# My first AP, check my math?



## Captobvious (Feb 26, 2013)

Hey guys, just started my first AP process on a batch of fingers. Now according to everything I've read (Hokes, here, and elsewhere) the math for AP is 4:1 HCL to H2O2 yes? This batch of fingers was probably around 5 lbs (digital scale is on order) I have them in a 2 Gallon bucket (with strainer holes drilled in the bottom and about a 1/3 of the way up the sides) inside of a 5 gallon bucket. I applied 2 gallons of HCL and 8 cups of H2O2 (16 cups to a gallon) and have a 10 gallon fish aquarium air pump applying constant air to the mix. I also added a couple of copper heatsinks to get the reaction started. Now I'm assuming that the reaction I got after applying the H2O2 was normal but not sure because everything I've seen and read on the AP method is that the liquid should be green. That said when I applied the H2O2 to the HCL it immediately turned a bright yellow color. After monitoring it for about 15 mins the color did start to change to a more muddy greenish yellow color so again unless someone more experienced tells me otherwise I'll just assume this is normal for a fresh batch of AP.... but is it normal?


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## butcher (Feb 26, 2013)

Captobvious

I am not sure about your math, it does sound like more peroxide than I would use in the beginning, also it should only be 3% hydrogen peroxide and 97% water, (more concentrated like 30% would put gold into solution with other metals), these fingers were they trimmed from the rest of the memory? If you put in whole memory you would end up with a mess caused from tin in the solder, and if you put gold into solution with tin it would cause lose of gold in colloidial solution, the yellow could have been gold dissolving, which you do not want to happen, if your peroxide was not too strong it would form black powder as the copper replaced gold in solution, and even if you used strong peroxide the copper heat sinks would probably be plated with gold, problem here is if this is what happened you would now have to dissolve the heat sinks to get all of your gold back, (too much or especially too strong of a peroxide will put gold into solution), No reason to add copper like copper heat sinks to the batch, all that is going to do is use up HCl and peroxide to dissolve that copper, there was already enough copper in the close cut memory fingers to make the copper chloride solution.

Sounds to me like you made at least a little mistake, but we need more details, to see if it could be more of a big mistake.

The copper heat sinks were a mistake (which may not be too bad, unless the hydrogen peroxide was too strong).
How strong was the hydrogen peroxide used?
Were the memory fingers trimmed from the rest of the memory circuit board, so only gold plated copper was added to solution, and so no that solder was introduced in solution?


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## Captobvious (Feb 26, 2013)

butcher said:


> Captobvious
> 
> I am not sure about your math, it does sound like more peroxide than I would use in the beginning, also it should only be 3% hydrogen peroxide and 97% water, (more concentrated like 30% would put gold into solution with other metals), these fingers were they trimmed from the rest of the memory? If you put in whole memory you would end up with a mess caused from tin in the solder, and if you put gold into solution with tin it would cause lose of gold in colloidial solution, the yellow could have been gold dissolving, which you do not want to happen, if your peroxide was not too strong it would form black powder as the copper replaced gold in solution, and even if you used strong peroxide the copper heat sinks would probably be plated with gold, problem here is if this is what happened you would now have to dissolve the heat sinks to get all of your gold back, (too much or especially too strong of a peroxide will put gold into solution), No reason to add copper like copper heat sinks to the batch, all that is going to do is use up HCl and peroxide to dissolve that copper, there was already enough copper in the close cut memory fingers to make the copper chloride solution.
> 
> ...



My apologies for missing a few details, I used 2 gallons 32% muriatic acid and 1/2 gallon (8 cups) 3% Peroxide. All fingers were as closely trimmed as I could get with hand shears but yes all trimmed. I want to link to the thread here but, but in it, it was recommended to put a little copper into a fresh batch of AP to get the reaction started hence the heatsinks, if it was an unnecesary step I'll just not do that in the future. Also I checked this morning and it was a nice emerald green color but I didn't have time (running late for work) to pull the inner bucket out to investigate further.


