonymous (Apr 5, 2011)

Absolutely beautiful gold! I love the texture and the sheen.Very nice quality and purity.


kadriver said:


> I added too much and watched as the solution over flowed the 1000 ml container.
> 
> I lost about 2.5 grams all over my work surface.


If I have to use a smaller beaker,or glassware for some reason,I place it inside of a pyrex baking dish in case it overflows.Then I just pour the solution right back into my container when the exothermic reaction settles.


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## MiltonFu (Apr 5, 2011)

Thats an impressive looking piece of metal. Congrats.


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## glondor (Apr 5, 2011)

Very very nice bar. What was your feedstock?


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## kadriver (Apr 7, 2011)

I used karat scrap.

I inquarted with 925 jewelry then dissolved the silver in 50/50 nitric and recovered the silver.

The resulting gold left over was washed dried and melted into a button.

I did this with about three batches until I had a nice quantity.

I then took all three buttons and inquarted a second time using cemented silver - I used 303 grams of cemented silver to inquart 86.4 grams of nearly pure gold buttons.

I know many here do not agree with a second inquartation - But it sure makes a nice looking bar.

By inquarting twice, I avoid having to dissolve the gold in AR a second time.

I think that the second inquartation produces a more pure gold powder to be dissolved in the AR.

Plus - I have a fear of handling liquid gold (AuCl) in a glass container as the floor in my shop is concrete. 

Thanks for your interest - kadriver


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## HAuCl4 (Apr 10, 2011)

Beautiful bars!. Have you measured the purity?.

Re. The second inquartation. I have managed to produce extremely fine (above 99999, not sure if higher) gold by inquarting fine gold with zinc (in a crucible).

The zinc matrix is more easily removed than a silver matrix contaminant. I know you like to tinker, like me...


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## samuel-a (Apr 10, 2011)

HAuCl4 said:


> Beautiful bars!. Have you measured the purity?.
> 
> Re. The second inquartation. I have managed to produce extremely fine (above 99999, not sure if higher) gold by inquarting fine gold with zinc (in a crucible).
> 
> The zinc matrix is more easily removed than a silver matrix contaminant. I know you like to tinker, like me...



How it was tested?


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## 4metals (Apr 11, 2011)

> The second inquartation. I have managed to produce extremely fine (above 99999, not sure if higher) gold by inquarting fine gold with zinc (in a crucible).



I would think this could make quite a mess. The boiling point of Zinc is almost 300 degrees F below the melting point of gold. That would make for some spitting for sure and evaporation of zinc from the melt. 

Do you have any references concerning the parting of a gold zinc alloy and its efficiency vs a silver inquart? And Sam brings up a good point, How was it tested? There are a lot of nines in your claim!


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## Lou (Apr 11, 2011)

Kadriver,

That's a good looking bar. Very professional. 

@HAuCl4,
I'm with 4metals on this--zinc is very volatile and makes a heck of a mess with it's wispy ZnO. Cadmium also shares this property, and both cob webbs are horrible to get in your lungs and difficult to remove without a very good hood setup.

How did you verify the purity? Past 3N there's really no visual cues and fire assay is lacking, corrected or not.


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## machiavelli976 (Apr 12, 2011)

I like to read some details about inquarting with zinc . 
And about 5 nines assaying too.
Since I'm somehow the black sheep of the forum , I'm happy that '4metals' , 'lou' and 'samuel-a ' have asked about that before me.
Could be a potential dangerous procedure this 'zinc inquartation' ? If it does have any sense , of course.


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## HAuCl4 (Apr 12, 2011)

A student in a university lab did an ICP, by what he said it may be better than 99999.

1-inquart with silver and part with nitric. wash with water.
2-Dry the gold sponge, mix it with 3 times the weight in zinc turnings, add a little charcoal, melt (in a crucible) stir and shot. (the alloy has a much lower melting point than that of gold, and gold dissolves in the zinc)- I read somewhere about zinc dissolving even platinum alloys...that I must try sometime and see to believe.
3-Nitric parting and wash.
4-Dissolve the sponge in HCL+ clorox kitchen grade. Chill and Filter.
5-Drop the gold with boiling ammonium oxalate.
6-Wash with hot HCL, hot water, hot nitric, hot water again, 5-10 minutes each.
7-Melt the gold, and the little zinc matrix left apparently just evaporates.

Takes about 4 hours for a 2 oz piece of 99999+ starting from 18k yellow scrap.

Please report the ultimate fineness here if you try it and run an ICP!

Cheers. 8)


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## 4metals (Apr 12, 2011)

I would speculate, having never tried the zinc portion of this process, that you would have achieved the same measure of success if you just left out the inquart in zinc portion of this process and processes the sponge from the silver inquartation as detailed. 

