# stripping base metals and depopulating boards



## rasanders22

I have quiet a few cell phone boards that have to be stripped. Can I just soak them in HCl which would remove all the solder? All he base metals would be dissolved and the surface mounted devices would be removed too.


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## Palladium

When i do boards i take any steel objects off as well as any plastic, mainly white plastic or aluminium on so on. Then i put them in a 5 gallon bucket in your case and sit them in the sun. No air, no stirring, no H2O2 or oxidizer in any way. After about 2-3 days you can take a plastic putty knife and scrap loose what don't fall off. I then take everything that came off the boards, trash and all and run it thru ap. What's left should be a collection of gold foils and some palladium in the bottom with what looks like sand. This is from the Mono cap and maybe some silver chloride in the mix. I then filter the ap thru a Charmin plug in a 2 liter cut off soda bottle. Rinse with water. Leave all the trash in the bottle this is your gold, pd, silver. Then put the cap on the soda bottle. Add hcl and bleach. Immediately swirl and let set maybe 5 minutes. Remove lid and drain. I purposely do this so i make sure i have an excess of oxidizer just in case their may be something in there that is left with base metals, but there shouldn't be. Heat the solution to drive off excess cl and drop with your choice of precipitant. I then add the rest to the stock pot to cement any pd values because they are in small in size and not worth going after with another process. The filter and bottle will hold any silver chloride which can be separated with a ammonium rise to separate it from the trash in the filter.


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## rasanders22

So if I understand you correctly....
1. Strip steel, aluminum, and plastic off the boards. (Already done)
2. Place the boards in Hcl in a sealed bucket for 2-3 days.
3. After 2-3 days manually strip the stuff that doesn't come off.
4. Run all the parts that came off through AP. (Does this include the boards or should I run them seperatly?). Then filter AP through charmin plug.
5. Add AC to dissolve gold and leave pgm's and AgCl.
6. Filter AuCl through charmin plug. 
7. Precipitate Au with smb.
8. The rest is a mix of AgCl and pgm's. Set those aside for a day when I have more.

Should I worry about solids left in the filter?
Should I pull out things like bga's and set those aside with my other chips for a day when I can process those?


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## NoIdea

Afternoon – please excuse my ignorance, but what does leaving your scrap in a sealed bucket out side do to make it easier to remove the bits?

Cheers

Deano


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## butcher

I assumed they were in acid, sealed from animals or what not.


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## Palladium

rasanders22 said:


> So if I understand you correctly....
> 1. Strip steel, aluminum, and plastic off the boards. (Already done)
> 2. Place the boards in Hcl in a sealed bucket for 2-3 days.
> 3. After 2-3 days manually strip the stuff that doesn't come off.
> 4. Run all the parts that came off through AP. (Does this include the boards or should I run them seperatly?). Then filter AP through charmin plug.
> 5. Add AC to dissolve gold and leave pgm's and AgCl.
> 6. Filter AuCl through charmin plug.
> 7. Precipitate Au with smb.
> 8. The rest is a mix of AgCl and pgm's. Set those aside for a day when I have more.
> 
> Should I worry about solids left in the filter?
> Should I pull out things like bga's and set those aside with my other chips for a day when I can process those?



When you do # 5 the pgm's will dissolve also with the gold.
You will recover these after you drop your gold. The way to do this is just to add a piece of copper to the spent solution after you drop your gold. The palladium and if you have platinum in there will cement to the copper. Any silver chloride will be trapped in the filter residues with your trash and chip packages. You can remove the silver chloride with an ammonia rinse and then you can add hcl to the ammonia to re precipitate the silver as a chloride. Then the only thing you are left with is the stripped chips which you can ball mill later. Store them in a gallon zip lock baggy until you have enough to process. Throw the charmin plug in with the used chips.

I then take the stripped boards and run them in some warm sodium hydroxide to remove the green mask and process them in ap also. When your cleaning the parts from step #3 the easiest way i found to do it is take the boards out of the hcl and let them drain for a couple of minutes in a spaghetti strainer. Then i take them and hold them under the water in a 5 gallon bucket with nothing but clean water in it ( about half full ). i take a 1 in putty scraper and holding the board under water i scrap off what didn't come off. Don't worry about any green mask that might come off at this point. Let the stuff settle over night and decant, not filter off the excess water. add everything from the bucket to the ap mix. You will do the same thing with the other 5 gallon bucket with the hcl in it. When i decant the 5 gallon buckets i use a piece of 3/8 in aquarium hose and a pair of hemostats so i can pinch the hose and control the flow. I filter the liquids thru a couple of coffee filter just to make sure i don't loose anything. Don't let the hose touch the bottom of the bucket or you will suck up trash and clog your filter. The filter is only a safety precaution.


