# Reuse of HCL



## edj1963 (Jan 31, 2008)

Hello,

Can I reuse The HCL + peroxide from my copper recovery tank?

The Acid has lost most of its "green" can I siphon and add more peroxide to process more foils? is there a end of life for the hcl?

Thanks


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## Lino1406 (Feb 1, 2008)

What actions you did for "copper recovery"?


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## edj1963 (Feb 1, 2008)

Steel immersion causes the copper to plate out as sponge on the steel. Good way to use up some case parts  


Note: any one feel free to correct my terminology if incorrect.


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## OMG (Feb 1, 2008)

I'm working on an acid regeneration technique, one one way I'm going to try is bubbling SO2 through CuCl2.
2CuCl2 + SO2 + 2H20 -> 2CuCl + 2HCl + H2SO4
so.. by oxidizing the dissolved copper with sulfur dioxide, you get HCl and sulfuric acid.


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## Lino1406 (Feb 2, 2008)

1. According to Ed, the HCl is weak and
more Fe solution than HCl. Are you sure
you still want to reuse it? 
2.OMG - it seems you put more money
in than you get out.


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## Irons (Feb 2, 2008)

OMG said:


> I'm working on an acid regeneration technique, one one way I'm going to try is bubbling SO2 through CuCl2.
> 2CuCl2 + SO2 + 2H20 -> 2CuCl + 2HCl + H2SO4
> so.. by oxidizing the dissolved copper with sulfur dioxide, you get HCl and sulfuric acid.



or Sodium Metabisulfite will precipitate the nearly insoluble CuCl as a whitish powder which can be filtered out and recycled. Using SO2 is a little better because it doesn't neutralize any of the acid or add Sodium Ions.
It all depend if you want to recover the Copper or regenerate the acid. For recovering the Copper, Sodium Sulfite is preferred.
You can generate SO2 by burning Sulfur in Oxygen or Air or heating Sodium Metabisulfite to 190 deg C. which leaves Na2O as a residue.


Everything but the squeal.


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## lazersteve (Feb 2, 2008)

Ed said:


> Can I reuse The HCL + peroxide from my copper recovery tank?



Yes, bubble air thru the mix until the color becomes a clear transparent green color (about 24 hours). Adding more peroxide will accomplish the same goal.

The HCl is not what dissolves the copper in this reaction it's the copper chloride. If you add iron, steel, aluminum, etc. you will remove the copper as stated and the solution will no longer be useful as AP.

Steve


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## skyline27 (Feb 2, 2008)

Would it be effective to bubble air through the AP while you are stripping the gold?

At what point does the solution become too saturated with base metals to be effective?


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## lazersteve (Feb 2, 2008)

Skyline,

Bubbling air thru the AP solution as it etches speeds things up a bit, but it tends to spit and splatter everywhere, so cover the bucket with a loose fitting lid.

The solution merely grows in volume as it consumes more base metals. The copper chloride formed is the dissolving agent and is recycled when oxidized. Saturation can occur when the solution has absorbed more copper than the volume of liquid will hold. Adding a bit of HCl, water, or peroxide will activate it again. Which one to add and how much is determined by several factors.

The details of what to add when are in a Copper Chloride document on my website, http://www.goldrecovery.us which anyone interested in the AP reaction should study throughly. It seems all to often people are asking questions here when the answers have previously been accumulated and provided here and/or on my website, but they refuse to read the documents provided.

Study your reactions and documentation throughly before you begin to use them and it will serve you far better than any outside assistance. Who knows maybe you can even figure out a something that will make the reaction work better.

Steve


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## Anonymous (Feb 6, 2008)

I have clean, dried, filtered 125 PSI compressed air at my disposal.
Is this ok to use in my AP?
I have a low pressure regulator (5 PSI Max) coupled with an adjustable flow meter (3 CFM Max) that prevents splatter from excess flow/pressure.
Or is it better to use an aquarium pump because of the air properties?
Thanks,
Ideal-Wirenut


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## lazersteve (Feb 6, 2008)

Wirenut,

I have only tried an ordinary aquarium pump. It wouldn't hurt to try other sources of air and let the forum know your results.

Steve


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## OMG (Feb 29, 2008)

What happens when you put aluminum into your copper and iron chloride solution?
I tried it, assuming it would release HCl and H2, so I bubbled the stuff through a column of water to try to dissolve the HCl.

It didn't work as far as I can tell. I dont think any/much HCl gas got dissolved into the water. Although all the metals are at the bottom of the container and the liquid is pretty much clear, so the chlorides had to go somewhere.

Anyone know what this reaction does? Its got to be making aluminum chloride, and aluminum chloride is very reactive with water.. supposidly stealing the oxygen from h20 and releasing HCl(gas).

The metal chlorides I had were very concentrated, and I think some HCl was produced but not much... So what happened to the chlorine if it didn't go up in gas?


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## Irons (Feb 29, 2008)

Only use as much acid as needed to do the job and you won't have a bunch to dispose of later.

It can be distilled off fairly easily and recovered.

