Hcl + Cl produced gold foils

[ItsaboutROI]

So in attempting to refine some gold filled jewelry by using the HCL + CL method I ended up with gold foils. I was attempting to just dissolve all of the metals including most of the base metals thereby allowing the gold to re-cement back to the little bit of Base metal that was left and was not dissolved by the original amount of HCL + CL. I was leaving it overnight before I went to bed this is what it looked like see photo...



I thought the gold was supposed to dissolve and cement back onto the remaining base metals in black powdery form? Instead of dissolving it just came off in the form of gold foils as you see in the picture I haven't checked it yet today I'm going to check it shortly. But I'm assuming that all of those foils should have dissolved and re cemented back to the base metals?

 

[anachronism]

To be honest with you.

Firstly you're looking to recover the gold from the gold filled- the refining comes later. Secondly HCl/bleach isn't suitable for anything more than foils. That's covered pretty well on most threads here.

If you're looking at the process that utilises gold being dissolved then precipitated onto your base metals in a loop scenario then you need to be using AR. That's aggressive enough to do this, but that process is quite advanced because you need to understand the theory behind it completely to avoid losses.

I'd honestly recommend more reading and learning so you understand the whys and wherefores in a much clearer way.

Hope that provides some clear information and assistance.

Jon

 

[ItsaboutROI]

To the contrary I remember HCL + Bleach is described opposite from what you are saying. HCL + hydrogen peroxide is to get the foils. HCL + CL will dissolve everything via the creation of chlorine gas in solution. I thought the HCL + CL was poor mans AR? I know i have read on here as well as in the books that hcl + cl will dissolve gold making Au chloride?

 

[Shark]

I have to agree with Jon here. If you want to recover a small amount of gold filled, and can't get nitric acid, I would try using poorman's nitric to recover the gold foils, and foils is used very loosely here as gold filled will leave a lot thicker foil than fingers will. Thick enough to not be a good candidate for the HCl/Cl process. You may even use full AR, but as mentioned, you need a good idea of what is going on and how to deal with it. My first attempt was a nightmare.

As an example last week I used AR on a smallish batch of gold filled and came up short on the amount of gold expected. Took a day or two but I found it, another 3.7 grams. I will not let that much of a loss go without figuring out what went wrong.

Following commonly recommended advice of the forum is handy for many reasons. Often that simple advice, is also the easiest to recover from any mistakes, and helps those offering the help an easier way to figure out how to advise you.

Even then, if you want to try an off method, it is a good idea to ask the forum first than try to clean it up later. With that said, don't feel like your the only one to need help, we have all been there.

Stannous test your solution. If negative, decant the solution, add your remains to enough AR to put 100% of it into solution. Stannous test, just to be sure, filter perfectly clear with NO particles still floating around, drop it with a precipitant that works better with a dirty solution. Stannous test to be sure you got it all. Decant the powders and do a wash cycle. edited to add...after a wash cycle it is not a bad idea to stannous test your wash solutions. Depending on how clean you want your gold, be prepared to do it all over again.

 

[FrugalRefiner]

ItsaboutROI, you're getting your various processes a little confused.

HCl + hydrogen peroxide is most often used to dissolve the copper base metal under gold foils like the fingers from RAM and other computer add-on cards. It is sometimes also used to dissolve the base metal of pins.

HCl + bleach is most often used to dissolve the gold foils left from the process above. It is usually only used on very thin metal foils like those from fingers, or on powders like those from a sulfuric stripping cell or when re-refining gold after a first drop. In use, the chlorine gas that is released uses up some of the HCl, and the NaOH used to stabilize the bleach neutralizes more of the HCl, so as you're using it, you're losing HCl. It definitely has its limitations.

Poor man's AR is HCl plus a nitrate slat like sodium nitrate or potassium nitrate. It is not HCl plus bleach.

The poor man's nitric that Shark mentions is a combination of a nitrate salt as mentioned above, but mixed with sulfuric acid rather than HCl.

So, yes, HCl plus bleach will dissolve gold and create gold chloride, but it's not a great choice for what you tried to do. It probably did dissolve some gold at first, and that gold probably did cement out on remaining base metals. So you probably have a combination of base metals in solution, gold foils, gold that has cemented back out of solution, and remaining solid base metals. You could probably test the solution to be sure it's barren, decant it and treat it as waste, and continue the process with fresh acid, but it's going to be a laborious process.

HCl plus peroxide or poor man's nitric would probably be a better choice to dissolve the base metals away, then dissolve the gold. Or go with poor man's AR, or true AR in the process you were attempting.

Dave

 

[ItsaboutROI]

ItsaboutROI, you're getting your various processes a little confused.

HCl + hydrogen peroxide is most often used to dissolve the copper base metal under gold foils like the fingers from RAM and other computer add-on cards. It is sometimes also used to dissolve the base metal of pins.

HCl + bleach is most often used to dissolve the gold foils left from the process above. It is usually only used on very thin metal foils like those from fingers, or on powders like those from a sulfuric stripping cell or when re-refining gold after a first drop. In use, the chlorine gas that is released uses up some of the HCl, and the NaOH used to stabilize the bleach neutralizes more of the HCl, so as you're using it, you're losing HCl. It definitely has its limitations.

Poor man's AR is HCl plus a nitrate slat like sodium nitrate or potassium nitrate. It is not HCl plus bleach.

The poor man's nitric that Shark mentions is a combination of a nitrate salt as mentioned above, but mixed with sulfuric acid rather than HCl.

So, yes, HCl plus bleach will dissolve gold and create gold chloride, but it's not a great choice for what you tried to do. It probably did dissolve some gold at first, and that gold probably did cement out on remaining base metals. So you probably have a combination of base metals in solution, gold foils, gold that has cemented back out of solution, and remaining solid base metals. You could probably test the solution to be sure it's barren, decant it and treat it as waste, and continue the process with fresh acid, but it's going to be a laborious process.

HCl plus peroxide or poor man's nitric would probably be a better choice to dissolve the base metals away, then dissolve the gold. Or go with poor man's AR, or true AR in the process you were attempting.

Dave

Thanks for clarifying this. Your explanation really shed light on the details and grew my understanding .

Ah Man! Well It's not a total loss i still got everything there. Now i know that hcl + cl only dissolves the thin plating on electronics (not military grade of 300 micro inch -1500 micro inch I would assume). So truthfully i only want to remove the gold i don't need to refine it to pure I just need to get it off the base metals. So should i just soak the gold filled in hcl + hydrogen peroxide next time? I'm wondering if the hcl & hydrogen peroxide will reach and dissolve all the base metals inside the gold layer coating the base metals?