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## Palladium

NoIdea said:


> Afternoon – please excuse my ignorance, but what does leaving your scrap in a sealed bucket out side do to make it easier to remove the bits?
> 
> Cheers
> 
> Deano




It removes the solder, tin, lead and other base metals, but not the copper because their is no oxidizer. Hcl alone will not dissolve copper. That’s why we use H2O2 or air to oxidizer copper to copper oxide which hcl will dissolve. If you leave it longer than 2-3 days the heat and oxidizer from the air will start to attack your copper. You don't want this yet. It will also make the green mask come off which you don't want yet if you leave it longer. If you do it right and keep the oxidizer out of the equation you will be surprised at how many boards you can run through the hcl to remove the solder. When you get air in there it just screws it all up. This is a three step recovery process. Not refining.


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## Palladium

butcher said:


> I assumed they were in acid, sealed from animals or what not.



I have cats and cats are curious.  

It sort of goes unspoken, but yeah you need a lid on there to stop fresh air from entering the solution once the hcl absorbs what is trapped in the bucket when you first seal it up. I said don't stir earlier. What i meant was with the lid off and exposed to air. With the lid on and sealed you can give it a swirl every now and then to help dislodge the components from the board. It's all about the air.


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## naboobo2000

After searching and searching I cam upon this thread. OH I LOVE YOU ALL!

Let me say it proud, I am a big time newb. I am an avid prospector but am starting to look at these things called cell phones. I have well over a 300 boards and have access to 1000's. If I follow the above steps first with the parts that came off in the HCL, then with the boards all using AP, I should have success?

I do not know what a charmin plug is? Or what it does? How does this filtering differ then Steve's video?

Thanks a-lot and WoW what a great site with good people helping each other.

Chris


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## philddreamer

A charmin plug is a piece of toilet paper, used as a filter. You insert it in a funnel, similar to the one in the pic. (in the pic. I used a piece of fiber glass insulation).

Phil


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## kjavanb123

I also have access to a 600lb a month lot of mixed PC cards, memory cards, IDE cards, and etc, also 5 tons of motherboards, please kindly if this method can be used to strip the boards at once. then process them later.

Regards,
Kevin


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## Geo

kjavanb123 said:


> I also have access to a 600lb a month lot of mixed PC cards, memory cards, IDE cards, and etc, also 5 tons of motherboards, please kindly if this method can be used to strip the boards at once. then process them later.
> 
> Regards,
> Kevin



some of the PVC sockets on motherboards are soluble in hcl in will dissolve.this dissolved plastic does not go into solution but rather turns into a gooey mess. some sockets will hold up to the acid and others will fail. it will cover components and theres no good way to remove it after it gets in this state.


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## joem

You have access to all this and you want to throw it into a pot? Cherry pick the best and make cash with the rest. That much could be a full time monthly income per month for most.


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## skippy

kjavanb123 said:


> I also have access to a 600lb a month lot of mixed PC cards, memory cards, IDE cards, and etc, also 5 tons of motherboards, please kindly if this method can be used to strip the boards at once. then process them later.
> 
> Regards,
> Kevin



I think if you want to use this method on multi ton quanitities of boards, you are basically on your own, because no one here has done that, and there are likely good reasons for that. I think you'll be in for lots of surprises along the way if you can get it to work at all. I hope that your venture is working out for you, truely i do, but maybe you could have figured out what to do with the boards before you bought the industrial building :shock:


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## kjavanb123

All,

This is a clearifcation on this matter, first of all, I did not buy this facility, I basically rented this unit from the local government that they set it up and lend to a school grad to work on it and recycle and refine metals from e waste. They couldnt handle it, only produced few grams of copper and tin, state paid for everything, shredder, an electrowinning unit, crane, a CRT recycling unit, and many more, since a year ago the facility had been abandoned due to lack of knowledge, until I showed them my gold silver recovered from CPUs and won the auction, they litterly gave me 18 MT of mixed e waste for free and asked to just run the place, so far I cleaned up the mix wastes, and once I could produce I will be giving an stream of e waste government collects on national scale which is 30 tons a month just computer motherboards alone, along maybe a ton or more of mixed cards, and other electronic junks.
That is why I travled to Singapore to meet up with this consultant who has been with the only recycling and refining company there to give me some guides on how to run things on commercial scales. He suggested to use air chisel and cheap labor locally to basically cherry pick the gold plated and gold items, then process them separately.
I didnt feel like he knows as much as some of the members here, so I even asked the forum for a consultant to provide some support and even be open to some sort of joint venture, where he can help me with processing while I can get my hands on a large volume of e waste.
The only trick about the facility here is I can not just sell the boards to outside, all e waste has to be recycled and refined here locally, the stripped boards, dteel, plastics and etc can be sold outside though.
Here is the picture of plant before and after some clean up,



