# my gold turned to chocolate while refining !!!!!



## Oropolis.com.mx (Oct 13, 2011)

Hello everyone, my name is Mario Gonzalez from Puebla, Mexico and i have been refining gold about a year ago, but yesterday i was refining about 300 grams of gold with nitric acid only and suddenly the acid started to turn chocolate color, i asked some colleagues here and they told me that if in this lot was 14k white gold and yes it was white gold in the 300 grams that i refined yesterday, please help me because my gold bar came with less grams that i was supossed.

thank you very much, any help will be appreciatted!,


Mario Gonzalez
Oropolis


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## 4metals (Oct 13, 2011)

Mario,

Welcome to the forum, you posted in a location where you will probably not get a response, this area is for technical problems with the computer and software not with your refining. I moved it to help needed.


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## 4metals (Oct 13, 2011)

Please give us some details about your method, just placing the karat jewelry in nitric acid alone is not refining it completely. Did you inquart the scrap in silver first and then use nitric? 

You will get your best advice when you provide enough details for members to answer you after they know what you are doing.


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## samuel-a (Oct 13, 2011)

Oropolis.com.mx said:


> yes it was white gold in the 300 grams





Oropolis.com.mx said:


> chocolate color



Pd ??

How about testing with SnCl2 or DMG?


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## Oropolis.com.mx (Oct 13, 2011)

Hello my friend, the process that i use to refine is as follows:
300 grams of mixed yellow and white gold.
300 grams of copper 

i melt them together in my furnace and then i start the refining with nitric acid.


thank you very much,

Mario



4metals said:


> Please give us some details about your method, just placing the karat jewelry in nitric acid alone is not refining it completely. Did you inquart the scrap in silver first and then use nitric?
> 
> You will get your best advice when you provide enough details for members to answer you after they know what you are doing.


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## 4metals (Oct 13, 2011)

I do not know how difficult it is to get nitric acid in Mexico but in the US a lot of our members have trouble getting it. For this reason you would be better off using silver to inquart because silver will dissolve in 1/3 the quantity of acid. But in addition, any platinum or palladium in your scrap will be collected with the silver for you to recover. Silver used to inquart and collect by cementation can be used over and over again. If you are processing white gold, there is a chance some palladium is in the alloy. 

You should be able to recover about 22 grams of silver from your spent acid the way you are doing it now so it would only be a matter of time until you collect enough silver to use it instead of copper. 

You are still not fully refining the scrap, you are cleaning it up to about 99% fine with your method. 

I would suspect the high copper concentration is causing the chocolate coloration but I've never used copper to inquart. However, I've seen that dark brown from nitric digestions of high copper silver alloys. If you have sufficient palladium it may be the reason as well. 

Do you have any DMG to test it with?


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## Harold_V (Oct 14, 2011)

4metals may be on the right track. I've been away from refining for a long time, when white gold typically contained nickel, but I understand white alloys of today commonly contain palladium. The results are a very dark brown solution, although with a high percentage of copper present I'd expect that it would more likely be a dark brown/green color. 

There isn't likely to be much silver, if any at all, in white gold that is alloyed here in the States. Our friend, Nick, from the UK, recently enlightened me that 9K white gold, there, does contain silver, however, so it's hard to say what to expect. A simple test or two would certainly answer any questions. 

On the subject of testing, assuming there's palladium present, a test of the nitric acid solution should reveal its presence, even with stannous chloride. The presence or absence of silver could be easily determined by simply testing a drop of solution with a grain of table salt. 

Harold


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## Oropolis.com.mx (Oct 14, 2011)

Thank you very much for your reply, so basically what you are telling me is that i should inquart with silver instead of copper am i right? here in mexico it is no problem to buy nitric acid but i just want to make my refining as clear as possible so if i have to change to inquart with silver that is no problem with me. 

thank you very muvh

Regards, 


Mario 
Oropolis.com.mx 


4metals said:


> I do not know how difficult it is to get nitric acid in Mexico but in the US a lot of our members have trouble getting it. For this reason you would be better off using silver to inquart because silver will dissolve in 1/3 the quantity of acid. But in addition, any platinum or palladium in your scrap will be collected with the silver for you to recover. Silver used to inquart and collect by cementation can be used over and over again. If you are processing white gold, there is a chance some palladium is in the alloy.
> 
> You should be able to recover about 22 grams of silver from your spent acid the way you are doing it now so it would only be a matter of time until you collect enough silver to use it instead of copper.
> 
> ...