When the HCL has boiled off, put the remaining salts in your stock pot.

Everything but the squeal.


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## Irons (Mar 1, 2008)

Hydrochloric Acid is a solution of Hydrogen Chloride gas in Water. You have to start off with some distilled Water in the receiving flask to absorb the HCL gas that is distilled off of the salts solution. Be sure the receiving flask is cold, preferably in an ice bath.


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## Anonymous (Mar 17, 2008)

I have clean, dried, filtered 125 PSI compressed air at my disposal. 
Is this ok to use in my AP? 
I have a low pressure regulator (5 PSI Max) coupled with an adjustable flow meter (3 CFM Max) that prevents splatter from excess flow/pressure. 
Or is it better to use an aquarium pump because of the air properties? 
Thanks, 
Ideal-Wirenut



lazersteve said:


> Wirenut,
> 
> I have only tried an ordinary aquarium pump. It wouldn't hurt to try other sources of air and let the forum know your results.
> 
> Steve



Finally got back to working on this.
Used compressed air from a screw compressor that has been filtered, sent thru a dessacant air dryer chamber, & then thru a freon refrigerent air dryer.
Took about 3 days to change a used quart of AP from a dark green to a bright emerald or jade colored clear green.
Will pick up an cheap used aquarium pump when garage sale season starts up to compare it to.
Ideal-Wirenut


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## Palladium (Nov 25, 2008)

8)


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## wop1969 (Mar 25, 2009)

about this subject and using zinc to precip everything, I did it today on a small scale for fun and zinc worked Excellent, here are the befor and after pictures. I took the picture a little late in the game so keep in mind the befor pic was dark green like the flask next to it.


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## Anonymous (Apr 3, 2009)

Yes Zinc the way to go.......


Keith


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## Harold_V (Apr 4, 2009)

gold1961 said:


> Yes Zinc the way to go.......


Depends on your objective, really. If you are trying to recover from a batch gone bad, zinc will do that, but if are looking for selective precipitation, zinc is a loser. 

You can accomplish the same thing with scrap steel, which is far easier and cheaper to procure. I suggest keeping zinc for those cases where it is needed. Precipitating values from cyanide, for one.

Harold


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## wop1969 (Apr 6, 2009)

Harold_V said:


> gold1961 said:
> 
> 
> > Yes Zinc the way to go.......
> ...


Harold is right on the money(as Ushual)
I posted the pics just to share but that method is not the way to reuse AP as stated by steve that you do not want to remove everything to regenerate it.



Lazersteve said:


> The HCl is not what dissolves the copper in this reaction it's the copper chloride.
> If you add iron, steel, aluminum, etc. you will remove the copper as stated and the solution will no longer be useful as AP.



So if I am undestanding this putting copper in AP creates CuCl and that is what keeps the reaction going?


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## Oz (Apr 6, 2009)

It is the copper that does the work in AP. Steve has a PDF on his site that will tell you more than you probably want to know about it.


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## lazersteve (Apr 7, 2009)

The AP reaction should really be called the Copper II Chloride reaction as this is the active ingredient. 

Insoluble Copper I Chloride builds up and causes the dark brown color and off white to gray colored salts in the gold foils. Bubbling air or adding a small amount of hydrogen peroxide in the presence of HCl will convert the CuCl into reactive CuCl2 (Copper I Chloride to Copper II Chloride).

Steve


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## wop1969 (Apr 7, 2009)

Oz said:


> It is the copper that does the work in AP. Steve has a PDF on his site that will tell you more than you probably want to know about it.




I read it oz Just like you said , that is the only way I am starting to understand the AP proccess even enough to attempt to make the statement i did



Wop said:


> So if I am undestanding this putting copper in AP creates CuCl and that is what keeps the reaction going?



What I should have said:So if I am undestanding this putting copper in AP creates CuCL2 and that is what keeps the reaction going when "steve said:you bubble air in it or ad peroxide to it" you regenerate it.

Babysteps


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## steveonmars (Apr 25, 2009)

I have some AP solution that is very dark green. I add more peroxide and it keeps right on working but I've now got so much copper that any gold in solution is dropping out into a brown powder. I'm adding this to the foils to redissolve in HCL/Cl later. I started a new batch of AP.

To regenerate the old batch do I remove the copper (after testing for gold is negative) by placing some scrap steel in the bucket and then when the copper is gone do I just add more peroxide to rejuvinate the solution?

Thanks,

Steve


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## Anonymous (Apr 25, 2009)

No once you take the copper out it is done, I know there is a ferric cloride type compound use to ecth pc boards but I do not know if the ferric chloride resulting from adding iron to the spent ap can be converted to it or not.

jim


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## steveonmars (Apr 25, 2009)

Does that mean I don't need to remove the copper at all? Just siphon off the liquid once in a while to get the gold that precips and add more peroxide?

I looked again and the color is almost a dark brown now instead of green. For the price of a gallon of HCL should I just start a new batch when it gets like this. I'm running 100's of cell phone boards right now which have a lot of copper so it's getting used up fairly quick.

Steve


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