And this is a week later, it is much cleaner right now, also found another 20 lbs of mixed cards today,



One thing that really gets me going is the fact, the volume of materials we can get, also the price we pay for that volume is very cheap, but the catch is we have to refine in house, so again if any of you pros are interested in this please contact me in PM to go over details.

Regards,
Kevin


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## solar_plasma

Nnnnnnice playground! :lol:


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## rickbb

Looks like a lot of work, with a big reward in the end. I'd like to happen on a deal like that, be my retirement job.


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## skippy

Ok, I get it better now, sorry if I was dismissive, or disrespectful. I would consider talking with the people who are setting the conditions and seeing if you could be allowed to export the boards whole with the condition that a great part of the profit be put towards more equipment and practice on treating the materials. Its a nice idea for keeping workers employed, the in house recovery and concentration, but it's likely a ways off till you have everything ironed out and it doesn't really seem like a totally fair expectation on their part, but maybe it's not something that can be argued. 

It's a unique and interesting experience for you, and it will be a big feather in your cap to get it working!


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## skippy

Do they expect you to process the low grade boards?


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## kjavanb123

It is an option provided by them to process low grade boards, or export them. However, I think there are some low and mid yield ICs on those low grade boards that once the volume is large it can add up, so I have cherry picked them as much as we can.
Our main focus would be computer motherboards, fingers, cards and copper wires. 

Your assistance snd consulting won't be under estimated.

Thanks
Kevin


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## rewalston

Palladium said:


> rasanders22 said:
> 
> 
> 
> So if I understand you correctly....
> 1. Strip steel, aluminum, and plastic off the boards. (Already done)
> 2. Place the boards in Hcl in a sealed bucket for 2-3 days.
> 3. After 2-3 days manually strip the stuff that doesn't come off.
> 4. Run all the parts that came off through AP. (Does this include the boards or should I run them seperatly?). Then filter AP through charmin plug.
> 5. Add AC to dissolve gold and leave pgm's and AgCl.
> 6. Filter AuCl through charmin plug.
> 7. Precipitate Au with smb.
> 8. The rest is a mix of AgCl and pgm's. Set those aside for a day when I have more.
> 
> Should I worry about solids left in the filter?
> Should I pull out things like bga's and set those aside with my other chips for a day when I can process those?
> 
> 
> 
> 
> When you do # 5 the pgm's will dissolve also with the gold.
> You will recover these after you drop your gold. The way to do this is just to add a piece of copper to the spent solution after you drop your gold. The palladium and if you have platinum in there will cement to the copper. Any silver chloride will be trapped in the filter residues with your trash and chip packages. You can remove the silver chloride with an ammonia rinse and then you can add hcl to the ammonia to re precipitate the silver as a chloride. Then the only thing you are left with is the stripped chips which you can ball mill later. Store them in a gallon zip lock baggy until you have enough to process. Throw the charmin plug in with the used chips.
> 
> I then take the stripped boards and run them in some warm sodium hydroxide to remove the green mask and process them in ap also. When your cleaning the parts from step #3 the easiest way i found to do it is take the boards out of the hcl and let them drain for a couple of minutes in a spaghetti strainer. Then i take them and hold them under the water in a 5 gallon bucket with nothing but clean water in it ( about half full ). i take a 1 in putty scraper and holding the board under water i scrap off what didn't come off. Don't worry about any green mask that might come off at this point. Let the stuff settle over night and decant, not filter off the excess water. add everything from the bucket to the ap mix. You will do the same thing with the other 5 gallon bucket with the hcl in it. When i decant the 5 gallon buckets i use a piece of 3/8 in aquarium hose and a pair of hemostats so i can pinch the hose and control the flow. I filter the liquids thru a couple of coffee filter just to make sure i don't loose anything. Don't let the hose touch the bottom of the bucket or you will suck up trash and clog your filter. The filter is only a safety precaution.
Click to expand...


Sounds like a good way to collect silver as a chloride if you don't have nitrates to work with. 
Rusty


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## rewalston

A quick question about the HCl originally used to depopulate the boards. Once it's reached it's usefulness, does it go to the stockpot or the waste pot? I know you don't want to use it for AP.

