# Reuse my old AP?



## taylorwilbeck (Oct 26, 2011)

In Lasersteve's videos on AP he mentions that he can "Reactivate" his old AP solution by adding Peroxide or by bubbling. Does his mean I should save my used AP waste solution and the next time I have fingers just put them in my old AP after peroxide has been added?
Thanks


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## philddreamer (Oct 26, 2011)

Yes. Filter the solution & use an aquarium pump & a bubble stone. Or just the hose... or add peroxide. This will rejuvenate the AP solution.
Do a search & you'll find a lot of information on the subject.

Take care & be safe!

Phil


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## Geo (Oct 26, 2011)

when the solution becomes totally saturated it looks brown and kind of thick. place in a different container and place a piece of steel in the solution, a large enough piece that it wont fall apart in this process.after several days the solution will clear to a very light green color with copper and other metals precipitated in the bottom. the solution has now been converted from copper chloride to ferrous chloride.filter this metal out of your solution and let everything in the solution settle for a few hours.carefully decant solution back into your AP container and start over again.

edited to change ferric chloride to ferrous chloride.


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## Claudie (Oct 26, 2011)

Before you add the steel to the solution, it is a good idea to let the solution sit for a couple of days to let any solids that may be present, settle to the bottom. Then you can siphon the solution off, saving the solids, which will contain any precious metals that you may have missed before.


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## philddreamer (Oct 26, 2011)

I prefer to add the steel when I'm completely done with the AP solution. I feel that as long as the solution is saturated with copper when ever I use it, any PM's, lower in the series that might dissolve, will tend to cement & their recovery would be much easier. 
And yes, I let the solution sit for several days if not weeks. I'm in the process of recovering PM's from solutions that've been sitting for months after adding clean copper. I had some gold drop out of the first batch.

Phil


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## Geo (Oct 26, 2011)

i too let my solution sit for long periods but someone else may not have the space to let many containers sit or may have other reasons not to have containers of extra chemicals sitting around.the process i described will clear the liquid in a couple of days and be ready to use rather quickly as apposed to letting sit for extended periods.


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## maek1 (Nov 23, 2011)

This may sound like a dumb question , can i use stump out to drop gold from my used watered down ap solution ?


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## Geo (Nov 23, 2011)

did you test with stannous chloride to make sure theres gold in solution.


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## butcher (Nov 23, 2011)

maek1,
If the stump out is sodium pyrosulfite (sodium metabisulfite) (SMB) it will precipitate gold.

Some brands of stump removers are potassium nitrate; they will not work to precipitate gold. Check the MSDS of the brand you have.

There is no reason to use SMB to precipitate the gold from your used acid peroxide solution (copper chloride solution), as adding this to the next batch (copper-plated gold ) will make any gold in solution cement out, and adding copper buss bar would be a better method to get any gold to cement out, and keep solution healthy for reuse.

I do not purposely add Iron to my used copper chloride solution unless it is to dissolve iron from say a iron plated with gold, or I am trying to cement copper out of solution for disposal of the solution.

Geo's method in his post above makes an Iron chloride (this would not be my preferred method if I was going to reuse the copper chloride solution), this would be a good step when in preparing the solution for disposal.

Geo do not take my comment wrong here: but my feeling for you to tell a new member to add Iron to regenerate his acid peroxide (copper chloride) is not a good Idea, Laser Steve has spent much time teaching the forum members how to do it the best way possible, (He also provides documents on his website which new members should be encouraged to read) to keep the acid peroxide (copper chloride) in best condition for reuse, here your telling them to make Iron chloride out of it (which will also dissolve copper, but it is not the same thing) copper chloride is easier to regenerate than iron chloride is), Steve has some good documents on his website please read them.

This part is hard to explain: I do reuse my old solution's (not only copper chloride) so many times and for lower grade scrap (dissolving base metals, and many times it does get loaded with metals above copper and becomes an Iron chloride solution (which will dissolve copper and other base metals), but this dirty solution is not used for cleaner scrap, but used to dissolve metals higher in the reactivity series than the solution holds.