From my understanding of the original statement the high 9 purity was achieved only from a double inquarting and parting, first in silver and second in zinc. The dissolution and precipitation step in this description adds a level of difficulty which I thought you could avoid from your original statement. 

This process, I agree, will yield a high purity but probably no purer than an inquartation followed by an acid refine with an oxalic drop.


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## goldenchild (Apr 12, 2011)

I just got my readout for a 37.7 gram ingot that I sold. About 14 - 15 grams of the gold in this ingot was processed using zinc for inquartation. It was a mix of 10 and 14k karated scrap. I felt like experimenting. Overall it was a nightmare to inquart with zinc.

Pros:
- Digested super easy in nitric acid(I suppose HCL would have worked very well also)
- easier wash phase after digestion

Cons: 
-as Lou said, lots of smoke and other junk going into the air although I didn’t see webs
-popping: no matter how gradually I heated the metal, after a certain point the alloy would pop(possibly use closed furnace to avoid value loss)
-i mentioned this in another post... if zinc is your primary metal in your alloy it will cement out every other metal in the alloy as you're digesting(you must make sure you do a complete digestion on your scrap).

That being said here is the readout.

View attachment mrj top.pdf


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## Barren Realms 007 (Apr 12, 2011)

Here is a warning for you. Many years ago I welded for a day on some hog crates that were galvenized (zinc coated). During the middle of the night I woke up and was blind, couldn't see a bit. I took a shower and washed my eyes out and ended up with no harm done. So take this warning, be careful when you are working with zinc.


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## machiavelli976 (Apr 13, 2011)

goldenchild said:


> Pros:
> - Digested super easy in nitric acid(I suppose HCL would have worked very well also)



Why should one use HCl to digest inquarted gold ? Cu and Ag from it should still be there. 
Than, another digestion in nitric might dissolve also some gold , if traces of HCl are present.


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## HAuCl4 (Apr 13, 2011)

goldenchild: Apparently you used a torch to melt?. I think sulphuric acid would woork also, but never HCl. The purpose of the zinc inquartation is to wash off silver into the ppm range, BEFORE dissolving the gold as a chloride.

Also I'm not an expert or even competent in ICP, someone else did it, but your ICP analysis report looks very strange to me. :shock:


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## goldenchild (Apr 13, 2011)

machiavelli976 said:


> goldenchild said:
> 
> 
> > Pros:
> ...





HAuCl4 said:


> goldenchild: Apparently you used a torch to melt?. I think sulphuric acid would woork also, but never HCl. The purpose of the zinc inquartation is to wash off silver into the ppm range, BEFORE dissolving the gold as a chloride.
> 
> Also I'm not an expert or even competent in ICP, someone else did it, but your ICP analysis report looks very strange to me. :shock:



This is just a theory. I said I suppose HCL would work. A predominantly zinc alloy, say 80-90% should dissolve easily in HCL. The Cu should dissolve easily and the Ag would obviously be left behind as a chloride. Then after the wash and rinse phase you would have gold sponge and Ag chloride. If traces of HCL were present it would be ok because you would be using AR to separate the Au from the Ag chloride. Also, after dropping the gold, washing and rinsing I would do a second digestion in AR. 

Not an ICP anaylysis. XRF.


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## 4metals (Apr 13, 2011)

Goldenchild,

Do you know what type of XRF they are using? How does this XRF compare to other drops you have done?


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## goldenchild (Apr 13, 2011)

It's not a handheld. Its like the one seen here in the bottom right hand corner. I think it may actually be the same exact one. http://www.spectro.com/pages/e/p010508.htm I have had my gold tested 4 times with this machine and it has been consistent. Each reading has been of higher purity but I attribute that to better practices and techniques on my end. This latest analysis is going on the fridge


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## samuel-a (Apr 13, 2011)

Why strange?

Anyway, expirimenting is always nice. But can't see any reason employing that method when can easily achive same results with duble refining with good AgCl elimination regime and two different precipitants...
spare my mucous tissues from molten zinc effervescence...

btw, did you end up using more or less nitric acid for the zinc parting ?


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## 4metals (Apr 13, 2011)

> spare my mucous tissues from molten zinc effervescence...



now those are words to live by!


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## HAuCl4 (Apr 13, 2011)

samuel-a said:


> Why strange?
> 
> Anyway, expirimenting is always nice. But can't see any reason employing that method when can easily achive same results with duble refining with good AgCl elimination regime and two different precipitants...
> spare my mucous tissues from molten zinc effervescence...
> ...



Would love to read about your AgCl ellimination regime to achieve 99999 (less than 10 ppm silver and other stuff). Parting zinc inquart consumes double nitric than silver, but of course you knew that already.