Rusty


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## kernels

Straight to the waste, very unlikely to be any PMs in solution as you have basically made a large quantity of Stannous Chloride.


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## rewalston

kernels said:


> Straight to the waste, very unlikely to be any PMs in solution as you have basically made a large quantity of Stannous Chloride.


That's what I thought but I figured I'd better check first. Don't need to be tossing anything that might have something else in it.

Rusty


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## rewalston

What would be a suitable container to collect and accumulate AgCl?

Rusty


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## Grelko

rewalston said:


> What would be a suitable container to collect and accumulate AgCl?
> 
> Rusty



I'm not sure of certain types of plastic, others can help with this. A glass jar or crock should be ok.


Hoke's page 49 (Page 48 bottom, saving the silver) She says to leave it in the "crock", and another part says about having it in the dark.



FrugalRefiner said:


> Grelko said:
> 
> 
> 
> 
> 
> 
> How would drying out the silver chloride, complicate treatment later on?
> 
> 
> 
> If you let it dry, it forms a very strong crystalline matrix that will make further processing more difficult.
> 
> Click to expand...
Click to expand...

 http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=23226&start=30 Page 2, Frugal was giving me tips about my button.


Use a dark colored bottle, so that the AgCl doesn't break down into elemental silver and Cl gas. https://socratic.org/questions/why-do-we-store-silver-chloride-in-dark-coloured-bottle

On a side note  , if you keep it wet, don't keep it in a mason jar, in sunlight. It will slowly eat through the metal lid.


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## 4metals

I always prefer a good 5 gallon bucket with a secure lid. This is placed under a bench or shelf away from direct bright light and it should suffice.

The reason I prefer the 5 gallon bucket is I have a spreadsheet that I developed to determine the quantity of 50% caustic and Karo syrup to add based on the depth of the silver chlorides in a 5 gallon bucket, so when the bucket starts filling up, stick in a plastic ruler and put the depth in inches into the spreadsheet and it tells you how much of each to use.


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## rewalston

4metals said:


> I always prefer a good 5 gallon bucket with a secure lid. This is placed under a bench or shelf away from direct bright light and it should suffice.
> 
> The reason I prefer the 5 gallon bucket is I have a spreadsheet that I developed to determine the quantity of 50% caustic and Karo syrup to add based on the depth of the silver chlorides in a 5 gallon bucket, so when the bucket starts filling up, stick in a plastic ruler and put the depth in inches into the spreadsheet and it tells you how much of each to use.



A 5 gal bucket sounds like a good option, it will take a long time for me to collect enough AgCl to fill the bucket. I don't know if we have Karo here in Ontario, but we do have Golden Syrup which I believe is basically the same thing. I'll have to pick up another bucket to dedicate to that. I have 4 of them, but they are for different things in reclaiming and waste treatment. Thank you.
Rusty


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## 4metals

Any corn syrup will do the trick. When you are ready let me know and I'll post the spreadsheet to make it easier for you.


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## rewalston

4metals said:


> Any corn syrup will do the trick. When you are ready let me know and I'll post the spreadsheet to make it easier for you.


Thanks 4metals, I'll do that. Right now I'm just getting ready to depopulate some boards. I have to wait to get some more NaOH to remove the solder mask on a few of the boards before I start doing any recovery.
Rusty


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## Grelko

rasanders22 said:


> So if I understand you correctly....
> 1. Strip steel, aluminum, and plastic off the boards. (Already done)
> 2. Place the boards in Hcl in a sealed bucket for 2-3 days.
> 3. After 2-3 days manually strip the stuff that doesn't come off.
> 4. Run all the parts that came off through AP. (Does this include the boards or should I run them seperatly?). Then filter AP through charmin plug.
> 5. Add AC to dissolve gold and leave pgm's and AgCl.
> 6. Filter AuCl through charmin plug.
> 7. Precipitate Au with smb.
> 8. The rest is a mix of AgCl and pgm's. Set those aside for a day when I have more.
> 
> Should I worry about solids left in the filter?
> Should I pull out things like bga's and set those aside with my other chips for a day when I can process those?




Since I used a hammer and chisel to depopulate my boards, I can just skip to number 4 and proceed from there. I'm taking out the plastic "pin holders etc", steel and aluminum at the moment. The boards will be done at another time.

Edit - Switched question mark to a period. It wasn't supposed to be in the form of a question.