Understanding how the copper chloride solution works, will help you use it, learning how to regenerate it properly and get any values from it, what it can do when and why, Laser Steve has valuable documents on his website that will help with this, he has also made many many posts helping others to understand, also read the forum posts on this subject, there is enough info there to fill a book.

Understanding the reactivity series of metals, will also help you understand more and will be a huge help to your skills in this trade, spend some time researching this subject on the intranet.


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## Geo (Nov 23, 2011)

no offence taken. here is the source of the information i was citing. http://www.artmondo.net/printworks/articles/ferric.htm . ferric chloride is the chemical used to etch new printed boards due to safety concerns.i am definitely not trying to upstage steve in any way as i have the utmost respect for him.converting copper chloride to ferric chloride doesn't diminish its effectiveness on converting copper to copper chloride (if im reading this right) ferric chloride and oxygen should work and will convert copper and oxygen to copper chloride.you may need to add a little fresh hcl but you would do that anyway.


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## butcher (Nov 23, 2011)

Geo,
I am well aware of the document you provided and the procedure, and chemistry involved.

But many new members are not, and will run into trouble with the ferric hydroxide formed (which is a slightly soluble contaminate), also the insoluble Iron compounds formed mixed in the solids (which may hold values), they may not know how to deal with.

Geo you give real good advice, and help many new members, but every once in a blue moon, I see something that you state that I feel needs some clarification (many new guy's may not understand what you have learned).

Also Iron in the reactivity series will not only cement copper, but also many other metals like Cd, Co, Ni, Sn, Pb, Sb, As, Bi, Cu, and our values (now of course silver, lead, mercury and copper I Chloride are insoluble, as well as the hydroxides of iron formed). 

Keep up the good work, helping others here.


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## dscrapper (Nov 29, 2014)

where is everyone getting their steel to use when the a/p is dark in color. what are you using ? thanks


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## Geo (Nov 29, 2014)

dscrapper said:


> where is everyone getting their steel to use when the a/p is dark in color. what are you using ? thanks



Any piece of light steel will work.


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## jason_recliner (Nov 29, 2014)

Assuming the steel is to commence with disposal of your AP, and not to rejuvenate it, any scrap steel will do.
A shelf bracket. A piece of computer case. Even a can of tuna. Eat the tuna first.

A single solid piece is preferable because you can remove the excess steel easily, when you are ready to proceed to dropping the iron for disposal. Don't be like me who threw in a handful of steel sandblasting grit, which works fast but you can't remove it.

If you want to reuse your AP, you're probably on the wrong track with steel. A section of railway track, mind you, would be superb.


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## Lane5625 (Feb 7, 2015)

Is there a recommended amount of peroxide to AP to clean it for reuse?


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## Pantherlikher (Feb 8, 2015)

Lane5625
You do not use peroxide to clean A/P
Peroxide is used to supply O2 to be used to dissolve copper.

Using an air bubbler is better to keep the reaction going.

When I first put HCL and gold plated scrap in my bucket, I poured a splash of peroxide in it.
Splash, tad more then a drop but less then a pour...To give you an idea. Only some to start the process.
Once copper begins to dissolve, it uses O2 supplied from air pumped into the solution.
I use a small Fish aquarium pump with a bubbler. 

Now, I put the peroxide back in the medicine cabinet. Since it's winter and I am not doing anything, the A/P bucket is sitting covered and waiting untill temps warm up and I will only add plated scrap and HCL and turn on the air pump.
A/P can do allot of copper before it gets so saturated that it will not do more. Light greenish precipitate, goo, will form on the bottom.

When this happens, I pour off allot of liquid. A/P gets fresh HCL and air and goes like crazy. The liquid poured off goes into the waste stream I have set up. Gold plated steel in first which dissolves steel, dropping copper and gold flakes. Then on down the system until it reaches the PH adjustment bucket for final treatments. See Waste disposal 

B.S.


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## Geo (Feb 9, 2015)

jason_recliner said:


> Assuming the steel is to commence with disposal of your AP, and not to rejuvenate it, any scrap steel will do.
> A shelf bracket. A piece of computer case. Even a can of tuna. Eat the tuna first.
> 
> A single solid piece is preferable because you can remove the excess steel easily, when you are ready to proceed to dropping the iron for disposal. Don't be like me who threw in a handful of steel sandblasting grit, which works fast but you can't remove it.
> ...