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## FrugalRefiner (Feb 26, 2013)

Captobvious said:


> I want to link to the thread here but, but in it, it was recommended to put a little copper into a fresh batch of AP to get the reaction started hence the heatsinks, if it was an unnecesary step I'll just not do that in the future. Also I checked this morning and it was a nice emerald green color but I didn't have time (running late for work) to pull the inner bucket out to investigate further.


Captain,

The AP process is actually a copper II chloride etching process. HCl doesn't do a very good job of dissolving copper, but it will dissolve oxidized copper. If you simply put clean copper into HCl, it won't do much. When you add hydrogen peroxide, the H2O2 oxidizes the surface of the copper, and the HCl can then dissolve it. So the H2O2 simply "kick starts" the reaction. Copper II chloride is capable of dissolving metalic copper, so once you have some in your solution that's what keeps the reaction going.

The problem that can happen when starting a fresh batch of AP is that the H2O2 can also dissolve some of your gold into solution, especially if you use a lot or if it's a high percentage H2O2. You will eventually recover this gold as the solution becomes saturated with copper, as the dissolved gold will cement out of solution and be replaced with copper, a more reactive metal. But it will be a fine black powder among the other solids found in the bottom of the AP bucket instead of nice big flakes.

This is why some people start a fresh batch of AP with a little copper _before_ they add their gold bearing feedstock. It ensures that the H2O2 is consumed digesting copper, not their gold. Once the H2O2 is consumed, the copper II chloride will only digest copper, not gold.

Now that you have a batch going, you won't have to worry about it in the future. The AP is reusable, so you can just recycle it for future batches.

Dave


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## Captobvious (Feb 26, 2013)

FrugalRefiner said:


> This is why some people start a fresh batch of AP with a little copper _before_ they add their gold bearing feedstock. It ensures that the H2O2 is consumed digesting copper, not their gold. Once the H2O2 is consumed, the copper II chloride will only digest copper, not gold.
> 
> Now that you have a batch going, you won't have to worry about it in the future. The AP is reusable, so you can just recycle it for future batches.
> 
> Dave



Ok cool, I had a feeling I skipped a step, this would apparently be it  but at least any that got dissolved is still there so no loss yay 

I'll try to post some pics tonight if I have time


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## Captobvious (Feb 26, 2013)

Think there's something wrong.... when I came home from work and finally got time to check on things this is what I found....







Much clearer than I had anticipated, but the smell of HCL was still quite strong and the couple drops that spilled on the floor fizzled as normal on the concrete, so I don't think it's lost it's acidity






Again not what I expected, mind you it's been less than 24 hrs since I set this up but I would expect the heatsink to be gone by now at least /confused











Once I lifted and dropped the bucket a few times the mix got much darker, almost black. Keep in mind this is Omaha and it's an uninsulated garage I'm working out of and it's anywhere from 20 deg to 40 deg F so I guess that could be slowing things down.

Would you guys recommend leaving it alone to bubble (had to reposition the air line so it would hold at the bottom as it was floating on top when I checked on it a few minutes ago), add more HCL (don't think this is it as the acid is still fairly strong although I have no way to test just yet as I wasn't expecting to have to PH balance this process just yet), or add more H202?

Please feel free to laugh, cry, whatever, just be honest please


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## Geo (Feb 26, 2013)

im confused, or should i say, your confused. please tell us why you have a large piece of copper in your AP solution. that is copper, right? maybe you misunderstood the directions when using AP to strip foils.

point being, you do not need to add copper. theres plenty of it under the gold foils.


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## Captobvious (Feb 26, 2013)

Geo said:


> im confused, or should i say, your confused. please tell us why you have a large piece of copper in your AP solution. that is copper, right? maybe you misunderstood the directions when using AP to strip foils.
> 
> point being, you do not need to add copper. theres plenty of it under the gold foils.



That was the earlier mentioned copper heatsink I used to start the reaction last night, it has since been removed when I went to check on things tonight.


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## kkmonte (Feb 26, 2013)

Your muriatic acid that you are using, its not the "safe for the environment" stuff is it? I've been doing my fingers in my barn which has been in the same 20-40 range you speak of, it adds a little bit of time but with the bubbler, that should almost negate that. That is a real lot of fingers (5 lbs) in one batch so you are going to need to agitate/shake up the fingers every so often to get the ones in the middle to go out and play with the acid. When you pull the bucket in and out of the water that will mix up all of the acid/peroxide, etc. 