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## upcyclist

4metals said:


> I always prefer a good 5 gallon bucket with a secure lid. This is placed under a bench or shelf away from direct bright light and it should suffice.
> 
> The reason I prefer the 5 gallon bucket is I have a spreadsheet that I developed to determine the quantity of 50% caustic and Karo syrup to add based on the depth of the silver chlorides in a 5 gallon bucket, so when the bucket starts filling up, stick in a plastic ruler and put the depth in inches into the spreadsheet and it tells you how much of each to use.


Genius!

I use a quart mason jar for mine--with a plastic lid. You can buy a box of 12 plastic mason jar lids for a few bucks at walmart in the canning section. I love 'em--they're great for storing, but of course are horrible reaction and heating vessels. I also use 'em to store some dry chems, like copperas, that tend to show up in cheap ziplock bags.


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## worldavi

Palladium said:


> When i do boards i take any steel objects off as well as any plastic, mainly white plastic or aluminium on so on. Then i put them in a 5 gallon bucket in your case and sit them in the sun. No air, no stirring, no H2O2 or oxidizer in any way. After about 2-3 days you can take a plastic putty knife and scrap loose what don't fall off. I then take everything that came off the boards, trash and all and run it thru ap. What's left should be a collection of gold foils and some palladium in the bottom with what looks like sand. This is from the Mono cap and maybe some silver chloride in the mix. I then filter the ap thru a Charmin plug in a 2 liter cut off soda bottle. Rinse with water. Leave all the trash in the bottle this is your gold, pd, silver. Then put the cap on the soda bottle. Add hcl and bleach. Immediately swirl and let set maybe 5 minutes. Remove lid and drain. I purposely do this so i make sure i have an excess of oxidizer just in case their may be something in there that is left with base metals, but there shouldn't be. Heat the solution to drive off excess cl and drop with your choice of precipitant. I then add the rest to the stock pot to cement any pd values because they are in small in size and not worth going after with another process. The filter and bottle will hold any silver chloride which can be separated with a ammonium rise to separate it from the trash in the filter.


I dont get this.....You are saying that the resistors and IC chips on the board just fall of after a few days in the sun??. Remember, this topic is "depopulating" boards. what about the circuit traces that are plated gold?


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## Palladium

hcl + sun. The gold traces that are left on the board can be run in ap to recover any gold foils or you can use ar to dissolve the traces that are left. It's all according to the materials or the results you are trying to achieve.


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## rewalston

Palladium said:


> hcl + sun. The gold traces that are left on the board can be run in ap to recover any gold foils or you can use ar to dissolve the traces that are left. It's all according to the materials or the results you are trying to achieve.


What if there is water in the equation? With so much tin in solution if it accidentally dissolved some gold because of the water how would you get it back?
Rusty


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## Grelko

rewalston said:


> ]
> What if there is water in the equation? With so much tin in solution if it accidentally dissolved some gold because of the water how would you get it back?
> Rusty



--------------------------------------------------------------------------------------
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=13250 This link deals with silver+ tin, but it's still about metastannic.


dtectr said:


> According to an older text I found in google books Incineration to red heat converts the metastannic acid (insoluble in all acids and bases) to tin oxide, soluble in concentrated HCl and H2SO4.



Edit - From reading about metastannic acid over the last hour or so, it seems easiest to just incinerate to red heat, then redissolve in HCl.

Edit again - If it's in AP, just saturate the solution with something higher in reactivity than gold (ex. copper), it'll push the gold out.

Page 699-700 
"Metastannic acid is freely soluble in potassic and sodic hydrates, as well as in solutions of their carbonates..."
https://books.google.com/books?id=rIgMAQAAIAAJ&pg=PA699&lpg=PA699&dq=metastannic+solubility&source=bl&ots=B6ZLqte0FT&sig=OFcHsBtAafHk-kNr82pXIJ6Jsx8&hl=en&sa=X&ved=0ahUKEwjjvLGS1Y3OAhWEeSYKHdfDBIAQ6AEIRzAG#v=onepage&q=metastannic%20solubility&f=false

MSDS, soluble in excessive sodium hydroxide
http://www.showakako.co.jp/po/assets/files/SDS-20160708/Inorganic%20Chemicals/SDS-G1016E%20Metastannic%20acid%20EN.pdf


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## upcyclist

rewalston said:


> What if there is water in the equation? With so much tin in solution if it accidentally dissolved some gold because of the water how would you get it back?



Stannous chloride turns AgCl into colloidal gold, right? So it shouldn't make it past the Charmin plug, right?