Treatment with iron is the end of AP. "AP" as we call it here is actually copper(II) chloride solution. Once you remove the copper by replacing it with iron, it will be ferrous chloride. You can then take the ferrous chloride and heat it and by adding oxygen through H2O2 or bubbling pure oxygen through it, it will create ferric chloride. If you use pure oxygen, the solution will be more concentrated. By heating AP while bubbling pure oxygen through it, you will get a self perpetuating reaction where the copper chloride is depleted at around the same rate as the ferrous chloride is being made and the ferric chloride is depleted creating copper chloride. Things like electronics are consumed quickly. 

This discussion was about disposal. Treating old AP solution with iron is one of the final steps for rendering it safe for disposal.


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## jason_recliner (Feb 10, 2015)

Geo said:


> Treatment with iron is the end of AP. "AP" as we call it here is actually copper(II) chloride solution.


Agreed. Once you put iron in it, it might be reusable if you add heat and pure oxygen as you say. I don't know much about ferric chloride except that I used it to etch copper as a kid.

With all due respect to your greater experience, that's not AP anymore. Since the original question was about reusing AP, not about disposing of it, I think it's inferred that it would still be copper(II) chloride, rather than something entirely different.


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## Geo (Feb 10, 2015)

The very first time you use the solution to dissolve anything other than copper it becomes a mixture of different metal salts. Any one that uses it regularly will learn that unless you only do fingers, the solution eventually turns black. Of course this is all academic for those that have never used it. Some of the terms we accept and use all the time is not really false but are somewhat inaccurate. Without getting into the chemistry (because I suck at chemistry) all I can say is, use it until you can't use it any more. It will live until it dies. Metal salts is sometimes a very strange animal. Even the metal salts that are not copper will act like copper does when the metal is in a molten state. Metals that are lower on the reactivity series of metals will cement metals from their salts that are higher. Metal salts that are lower in the reactivity series of metals will dissolve metals that are higher. We use copper because it is as low as you can get without getting into precious metal salts. Copper is listed as a noble metal.

You can re-use the AP solution for as long as it will dissolve metal. Depending on how you care for it. Adding oxygen cleans the solution of higher metals by oxidizing the salts. Most metal oxides will not dissolve easily. The oxides will deposit at the bottom of the container as solids. This will not remove all of the contamination but does make a big difference.

edited for clarity.


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## francis32 (Jun 2, 2015)

The plates I have inside AP are a 2" x 6" ceramic base, layer of copper and a fine plating of gold on both sides. They are used in high heat high power application, made by Semikron in Germany. On one side they seem to have some small steel wire contacts that I scrap off before putting into AP. There is some solder where the wires were that has a higher melting point than lead solder (silver??) 

Anyway, the AP has been started with HCL and H2O2 at a 5 to 1 respectively and pure Cu buss bar immersed to start the Cu2Cl leeching. Bubbles are keeping it alive and it is dissolving slowly but surely. They are kept in a glass pickle jar since the small gold particles tend to stick to plastic. 

Silver if any should be absord in the Cu2Cl solution and not on the dark gold mud filtered out of the AP? Copper buss bar immersion only insures all the gold has fallen out from Cu2Cl, doesn't drop silver like it would in aqua regia right?

Sorry if I'm on the wrong thread.

Thanks
Francis


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## goldsilverpro (Jun 2, 2015)

Silver won't dissolve in AP solution.


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## francis32 (Jun 2, 2015)

Thanks for answering GSP,

is silver having the same reaction as in AR(passivates??) 

then after washes with hcl and then addition of HCL/clorox to form auric chlorides from the sediments, silver then should be absorbed or will stay in the filtration process?

thanks again, I have been reading here for a while but never posted

Francis


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## Evan2468WDWA (Jun 2, 2015)

I saw an interesting video recently. I was wondering if the process could be used on AP solution.

https://www.youtube.com/watch?v=FjEoRidvgYE


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## goldsilverpro (Jun 2, 2015)

francis32 said:


> Thanks for answering GSP,
> 
> is silver having the same reaction as in AR(passivates??)
> 
> ...



