Easy to make etching solution, a different kind of AP

[NobleMetalWorks]

I couldn't find any information about this on the forum. If I am posting something that has been posted before, I apologize.

I am interested in more environmentally safe ways of processing material. I am curious if anyone has experience with this recipe.

Vinegar – Distilled White Vinegar – diluted with water to 5% acidity
Peroxide – 3% solution
Salt - Added until reaction fizzes on it's own.

The Vinegar helps in the oxidation and reduction of Cu

H2O2 causes Cu to create Cu2

Salt provides Cl ions that react with Cu2 to produce CuCl2, this removes Cu2 and drives the reaction.

When the solution turns blueish, more NaCl (salt) should be added until the blue clears and there is fizzing action, the blue color is Cu2. The more blue the color, the more Cu2.

I was playing around with this a few weeks ago but I haven't taken it any further. Here are my questions.

Does this formula create any gases besides Hydrogen, that can be harmful?

How would you reduce Cu2+ to Cu?

How can this solution be safely and responsibly disposed of? After Cu2+ is removed, I imagine the resulting solution would be mostly benign? Am I correct in assuming this? I am planning on making a perm AP tank based on this solution, with air diffusers to see if I can keep the solution going just by simply adding salt as needed to drive the reaction forward.

Surprising the solution works fairly quickly. It dissolves copper fairly readily.

Any advice, input or other information would be greatly appreciated.

Thanks

Scott

 

[Geo]

dissolved copper is considered toxic waste. the copper would have to be removed before disposal. this can be done with steel. cementing copper on steel will work in any copper chloride solution as far as i know. after the copper is removed, the solution can then be neutralized and discarded. iron is not considered toxic and as long as the solution is PH neutral, you can dispose of it in the environment as long as no other heavy metals are present.

 

[NobleMetalWorks]

When salt is added, the Cu2 would precipitate CuCl2, when it's dried out it takes on a bluish/greenish color.

If I was going to dispose of the solution, instead of renewing it, what would be the best way to cement out the Cu2, I'm okay with the CuCl2.

Thank you for the reply Geo. I appreciate it.

Scott

 

[Geo]

make sure the solution is at least slightly acidic. test the PH, if its 4.5 or lower, you shouldnt have any trouble cementing the copper out.its an ionic exchange. your swapping iron for copper in solution.

 

[NobleMetalWorks]

make sure the solution is at least slightly acidic. test the PH, if its 4.5 or lower, you shouldnt have any trouble cementing the copper out.its an ionic exchange. your swapping iron for copper in solution.

Right, so if it's not acidic enough, if my experiment failed and I needed to get rid of the solution, I would just make it acidic, then cement everything out with Iron, then add Sodium Hydroxide to precipitate iron, resulting in salt water, then dispose of it.

Thanks...

 

[Shaul]

I also came across this information, by accident. Here's a link to the article where I found it.
http://www.stephenhobley.com/blog/2011/03/02/still-messing-with-forces-i-dont-understand-the-formula/
Interestingly, he starts off talking about standard AP with added salt, but then the rest of it is about the H2O2, vinegar and salt.

Scott;
Did you do anything further with this idea?
Will it work for fingers and other similar material?
Will the addition of salt speed up the AP process?
Can H2O2, vinegar and salt be considered a viable alternative to standard AP?

Any help would be appreciated.

Shaul

 

[solar_plasma]

Copper acetate will decompose at 240 °C and vinegar can be distilled off (german wikipedia: Kupferacetat).

Two things are not clear for me: I don't know, where the vinegar gets the missing hydrogen from and what will be left over, Cu or CuO. H2O would solve both questions, but there will not be any H2O at 240°C at 1 atm pressure....maybe some of the CH3COO- would form CO2 and H2O, which could be the answer. Maybe a chemist likes to tell?

I would only do this, if I am sure, there is only copper. If there is nickel present, I would expect very poisonous vapors.

 

[924T]

NobleMetalWorks,

Somewhere in this forum is an old prospector's formula that uses vinegar, salt, and a shot of Povidone
Iodine, that was used right in the panning bowl.

The Gold was dissolved, and then precipitated using vitamin C.

Even though this sounds like refining, when I ran across your etching solution thread, and saw vinegar
in use, I immediately thought of the prospector's formula.

Whether for etching or refining, I'm all for a reasonably priced acid (vinegar) that's safe to use!

Cheers,

Mike