# Can I use AP solution for AR



## zamistro (Nov 21, 2009)

I'd like to try poor mans AR now that I've tried AP. Is it possible to use the leftover AP with the peroxide in it? It is emerald green.

Conversely, I'd like to reduce the volume of the leftover AP by boiling and leave it for another time. But the only vessel I have big enough is stainless steel. What could I add to neutralize the HCl?


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## Anonymous (Nov 21, 2009)

HCl and the used AP solution will dissolve stainless. You need to evaporate in a big flat plastic or glass container.
I do not know, but, I think using used AP solution for Poor Mans AR does not sound like a good idea to me.
Used AP is pretty decent for removing iron and aluminum from electronic scrap.

Jim


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## dick b (Nov 21, 2009)

Why not put it back into a plastic 1 gal container like the one that the HCL came in, or a 5gal plastic pail just like HD and walmart sells. You can buy Plastic lids to cover it. You can also put it into 1 gal glass jars with a plastic screw on lid. Save it and reuse it!
dickb


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## butcher (Nov 21, 2009)

Zamistro, acid peroxide can be used over and over, it can also besaved as is or concentrated and stored, when using you will need additions of ingrediants.

if you wish to dispose of I would first hang a piece of copper in it to replace any possible values, decant, then hang some steel (aluminum can be used),to precipitate copper from solution (I use electrolisis faster not nessary), decant solution from copper powder, (this iron solution I evaporate down to save chemical, not nessary), now we have an acidic Iron or aluminum chloride, neutralize the acid with caustic soda (lye) sodium hydroxide, or baking soda,wood ash, or other alkali, decant metal powders, now I add lime and evaporate to dry.

I have took old acid peroxide and evaporated to thick brown syrup where crystals form, (this was past the point where clorine boils off, so if you don't want to boil off too much chlorine do not concentrate this far down), then used this later after storing by adding some HCl and peroxide, water depending on peroxide strength.

look for lasersteve, and others have some excellent posts on dealing with waste issues.


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## zamistro (Nov 23, 2009)

Thanks. I went with what most people seem to be saying and put a chunk of copper in my 3.5 (or so) gallons of AP. Correct me if I'm wrong, but this is supposed to turn my green solution brown or black and cause any gold present to precipitate out. Would adding more peroxide help the process?


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## lazersteve (Nov 23, 2009)

zamistro said:


> Thanks. I went with what most people seem to be saying and put a chunk of copper in my 3.5 (or so) gallons of AP. Correct me if I'm wrong, but this is supposed to turn my green solution brown or black and cause any gold present to precipitate out. Would adding more peroxide help the process?




Peroxide will oxidize the solution back to the reactive state and dissolve the gold again as long as there is free acid in the mix. Adding a chunk of copper will turn the solution dark and cement any PMs out. 

Steve


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## zamistro (Nov 24, 2009)

Thanks Steve. A few more things so I'm clear:

1. The copper bar is supposed react with any remaining HCl thereby neutralizing the mixture. Right?

2. About how long should it take with 3.5 gallons of AP?

3. When I last checked on the copper bar a drop of the solution fell on the concrete floor and fizzed. Does this mean there is still free acid?

4. When you say "cement PMs" does that mean it will adhere to the copper or fall to the bottom?


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## lazersteve (Nov 24, 2009)

zamistro said:


> 1. The copper bar is supposed react with any remaining HCl thereby neutralizing the mixture. Right?


The copper displaces the precious metals in the solution. A little free acid helps get the ball rolling.



zamistro said:


> 2. About how long should it take with 3.5 gallons of AP?


Until the soluiton is dark colored (brown or black), usually 24 hours or less.



zamistro said:


> 3. When I last checked on the copper bar a drop of the solution fell on the concrete floor and fizzed. Does this mean there is still free acid?


That's most likely the acid reacting with the concrete.



zamistro said:


> 4. When you say "cement PMs" does that mean it will adhere to the copper or fall to the bottom?


The precipitate consistency depends on several factors like concentration, pH, and temperature. 

