# Hydrocholoric + Nitric + H202



## Gold-Digger (Apr 20, 2007)

I've purchased and read several different reports including information listed on this site about using Muratic (HCl Acid) + Nitric and or H2O2 (Hydrogen Peroxide) for removing gold off pins and CPU's. 

I am trying about 5 different batches of this stuff in an attempt to find a good recipe. One batch that has me baffled is using the following mix:

1 part HCL (33% Muratic)
4 part distilled Water
1 Tablespoon of Sodium Nitrate (for Nitric Acid)
1 part H2O2 (3% peroxide)

In this solution I have several CPU's. After 2 days the pins are just gone but there appears to be no gold in the solution which has now turned a greenish color. So I wonder if this solution has dissolved the gold?

I'm guessing some of the more experienced gold refiners will know. Will a solution of HCL, Nitric and H202 dissolve gold into solution? 

And is there any mix of chemicals I should be using to remove gold from pins and CPU's instead of this mix considering I don't want to use something like Aqua Regina due to fumes.


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## Noxx (Apr 20, 2007)

Nitric Acid and HCl will form Aqua Regia wich is a very strong acid. It is able to dissolve gold. I don't know what H2O2 is used for in this case...


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## Fever (Apr 20, 2007)

Yes, you are inadvertantly creating Aqua Regia with your recipe, and it is dissolving your gold into solution. Not sure how the H2O2 is affecting things, as it is usually used in combination with HCL alone. Don't fret, you should be able to precipitate your gold from the solution and refine from there.

Fever


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## AgAuPtRh (Apr 20, 2007)

Gold-digger

I may be wrong. But I believe what you are mixing is Aqua Regia. Not your standard mix of Reagent grade acids -- but Aqua Regia non the less. Aqua Regia Light maybe. But it will dissolve "everything" even the gold. Save all of your solutions do not store them indoors -- the fumes and vapors can cause some serious damage.

Your gold is in the solution and will have to be dropped out. But with the chems you have in there now I'm not sure that the process I am familiar with will work for you. 

Hang in there and be safe.


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## goldsilverpro (Apr 20, 2007)

Although the solution is very weak, it has all the ingredients necessary to dissolve gold. If the gold was there to start with and it's not there now, it has to be in the solution. Gold chloride produces a yellow solution but, there's a lot more copper than gold. Therefore, the blue green copper color is overpowering the yellow gold. Also, blue-green plus yellow makes greener blue-green. 

If you have stannous chloride, you could put a couple of drops on a filter paper or spot plate, add a couple of small crystals of stannous chloride and then a drop of water. Purple or black shows gold.

Put some solution in a very clear glass, put a piece of white paper behind it so you can see the colors, and look for yellow at the very top fringe of the solution level next to the paper. Use good lighting. If you see yellow, there most probably is gold present. About the only other thing that produces yellow is iron but, not at the fringe. If the solution is in a white container, such as a white bucket, you can also see the yellow fringe, no matter how dark the solution.


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## Gold-Digger (Apr 20, 2007)

O.K. that explains everything..................

The good news is this small but weak batch of aqua regina I accidently made has dissolved the gold over a 2 day period without any major fumes. I have it stored outside but cannot smell anything unless I move the jar up near my face. 

Now I need to figure out the best way to get out the gold.


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## lazersteve (Apr 20, 2007)

Gold-Digger,

You've managed to dissolve your gold using two methods at the same time. :?: :!: It's a waste of chemicals to do it this way. You should stick with the standard solutions and get the procedure down before 'mixing it up' and trying odd cocktails of chemicals, you might accidentally create something you don't want to be handling. Even after you get familiar with the standard procedures please, for your own safety, don't randomly mix methods . You should never try unknown formulas without first consulting someone with a good chemical background or hands on experience with the mixture(s) you are trying. This forum should be your first line of defense when it comes to your safety and mixing chemicals. This goes for everyone here. If you haven't ever tried a particular experiment ask for suggestions BEFORE moving forward with your idea. No one here wants to see anyone injured or worse because they didn't ask a few simple questions first. There are no stupid questions!

You can drop your dissolved gold as usual. Be sure to test the solution with stannous chloride before disposing.


Steve


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## goldsilverpro (Apr 20, 2007)

That was interesting. By the time I made my post, there were other posts already made. What was great was that everybody had the same correct answer, but all from a little different aspect..


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## daveerf (Apr 21, 2007)

Heya Gold-Digger, 

I hate to sound redundant but like Steve said "Safety First". It's fun to experiment but please read Materials Safety Data Sheets on chemicals and information on mixed chemicals or check in this forum about safety. Never and I repeat NEVER put your nose up to a jar of mixed acids and dissolving metals to see if it smells or is letting off fumes, especially of Aqua Regia (Nitric and Hydrochoric). Chlorine gas and a host of other byproducts from these processes can be dangerous and possibly lethal. I appreciate your bravery but like Steve said we want to enjoy your company and posts for a long time to come.


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## goldsilverpro (Apr 22, 2007)

If you do have a compelling urge to smell any solution, here's a safer way to do it. Don't put your nose over the container. Always put your head off to one side and use your hand to fan a little bit of the fumes or odors to your nose. Don't ask me how I learned this.


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## Gold-Digger (Apr 22, 2007)

Thanks for the pointers. I was doing a simple mix of recipes and made them weak. The last thing I want to make is something lethal but I've seen quite a few acid mixes before including HCL and Nitric and H2O2, etc. I have experience with some nasty and lethal acids but using this stuff for gold etching is new science to me.

Many metals are etched by Nitric or HCl but will build up barriers such as oxides. A mix can really break these down sometimes. 

Anyway I've finished my little experiment and have a solution which seems to work. See one of my other posts about gold floating in solution... I think the word is 'Eureka'. 

Also, yes I learned the hand technique to smell fumes in Organic Chemistry years ago. But with most of these acid solutions there's no need for that. Just get within a few feet and you'll pick up a wiff.. ha!!


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## [email protected] (Sep 3, 2021)

Yes you have dissolve the gold you can tell because of the light greenish color your mixture turned is the gold has been dissolved in order to read precipitate the gold you need to add either sodium metabisulfite or the quadratic precipitant you can buy from ishor.com. once you add percipitant, heat the solution to about a hundred and eight degrees F for about 15-20 minutes then let sit for a couple hours come back and you'll have your muddy gold sludge in the bottom that's your gold. you want to filter that out with 2 coffee filters together or 3 even, and then let it dry then you put it in a Bruno Crucible and heat and it will get that to a gold color and look like gold once again with that


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