I also found it best that I just drop my bubbler in the inside bucket (the stone goes an inch or so under the acid) and let it bubble inside with the fingers. I tried putting it underneath the inside bucket and that never worked well for me.

Ken


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## Geo (Feb 26, 2013)

i may be wrong but i think Dave meant to just have copper chloride solution to start the process and not necessarily to add a piece of copper with the fingers. if you dont have any pregnant leach, you can make some by dissolving a piece of copper in AP solution. by adding the copper with the fingers, it may deplete the hcl before the process is finished OR saturate the solution with copper which will cause copper(I) chloride to precipitate.


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## Pantherlikher (Feb 26, 2013)

Hi...
Looking good as long as copper bus bar is out and rinsed...
Now most important part ya'll be a missin... 
PATIENCE...please...
Agitate in the AM before work... and often when you get home and feel impatient... lift..let settle back, lift, let settle back... And look for Gold specks...
All ya can do is wait...
My guess is you over done did it a tad with Peroxide as I've been reading to add alittle at a time untill color change...but no problem there either...

BS.
If patience was worth it's weight in gold, we'd all be broke...


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## Captobvious (Feb 26, 2013)

kkmonte said:


> Your muriatic acid that you are using, its not the "safe for the environment" stuff is it? I've been doing my fingers in my barn which has been in the same 20-40 range you speak of, it adds a little bit of time but with the bubbler, that should almost negate that. That is a real lot of fingers (5 lbs) in one batch so you are going to need to agitate/shake up the fingers every so often to get the ones in the middle to go out and play with the acid. When you pull the bucket in and out of the water that will mix up all of the acid/peroxide, etc.
> 
> I also found it best that I just drop my bubbler in the inside bucket (the stone goes an inch or so under the acid) and let it bubble inside with the fingers. I tried putting it underneath the inside bucket and that never worked well for me.
> 
> Ken



Ken, I know for sure it wasn't the "safe" muriatic as I've seen that discussed here before as being impure, if anyone remembers the deal Home Depot had a month ago for the 2 pack of 1 gallon containers that's what I'm using. Would you recommend reducing the mount of fingers I have in there for now?



> Geo said:
> 
> 
> > i may be wrong but i think Dave meant to just have copper chloride solution to start the process and not necessarily to add a piece of copper with the fingers. if you dont have any pregnant leach, you can make some by dissolving a piece of copper in AP solution. by adding the copper with the fingers, it may deplete the hcl before the process is finished OR saturate the solution with copper which will cause copper(I) chloride to precipitate.



Correct, the Copper was intended to merely start the reaction and as I was running late for work this morning I didn't have time to remove it until tonight. Admittedly I tried to unintentionally shortcut things by mixing it all with the fingers in place, and then became paranoid I was going to be dissolving gold before the reaction could get started so I tossed the copper in to get things going.



Pantherlikher said:


> Hi...
> Looking good as long as copper bus bar is out and rinsed...
> Now most important part ya'll be a missin...
> PATIENCE...please...
> ...



That's kind of what I was thinking too, I mainly wanted to make sure and double-check here as I don't recall ever seeing an AP mix that was that clear before in pics/vids I've seen. I just checked on it a little while ago and it was no longer the dark color in the last pics but again that very light green color in the first pic.... although as stated I've not seen a fresh/early batch, but only ones that have been bubbling for a few days or so.


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## Captobvious (Feb 26, 2013)

Also when I checked on it last night before I went to bed the reaction was going strong, dark green color, bubbling away, and the vapor/bucket/liquid was noticeably warm. This morning and tonight they were at ambient temps.

Also I feel I have not been totally honest as I was a bit embarrassed that this happened (feel free to mock me I deserve it) but when I initially put in the copper last night at the time I could only find heat-sink that was half copper half aluminum. When I put that in the reaction was quite violent, lots of fuming, acid became incredibly agitated from the reaction. I immediately pulled that out but I do worry that the reaction with the Aluminum may have had an adverse reaction to the mix. Yes I feel stupid, yes feel free to laugh.