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## Oropolis.com.mx (Oct 14, 2011)

thank you very much Harold for your advice, i have 20 buckets containing blue nitric acid, and i have been recovering the silver from there , but some of the recovered silver is like a white paste, can you help me in recovering the white silver paste?


Harold_V said:


> 4metals may be on the right track. I've been away from refining for a long time, when white gold typically contained nickel, but I understand white alloys of today commonly contain palladium. The results are a very dark brown solution, although with a high percentage of copper present I'd expect that it would more likely be a dark brown/green color.
> 
> There isn't likely to be much silver, if any at all, in white gold that is alloyed here in the States. Our friend, Nick, from the UK, recently enlightened me that 9K white gold, there, does contain silver, however, so it's hard to say what to expect. A simple test or two would certainly answer any questions.
> 
> ...


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## Juan Manuel Arcos Frank (Oct 14, 2011)

Mario:

Chocolate solution is a colloidal solution,when gold jewelry contains tin(almost always as welding) then the problem begins.

To destroy the chocolate solution you must add concentrated sulphuric acid(read about H2SO4 safe handling) and boil for an hour,this causes to break down colloidal solution and gold precipitates.Try to avoid tin.

White paste is silver chloride,you can recover silver from it following Karo syrup process or cementation process with aluminum,iron or zinc .Keep us posted about your progress.

Bienvenido al Foro,Mario.

Kindest Regards.

Manuel


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## Oropolis.com.mx (Oct 14, 2011)

Muchas Gracias Manuel!
i have sulphuric acid here so i will start the chocolate recovery process and i will let you know.
for the white cemented silver i will have to have more details if you could help me because i have a lot of it.

un abrazo!

thank you for your help, 4metals, Harold v and Manuel, you really helped me a lot, and i will be posting my progress with the chocolate acid recovery.

Thanks Again!


Juan Manuel Arcos Frank said:


> Mario:
> 
> Chocolate solution is a colloidal solution,when gold jewelry contains tin(almost always as welding) then the problem begins.
> 
> ...


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## Palladium (Oct 14, 2011)

Sam has a guide on inquarting on his site. http://goldnscrap.com/index.php?option=com_content&view=article&id=67:refining-karat-gold-and-silver-jewelry-using-inquarting-method-part-1&catid=25:scrap-gold-9k-24k&Itemid=20

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=8147&p=76056&hilit=+silver+chloride+conversion+karo#p76056

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=6215&p=54669&hilit=+silver+chloride+conversion+karo#p54669


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## 4metals (Oct 14, 2011)

If tin is an issue, I don't think it will be in large quantities and using copper to cement your silver out of the filtered nitric will drop your values and leave your solution with all of the base metals. 

Treating your white paste, which is likely silver chloride if you were processing jewelry is easily done with corn syrup and caustic. The key to complete conversion is good mixing and I have found a tumbler made for 5 gallon buckets works well for this and can process up to 100 ounces per batch using the syrup and caustic 

http://www.miim.com/thebside/tumbler/index.html


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## Juan Manuel Arcos Frank (Oct 15, 2011)

Mario:

INDEED!!!!!....this exactly what this wonderful Forum is for!!!!,look,I am posting for you a method(in Spanish) to convert silver chloride(white mud) to metallic silver using iron nails.

We live pretty close(200 km) and I travel frequently to Puebla,we can run the process together,if you want.Of course,there is a price to pay: Here is my price:some beer,some tequila and mole poblano(mole poblano=traditional food of Puebla,it is a kind of chocolate and chili sauce,brown colored,served with tortillas,beans and rice)

Kindest regards.

Manuel


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## Oropolis.com.mx (Oct 17, 2011)

Hello Manuel, 

but of course i will invite to you here to eat some mole poblano, tequila, and beer!!!!!!!! please let me know when you are coming to Puebla so we can meet.

un abrazo 


Mario Gonzalez
Oropolis.com.mx



Juan Manuel Arcos Frank said:


> Mario:
> 
> INDEED!!!!!....this exactly what this wonderful Forum is for!!!!,look,I am posting for you a method(in Spanish) to convert silver chloride(white mud) to metallic silver using iron nails.
> 
> ...


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