Also, even if the chlorine in your tap water is somehow enough of an oxidant to dissolve some gold, it also has to get past every other metal in the reactivity table above gold. Since we're talking about depopulating boards here, I wouldn't think that very likely.

Sent from my GT-N8013 using Tapatalk


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## Topher_osAUrus

upcyclist said:


> rewalston said:
> 
> 
> 
> What if there is water in the equation? With so much tin in solution if it accidentally dissolved some gold because of the water how would you get it back?
> 
> 
> 
> 
> Stannous chloride turns AgCl into colloidal gold, right? So it shouldn't make it past the Charmin plug, right?
> 
> Also, even if the chlorine in your tap water is somehow enough of an oxidant to dissolve some gold, it also has to get past every other metal in the reactivity table above gold. Since we're talking about depopulating boards here, I wouldn't think that very likely.
> 
> Sent from my GT-N8013 using Tapatalk
Click to expand...


It doesnt turn silver chloride (AgCl) into colloidal gold, but for auric chloride it does


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## rewalston

I have been using my crockpot to depopulate the boards I have. I ran out of HCl so I added water approx 50/50. No head room to speak of in the crockpot. I heated it up for about 4 hours and then shut it off and let it set overnight to work it's magic. I have to redo some of the boards as all the solder hasn't been removed. I can see a lot of tiny needles (metallic) in the solution and a lot of blackish powder in the solution. I'm assuming that the needles I'm seeing could be tin, but I'm not sure. It does appear that some of the gold was removed from some finger boards that were in there. I still have about 1/4 of the boards to redo, not heating this time, I'll just let it set for another day or two, also some BGA chips that the solder hasn't come all the way off yet. When it's all done I'll filter out the components and boards and then run it through a charmon plug to collect the powders. Not sure with tin in solution to see if there's any gold as well. I don't know yet if there is any silver in there yet or not, don't see any white precip.


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## upcyclist

Topher_osAUrus said:


> upcyclist said:
> 
> 
> 
> 
> 
> rewalston said:
> 
> 
> 
> What if there is water in the equation? With so much tin in solution if it accidentally dissolved some gold because of the water how would you get it back?
> 
> 
> 
> 
> Stannous chloride turns AgCl into colloidal gold, right? So it shouldn't make it past the Charmin plug, right?
> 
> Also, even if the chlorine in your tap water is somehow enough of an oxidant to dissolve some gold, it also has to get past every other metal in the reactivity table above gold. Since we're talking about depopulating boards here, I wouldn't think that very likely.
> 
> Sent from my GT-N8013 using Tapatalk
> 
> Click to expand...
> 
> 
> It doesnt turn silver chloride (AgCl) into colloidal gold, but for auric chloride it does
Click to expand...

Crap, sorry. Autocorrect nailed me and I didn't catch it. I meant (and originally typed) AuCl. 

Sent from my GT-N8013 using Tapatalk


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## Topher_osAUrus

I figured it was just a small typo, we all have them (i have them alot)

The long thin needles that have came out of solution while cooling are most likely lead chloride (long thin needles, actually quite pretty to look at) 
If it were me, i would remove the boards/solids from the solution, let it cool, dropping the PbCl needles and any other slightly solubles, then filter the acid off from them, and return the acid to the pot with the boards to keep working.


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## rewalston

Topher_osAUrus said:


> I figured it was just a small typo, we all have them (i have them alot)
> 
> The long thin needles that have came out of solution while cooling are most likely lead chloride (long thin needles, actually quite pretty to look at)
> If it were me, i would remove the boards/solids from the solution, let it cool, dropping the PbCl needles and any other slightly solubles, then filter the acid off from them, and return the acid to the pot with the boards to keep working.


Tophur, the needles are long and thin, they are more like metallic whiskers. PbCl needs are generally (from what I've seen) long and almost white in appearance.

Rusty


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## Topher_osAUrus

Now you have me curious what yours look like, when you said long and thin, i thought you meant the "whisker needles". Do you have a picture you could upload?


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## rewalston

Topher_osAUrus said:


> Now you have me curious what yours look like, when you said long and thin, i thought you meant the "whisker needles". Do you have a picture you could upload?


This first picture is the first bucket I used with HCl/H2O no heat.


This picture shows the bucket with just water for rinsing the parts in after I scraped off the parts. The parts and the boards are in the bucket for now.


This is one of the boards that are still working in the crockpot, no heat added this time. You can make out the little metallic whiskers. Notice also that it appears that the gold has been removed from the fingers.


The whole thing is rather confusing. I know that I should have used straight HCl, but I ran out and thought that adding water to it wouldn't complicate things. I won't have any more acid until end of the month.