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## kkmonte (Feb 26, 2013)

I'm LOL'ing right now!  It's funny, when I was reading your post, the thought crossed my mine "Hey I wonder if he put in a heat sink with aluminum on it", although i'm still a newb so I don't know what that would do to the reaction, etc.


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## jmdlcar (Feb 26, 2013)

Is the brand you using the Smart brand is the you want? Cause they sell two kinds of Muriatic Acid.

Jack


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## Captobvious (Feb 26, 2013)

Note to self... get Muriatic from Lowes from now on (the jug on the left) and not the Homely Despot... turns out the two pack was the "smart" variety *bangs head on desk repeatedly* The thing is I distinctly remember looking out for the "Smart" type, found an open box of the 2 packs (only had one jug in it so I didn't grab that box), and it wasn't the Smart brand and nothing mentioning it on the box... I'm feeling real stupid now.... does Home Depot have two types they may have in a two pack box that looks the same from the box?

Welcome to the Captobvious comedy hour! Hope you enjoyed the show


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## Geo (Feb 26, 2013)

20° Baume is what your looking for. really, thats all that matters. ive used the green label for AP and it worked just fine. its the "safer" brand from Lowe's. the brand name is unimportant as long as its 20° Baume.


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## Captobvious (Feb 27, 2013)

Geo said:


> 20° Baume is what your looking for. really, thats all that matters. ive used the green label for AP and it worked just fine. its the "safer" brand from Lowe's. the brand name is unimportant as long as its 20° Baume.



Ok so the HCL is good to go then? All 3 bottles are 31.5% 20 deg Baume. Any thoughts on if the Aluminum would have ruined the batch even if it was for a very brief time?


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## Geo (Feb 27, 2013)

aluminum would have neutralized hcl much, much faster than copper and would have cemented the copper out of your solution for a short time but in all, i doubt it had much ill effect on it. it should be just fine. do try to keep the aluminum out of you solutions unless you want to cement base metal and/or generate alot of heat.


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## kkmonte (Feb 27, 2013)

I've used the HCL on the left before from Lowes, seems to work OK, I then went to a small mom and pop hardware store and got some other good name brand that doesn't have "safe" anywhere on the bottle. I told the guy I want your most dangerous HCL you have!


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## Captobvious (Feb 27, 2013)

So I guess the lesson I need to take away from this is to be patient eh? Good to know 

I'll keep this updated as the week progresses so that in a year from now I can laugh at myself :lol:


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## bswartzwelder (Feb 27, 2013)

The last batch of printed circuit boards I did had no components (ever attached from the factory). I started the air pump added the HCl and H2O2 and let it work. I have a lid on the outer bucket with a brick on it to keep other things out like rain. Left it undisturbed for about 2 weeks and when I came back, everything was stripped and ready to continue processing. I do not us an airstone in the bottom of the bucket. I run the airline tubing from left to righ, then back. From there, I run the airline tubing north and south. I tie the airline tubing to the bottom of the bucket and punch holes every inch or two with the end of a paper clip heated with a lighter. I also heat the end of the tubing and crimp it shut. Worked like a charm. Very little stuff around here works really fast, so be patient. Sounds like you're on the right path. Good luck.


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## jmdlcar (Feb 27, 2013)

Captobvious,

First off I don't want make you mad and if I do SORRY. If I had about 5 pounds of fingers and it was your first time with AP I wouldn't have did 5 pounds the first time it would have a lot less to learn how then go full speed. I hope for you everything works out. If I ever get a lot of scrap I will only do a pound or less at a time for a while then I will do more. 

The fingers I have did I use 2 cups of 31.45% Muriatic Acid (Smart brand) and less then 1 ounce of 3% hydrogen peroxide (Wal-Mart) and that was 8 ounces of fingers cause that all I had.

You have a good day and always work and be safe cause you only have 1 life to live.

Thanks
Jack


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## Captobvious (Feb 27, 2013)

jmdlcar said:


> Captobvious,
> 
> First off I don't want make you mad and if I do SORRY. If I had about 5 pounds of fingers and it was your first time with AP I wouldn't have did 5 pounds the first time it would have a lot less to learn how then go full speed. I hope for you everything works out. If I ever get a lot of scrap I will only do a pound or less at a time for a while then I will do more.
> 
> ...