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## HAuCl4 (Apr 13, 2011)

goldenchild said:


> This is just a theory. I said I suppose HCL would work. A predominantly zinc alloy, say 80-90% should dissolve easily in HCL. The Cu should dissolve easily and the Ag would obviously be left behind as a chloride. Then after the wash and rinse phase you would have gold sponge and Ag chloride. If traces of HCL were present it would be ok because you would be using AR to separate the Au from the Ag chloride. Also, after dropping the gold, washing and rinsing I would do a second digestion in AR.
> 
> Not an ICP anaylysis. XRF.



Not theory. HCl will dissolve zinc, and it is used after smelting with zinc applied to platinum alloys. The powder that is left after HCl treatment is treated with AR easily and quickly. I think it is in Hoke's books somewhere too.


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## goldenchild (Apr 13, 2011)

samuel-a said:


> Why strange?
> 
> Anyway, expirimenting is always nice. But can't see any reason employing that method when can easily achive same results with duble refining with good AgCl elimination regime and two different precipitants...
> spare my mucous tissues from molten zinc effervescence...
> ...



There are a bunch of reasons supporting both sides but I definately would choose silver over zinc for inquarting. And I agree using zinc for this experiment didn't do anything that a double refining couldn't acheive. I can't recall but I think I actually used less nitric inquarting with zinc.



HAuCl4 said:


> Not theory. HCl will dissolve zinc, and it is used after smelting with zinc applied to platinum alloys. The powder that is left after HCl treatment is treated with AR easily and quickly. I think it is in Hoke's books somewhere too.



Yes. I was pretty sure HCL would work on a zinc alloy but I just didn't want to claim something I never tried. I think many would also avoid using HCL because of the Ag chloride but I dont mind dealing with it. Maybe one day I will play with zinc and HCL.


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## Barren Realms 007 (Apr 13, 2011)

I understand your reasons and theory behind using the zinc. My drawback would be if you use the zinc once you dissolve it in the HCL it is lost for good. With silver you are at least able to recover it and reuse it. And as Iron's say every thing but the squeal, and in using the zinc you loose part of the squeal. So why the loose the money?


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## samuel-a (Apr 14, 2011)

HAuCl4 said:


> Would love to read about your AgCl elimination regime to achieve 99999 (less than 10 ppm silver and other stuff).



patience... is a key to that in my opinion.
gold solutions are either diluted (or cooled with ice) and allowed to stand 24 hour or more if time allows.... 
Filtered with slow filter.
Different reducing agents serve to eliminate other metals.
Ammonia washes.
It's easy to forget sometimes (for me at least) that vessels needs to be clean. Using new crucibles or ones that used only for pure gold.

FYI, i have no doubts of your ICP results and its probably possible to do that the way you did, though, cheaper and safer methods may lead to same results.

Cheers, no offense meant.

Sam


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## goldenchild (Apr 14, 2011)

Barren Realms 007 said:


> And as Iron's say every thing but the squeal, and in using the zinc you loose part of the squeal.



Scrapple. Yum.


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## Lou (Apr 14, 2011)

Most of the reason why it works so well is the ammonium oxalate. 

You can reduce gold from DBG with ammonium oxalate and have it assay 5N (check the product literature from Ferro)


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## HAuCl4 (Apr 14, 2011)

Lou: I beg to differ. The DBC/oxalate deal works so well only because silver chloride is not soluble in DBC. Without dealing with silver before the drop it's impossible to get the high purity. Maybe there is a cheap chelating agent for silver chloride to get it out completely of a gold chloride solution.(I think this is what Republic does). I haven't found it yet, when I do I'll post it.

Guys: zinc is less then $3,000 per TON. If you are doing 400 OZ a month, a ton of zinc will last you a year (with 2 zinc inquarts per bar). Unless I had a steady stream of silver to refine at the same time, I'd sell the silver needed for inquarting at the current prices and do it all with zinc. 

You can also recover all of the nitric acid (search for 'Big Johnson' in the forums, a 4metals post). If you can't be bothered, you can use sulphuric acid instead of nitric at substantial savings in a cast iron kettle and after recovering any silver, PGMs and copper via cementation, save the zinc sulphate in a drum. You can recover the zinc with a cheap retort too and some coal once every five years if you feel adventurous...and the sulphuric if you are so inclined to "save".

If you ever try it (the procedure) and run an ICP, please post your results here, and send me a thank you note!. It'll be cheaper than buying standards for the ICPs. If you do the zinc-inquart AFTER a normal SMB refining you'll think your ICP machine is broken!... without the DBC gymnastics. :lol: 

If you don't like the zinc fumes (I didn't see any)...then don't do it!.


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