Rusty


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## g_axelsson

Easy!

The water is actually an electrolyte, a lot of metal salts and acid traces. So the board, containing a lot of different metals in electrical contact with each other creates small "batteries" where a current runs through the circuit and more noble metals are plated out and less noble goes into solution. With tin in solution your needle like metallic crystals is probably tin, it often creates a fluffy mass of thin crystals.

This is an example of electrolysis of tin chloride.
https://www.youtube.com/watch?v=G1sq4hnrBgM

Your gold hasn't been removed, it is just covered in a thin layer of metallic tin, try wash it with HCl.

Göran


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## rewalston

g_axelsson said:


> Easy!
> 
> The water is actually an electrolyte, a lot of metal salts and acid traces. So the board, containing a lot of different metals in electrical contact with each other creates small "batteries" where a current runs through the circuit and more noble metals are plated out and less noble goes into solution. With tin in solution your needle like metallic crystals is probably tin, it often creates a fluffy mass of thin crystals.
> 
> This is an example of electrolysis of tin chloride.
> https://www.youtube.com/watch?v=G1sq4hnrBgM
> 
> Your gold hasn't been removed, it is just covered in a thin layer of metallic tin, try wash it with HCl.
> 
> Göran


Thank you Göran, I had a feeling it was tin. I'll finish depopulating what I have. And put all the boards, etc in my bucket of water and at the end of the month, I'll get some more HCl and do a wash of everything before I do anything else.
Rusty


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## kernels

Certainly looks like Tin crystals


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## Grelko

Since you should take out the plastic (already spent the last few days pulling pins from holders), what about the older dipped capacitors, ceramic or glass resistors/diodes, or other Items like fuses that are encased in a rectangle ceramic shell, glass screens from old VCRs, stereos and other bits of trash? I'm trying to sort my pile of components a bit before processing.

So far I've removed alot of the copper windings, aluminum caps, iron and plastic.

I'm thinking for certain pieces, I'll need to incinerate or pyrolize, then crush and reprocess.

I won't be using nitric for this.


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## rewalston

Ok, I finally got my goofed up solutions filtered. And the parts are ready to go into pure HCl to correctly remove the tin. The filters I have I'm assuming that I can, after the boards, etc have desoldered, put into the HCl to remove the tin that was caught in the filters along with everything else. Just for safety sake I checked my solution with SnCl to make sure there was no gold dissolved. I'm safe . That HCl/H2O solution is now been placed into my waste bucket to neutralize. I also was wonder the water that I rinse everything off into, after everything is filtered out of it, that goes to waste as well correct? Because there would be some HCl in it from rinsing off parts.

Rusty

edit: The filters that I have currently from my screw-up has a lot of black sediment.


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## g_axelsson

That black sludge from depopulating components could contain metallic gold. Easily tested by dissolving a small sample in AR and tested with stannous.

The main source of metallic gold in the black sludge would be from gold dissolved in the solder. Boards using ENIG on solder pads or gold plated component legs will have the gold dissolved by the molten tin. This is released when the solder is dissolved.

Even on boards without ENIG or gold plated legs there could be a bit of gold in the solder, transferred from other boards in the wave solder machine. For pure surface mounted boards there is no cross contamination between boards, but for boards with through hole mounted components there is a distinct possibility.
Gold in solder baths is a problem for some manufacturers, whenever the gold content reaches close to 0.5% the solder bath has to be replaced. Too much gold creates fragile solder connections that easily crack over time.

Göran


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## rewalston

g_axelsson said:


> That black sludge from depopulating components could contain metallic gold. Easily tested by dissolving a small sample in AR and tested with stannous.
> 
> 
> Göran


That is what I suspect. I'm going to be using A/P on everything once the remainder of the tin/solder is removed. Once the A/P recovery is done, the refining will be with HCl/bleach.

Rusty


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## Grelko

I had a bit of trouble with processing "because of my old A/P solution", after manually stripping off components. 

I'm just double checking that everything is working properly now.

I had left over AP (possibly just CuCl2 since it was a nice emerald green) from when I first started processing material. I had previously "partially" neutralized it, so the PH was around 2-2.5. 

I put a few pounds of components into the bucket with the old AP and turned the bubbler on. When I checked it later, I noticed that it had foamed up a bit, so I took a spray bottle and knocked the foam down. The next day, I had to knock the foam down again (the foam looked dark orange).