Nah we're cool everyone learns different, some of us learn in harder ways than others.  Personally I tend to go all in when it comes to projects of mine, sometimes it's a blessing, other times it's a curse :lol:


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## Captobvious (Feb 28, 2013)

nothing new to report, day 3 and no change, liquid still very clear(barely a green tint unless agitated then it goes dark for a short while until it settles again), no flakes appear to have come off the fingers.... thinking about adding some more 3% H202 tomorrow when I get paid. Also considering in addition to that removing about half or more of the fingers from the AP.

Thoughts?

-edit- I haven't decanted the current mix into another bucket yet to check for salts/foils yet, and probably won't at this point until next week when my dentist can make this tooth stop throbbing... put simply I don't trust myself in the garage lab until I'm no longer jacked to the hilt with Vicodin just to be able to not be in agony.


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## Captobvious (Mar 1, 2013)

Day 4, all I can say is W00T! Solution is a much more normal AP green color upon opening the bucket and without agitating, upon pulling the inner bucket to inspect it, it became obvious that things were beginning to work. Some fingers were bare, others were starting to flake off, so I'm thinking I'll just leave things well enough alone for a few days aside from stirring the fingers. :mrgreen:


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## Captobvious (Mar 4, 2013)

Day 7







There's still a lot of gold on the fingers, this is just going sooo much slower than I anticipated. If this was your batch what would you do at this point?


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## kkmonte (Mar 4, 2013)

I'd keep my bubbler going with the fingers, maybe just put back half of the fingers to do at once, and agitate it as often as I could.


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## butcher (Mar 4, 2013)

Give us some pictures of the solution in a jar, looking at it maybe we can tell something by the color. it should be a lighter green if very dark or almost brown it may need more oxygen, I do not see white salts of copper I chloride with your gold so I guess you are OK on HCl, speaking of HCl are you using regular HCl or that new green stuff?
How cold is it where you copper II chloride leach is at night and days? If it is very cold the leach slows down, it will work but very slowly, you can heat it if you wish, Or just let it work and wait, you can build a box for the bucket to sit in with a light bulb in the box, if you do this you must build it to be fire safe, and electrically safe, and make it so it will not overheat anything, a thermostat can be added if you wished, there are several other ways you can heat the solution a little, somewhere around 80 degrees would be enough heat. Pumping air in with a fish tank air pump and small hose with the end plugged and small cuts in the tubing or holes drilled with a hot wire, will not only supply air but can help to circulate the solution. Patience is a lesson you will need to learn in recovery and refining. Gold is a very patient metal it takes patience to get.


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## Captobvious (Mar 4, 2013)

Butcher, is pretty much AP Green from what I can tell

Using the cheap (10 gallon rated but was the smallest I could find lol) fish tank airpump I got from the pet store





and with the pump off





Not sure if that answers the color question or not...

Your questions on temperature make me believe the slow recovery is being caused by that more than anything. Temperatures around here this past week were around 30-35F for the highs and 10's to 20's for overnight lows, I'm working out of an uninsulated garage so add maybe 5 deg when the sun's beating down on the room helping out, plus no wind...


Holy crap I can't wait for Spring to finally get here! I really don't want to buy yet another tank of propane for the garage heater (already gone thru 4 of them this winter)


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## butcher (Mar 4, 2013)

It is hard to tell from the picture but it looks too dark, it should be a light green color so you can see through it easier, when it has enough oxygen it is a lighter green and clearer, it looks like using a little 3% peroxide, and warming it up a little will help speed it up. 
If you have a whole bucket of fingers your trying to dissolve a lot of copper, if the solution darkens when saturated with copper I chloride dissolved in solution, the reaction slows down, you want it to be copper II chloride, no reason to heat a whole shop to get one bucket warmed up a little, the light bulb and a box is not the only way to warm it up, but probably a little easier than other methods. 