I wouldn't call it passivation. The common ingredient in both AP and AR is a lot of the chloride ion, Cl-, from the HCl. If you were to happen to dissolve some silver, the combination of silver ion, Ag+, and Cl- ion would immediately occur and form the compound AgCl, which will not re-dissolve in acid chloride solutions (except ever so slightly in strong AR solutions). 

For practical purposes, in the acid Cl- system, silver can only exist in the form of silver metal or AgCl, both of which are solids. Very little, if any, will dissolve. So little, it's hard to measure it without specialized equipment.


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## g_axelsson (Jun 3, 2015)

Silver solubility numbers in various solvents and temperatures.
http://www.saltlakemetals.com/Solubility_Of_Silver_Chloride.htm

Göran


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## g_axelsson (Jun 3, 2015)

Evan2468WDWA said:


> I saw an interesting video recently. I was wondering if the process could be used on AP solution.
> 
> https://www.youtube.com/watch?v=FjEoRidvgYE


Very interesting and something I might try on my copper chloride wastes. Thanks for sharing.

Spoiler alert :

- Old copper chloride etchant -> Distill off hydrochloric acid for reuse.
- Convert into copper sulfate by adding sulfuric acid -> Distill off hydrochloric acid for reuse.
- Remove copper via electrowinning, produces copper and sulfuric acid
- Filter off copper and distill sulfuric acid to reuse

No wastes produced, sulfuric acid can be reused in the process, copper can be reused, recycled or discarded safely.

I wonder how this process would work on dirty copper chloride? It's not uncommon to get lead, tin, zinc and iron in the etchant unless you only run very clean cut fingers.

Göran


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## francis32 (Jun 3, 2015)

I have a question concerning this from Pantherlikher : "The liquid poured off goes into the waste stream I have set up. Gold plated steel in first which dissolves steel, dropping copper and gold flakes"

Doesn't it make it harder at the end to mix copper + gold ,then needing to dissolve copper again to separate from Au? 

After all gold has dropped from the solution with copper immersed for weeks, I've used hard drive covers with labels and seals removed, screw holes are a plus, a few of them together to accelarate the process, cut in half since my beaker was small , also with all of them holding with a stainless wire (copper wire or plastic should work fine too) and copper cemented to it within hours (trying to attach pictures, first time) they were used several times before deteriorating and I have lots of those lying around in my steel scrap pile.

The copper in the bottom of the depleted AP was minimal (pour off solution) the solution now has has a light emerald green tint, very clear.

Kept the plates in water to keep them for future use.


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## francis32 (Jun 3, 2015)

Before neutralizing with Limestone as intructed by Lasersteve, this "ferrous chloride/ferric chloride (if O2 is added) seems to eat flatpacks(IC's) pins quite well before pyrolysis is done on those IC's. 

Just saying, we should use the max of acid before its retirement, the recuperation with lab equipment by distillation as intructed by Nurdrage is not always available to all.

Francis


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## nickton (Apr 22, 2019)

Distilling apparatuses are VERY nice to have. I got one from china for about $35.00 (I think) on Ebay. One of my best investments for sure. 

Thanks for that link. I can do it all except for the platinum anode needed at the end. I also am not happy about bubbling for long periods of time to convert copper 2 to 1...but... 

Great video from Nurdrage. 


Also: thanks for the hard drive cover picture. Didn't realize they were copper--or is that just copper cemented onto Stainless{?}. I hear some people put a stainless steel fork or something in there too. :mrgreen:

Hope I'm on the right page.


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## Davmeek20 (Dec 16, 2019)

butcher said:


> maek1,
> If the stump out is sodium pyrosulfite (sodium metabisulfite) (SMB) it will precipitate gold.
> 
> Some brands of stump removers are potassium nitrate; they will not work to precipitate gold. Check the MSDS of the brand you have.
> ...


 
That was a great answer. I like how i was just reading and learning and learned exactly how and who made this site. And where to find info. I love reading this forum when i get stuck. Thanks butcher!!


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## Davmeek20 (Dec 16, 2019)

That was a great answer. I like how i was just reading and learning and learned exactly how and who made this site. And where to find info. I love reading this forum when i get stuck. Thanks butcher!!


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