Steve


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## Platdigger (Nov 24, 2009)

I might add, if you have a lot of free acid...it will disolve a lot of copper.


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## butcher (Nov 25, 2009)

copper will not neutralize the acid. as steve's explained it will use any acid that is in excess (the acid is negative, the metal's are positive, these join to make salts of metals, like copper metal and cloride from your HCL), Cu+ + Cl- gives copper chloride salt in solution.

base is opposite of an acid, a base will neutralize an acid,

ACID HCL (muratic acid) and BASE NaOH (sodium hydroxide, caustic soda), notice one is acid and the other is base, both are dangerous to our skin, and can burn us, but if these were mixed in proper perportion they will make a salt of the metal (sodium), in fact they make table salt, H+CL- + Na+OH- ---> NaCl + H20
notice the hydrogen positive wants to join with the hydroxide (OH) negative to make water, and that leaves the positive metal sodium to join with the chloride negative to make a table salt water solution.
the table salt will be close to neutral PH, not an acid, and not a base.


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## Oz (Nov 25, 2009)

Another way of looking at it is that if you have 70% nitric and you put copper in it there comes the point that the solution is saturated with copper and no more can be dissolved. This does not mean that all of the acid has been consumed, just that you have reached the saturation point. If you add some water to the solution at this point it reduces the copper concentration in solution and additional copper can now be dissolved without adding more acid.


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## EVO-AU (Nov 30, 2009)

Okay Guys: Am I to assume that if I put Cu into an AP solution it will neutralize the acid ? I used two gallons of sodium hydroxide the other day to eliminate 1 pint of hcl in my AP solution. Interesting, it also dropped the Au.

Phill


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## butcher (Dec 1, 2009)

Adding metal is not neutralizing the acidity of the acid, it will form salt's of that metal and acid, and if there is free acid in solution (not joined to the metal) it will dissolve as much metal as it can for that concentration and temperature, this is dependent on if the metal used will be attacked by the acid used, also another metal higher in reactive series can replace the previous metal from this acidic metal-salt solution, when I say salt I am talking about the metal and acid, Example: zink and sulfuric acid would make a zink sulfate salt in acidic solution, and if we added magnesium it would displace the zink, precipitating it from the acidic. solution as the acidic solution dissolves the magnesium making a new acidic salt solution of magnesium sulfate, I am under the impression the PH (percent Hydrogen) does not change too much.

Adding a Base Like NaOH(sodium Hydroxide) to an acid changes it's PH (percent Hydrogen) thus destroying the acid.
The Hydrogen is what makes the acid.
the OH- (hydroxide)is negative from the base, and then H+ (Hydrogen) from the acid is positive these two opposites are just waiting to become water HOH or (H2O), notice one of the Hydrogen's came from the acid, this lower's the acids PH (percent Hydrogen).

adding sodium hydroxide to an acidic metal salt solution not only lowers its acidity (PH) taking the hydrogen from the acid and making water in solution, but also can make some metals to convert to oxides, and can lower the acidity of the solutions these metals need to stay dissolved in solution,which now is closer to water.

I am no chemist and have only begun to learn,and may understand things different, not having formal education, and have a hard time explaining things, 
so other's please join in with additions and correction's, I need the education.


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## EVO-AU (Dec 11, 2009)

Butcher: On Nov 22, you posted something about using Cu to replace some metals. Will Cu neutralize acid in an A/R or A/p solution ? Phill


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## Anonymous (Dec 11, 2009)

Metals that are attacked by acids like HCL are replacing the hydrogen in solution giving off hydrogen gas. That is why copper is not readily attacked by HCL since copper does not replace hydrogen because hydrogen is more active than copper. Also, although magnesium is supposed to replace zinc and precipate it out, it most likely will not do that in a water based solution because as soon as the zinc is formed it can replace the hydrogen in water most likely forming zinc hydroxide.

Jim


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## EVO-AU (Dec 14, 2009)

James: Okay, that sounds viable. Not being a chemist ( an ex-wire pusher, like you ) it seems you do a lot of study on these things.k I will do some research. Thanks, Phlll


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