It is hard enough for the solution to undermine the gold plating, warming and a healthy copper II chloride solution should speed it up a little, it is normally a slow process but from what you have stated your is just much more slower than it should be. The bubbles I can see is stirring the solution that is good, I do not know if you have many small bubbles that leave more oxygen in solution, or large bubbles that just pass through solution so fast trying to get to the surface that they are leaving little oxygen dissolve in the liquid.


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## Captobvious (Mar 4, 2013)

butcher said:


> It is hard to tell from the picture but it looks too dark, it should be a light green color so you can see through it easier, when it has enough oxygen it is a lighter green and clearer, it looks like using a little 3% peroxide, and warming it up a little will help speed it up.
> If you have a whole bucket of fingers your trying to dissolve a lot of copper, if the solution darkens when saturated with copper I chloride dissolved in solution, the reaction slows down, you want it to be copper II chloride, no reason to heat a whole shop to get one bucket warmed up a little, the light bulb and a box is not the only way to warm it up, but probably a little easier than other methods.
> 
> It is hard enough for the solution to undermine the gold plating, warming and a healthy copper II chloride solution should speed it up a little, it is normally a slow process but from what you have stated your is just much more slower than it should be. The bubbles I can see is stirring the solution that is good, I do not know if you have many small bubbles that leave more oxygen in solution, or large bubbles that just pass through solution so fast trying to get to the surface that they are leaving little oxygen dissolve in the liquid.



I'm planning on when I get a chance to get a fresh hose line for the air pump to do the coil method in the bottom of the bucket. Basically as I understood it, you seal off the end of the hose going into the bucket, then pierce the line with a pin every inch or sofor a couple feet of line, coil that int he bottom of the bucket and then you have instead of the one end bubbling up hard, you have 50 or so ends bubbling up.

I'll put in another cup of Peroxide and see how that goes as you suggest and hopefully that'll speed things up a tad.

Thanks for the input


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## Captobvious (Mar 4, 2013)

Ok so I added another cup of 3% H202, I removed a sample to check color, and yes it seems very dark






To give a little better perspective on just how dark green it has gotten here is the inner bucket pulled up just enough to keep the fingers about a little under an inch under the surface of the mix.






Given what you say about a dark mix needing 02 or more peroxide to lighten things up I'll let is settle for a bit after adding the previously mentioned cup of peroxide and if there's no change I'll add another cup and proceed from there.

Unless someone has a better idea that is


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## jmdlcar (Mar 4, 2013)

Hi,

When I use peroxide 3% I use very little just enough to get the process started. Here is how I do fingers and I found this in a message written by Steve and I add some.



> As a learning process you can process a few hundred grams of finger boards in a quart sized mason jar. Make sure the fingers are trimmed close with minimal green board along the cut edge and no tiny spare parts or pins on the boards!
> 
> Do this in a well ventilated area away from metals items that can corrode easily.
> 
> ...



Jack


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## Captobvious (Mar 5, 2013)

Just a follow-up to adding that cup of Peroxide last night. It definately seems to have helped, as when I stirred the mix tonight the surface of the mix immediately became covered in gold flake and upon inspection of the fingers noticed many of them laid bare or were half bare... so yes the peroxide seems to have helped :mrgreen:


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## Captobvious (Mar 11, 2013)

Just want to say a quick thank you for the help figuring everything out up to this point, just wanted to brag for a sec if I could 8) 






dirty, but mostly dried the foils I collected fill the bottom of this coffee pot, any weight estimates would be guesses on my part, others smarter with math than me might be able to figure it out but I'll wait til it's in powder and on a scale, these foils stick to EVERYTHING and don't like to leave where they're at without a fight lol

(perspective)





Here's the leftover stripped fingers, I did notice values still attached to some of them so I'll be sure to give them a real good rinsing and reprocess the ones with values in Caustic and put them back in AP to pull any remainder off in with the next batch. 






I'll be proceeding further after I have a chance to collect some more supplies (after payday) not to mention it's snowing right now but next weekend it should be int he 60's! Finally will be able to get some work done again 

Btw, to whomever suggested this, ty! I picked the only one left on the shelf at my local Wally-world and only $29 so not bad on the wallet either  Can't wait to try it out once I get the remainder of what I need to proceed.






So guys, again, for every thread, for every link, for every argument, THANKS!!!


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