Today, I put in 1/2 gallon of HCl and mixed it up, so the PH should be around 1-1.5, but I haven't checked it yet. The green is completely gone and now the color is grey (so far, there's no more foam). It seems to be working fine now. The grey color "getting more clear", should be any tin or zinc from plated wire/legs or solder. 

I was going to let it run for another week or two, then collect any left over pieces and powder.

I'll be checking the solution with stannous periodically, and possibly post a few pictures, if I have any problem figuring out certain "mixed" stannous colors. There may be some Pt or Pd in solution at some point because of the MLCCs.

Everything that is collected "any plastic, powder, chips etc" along with a good bit of un-dissolved copper, will be rinsed with clean water into a bucket, to remove any powder that may be trapped within some pieces.

Afterwards, any plastic will be removed to be incinerated later on, just incase there's any trapped powder left, while the rest of the undissolved material/powder is put into fresh AP to continue processing.

Once the rest has been dissolved, I'll be saturating the solution with copper to make sure any PMs are dropped, then collect all of the black and grey powder for further processing.

Edit - Seeing that at the end of processing this, my old AP should be mainly "if not completely" zinc chloride, from brass etc. Would I still need to use iron in the disposal? I'll probably put in a chunk anyways to be on the safe side.

Edit - spelling


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## rewalston

When I placed the boards that I have into NaOH solution to remove the mask, I noticed that some gold came off with the mask. I plan on filtering the solution, but before dissolving the gold should I incinerate first as this is an alkaline solution I'm dealing with. Or would just rinsing well with water be ok.

Rusty


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## anachronism

Rinsing with water and washing it well will be perfectly fine. Some advocate incineration for everything however opinions do differ.


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## rewalston

anachronism said:


> Rinsing with water and washing it well will be perfectly fine. Some advocate incineration for everything however opinions do differ.


Thank you, I was looking over some other posts that I have bookmarked and it appears that just a good washing should do it.

Rusty


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## rewalston

Well, starting to clean up my waste buckets before dissolving PMs. I started with the easiest one, my 2 gallons of rinse water that I washed all of the stripped boards in. Tested it with a PH strip and it's definitely acidic. I took the NaOH solution (approx. 1/2 gal) that I used to strip the boards with (after filtering solids out of it) and poured it into my rinse bucket. Definitely some metals dissolved in the rinse water, the solution immediately started to cause metals to come out of solution. I stirred it up really well so that everything was mixed well. The solution took on a bright navy blue color, thought it was pretty cool. I'll let it sit for a few days so that the precipitant settles out and then I'll filter it. Now my next question, the PH right now is above 9. My test strips were to test pools with so my range of PH is only 6.2 - 9. To bring the PH back down to 7ish, how should I go about that, add HCl or H2SO4 until it's in the 7 range?

Rusty


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## anachronism

If you're happy that the metal is out, then sure use HCl to bring it back down to pH7.


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## Barren Realms 007

rewalston said:


> Well, starting to clean up my waste buckets before dissolving PMs. I started with the easiest one, my 2 gallons of rinse water that I washed all of the stripped boards in. Tested it with a PH strip and it's definitely acidic. I took the NaOH solution (approx. 1/2 gal) that I used to strip the boards with (after filtering solids out of it) and poured it into my rinse bucket. Definitely some metals dissolved in the rinse water, the solution immediately started to cause metals to come out of solution. I stirred it up really well so that everything was mixed well. The solution took on a bright navy blue color, thought it was pretty cool. I'll let it sit for a few days so that the precipitant settles out and then I'll filter it. Now my next question, the PH right now is above 9. My test strips were to test pools with so my range of PH is only 6.2 - 9. To bring the PH back down to 7ish, how should I go about that, add HCl or H2SO4 until it's in the 7 range?
> 
> Rusty



I know you are trying to do what you can with what you have at hand but you need to stop using the test strips for pools they are not even useful when working with the chemicals we work with. You can find some really inexpensive PH meters on Ebay that would do you a better job.


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## rewalston

Thanks Barrens, those are on my buy list. But it still didn't answer my question.


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## anachronism

rewalston said:


> Thanks Barrens, those are on my buy list. But it still didn't answer my question.



That's ok Rusty. I already answered it two posts up.


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## Barren Realms 007

rewalston said:


> Thanks Barrens, those are on my buy list. But it still didn't answer my question.



Add some HCl to it to adjust your PH down.


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## rewalston

anachronism said:


> rewalston said:
> 
> 
> 
> Thanks Barrens, those are on my buy list. But it still didn't answer my question.
> 
> 
> 
> 
> That's ok Rusty. I already answered it two posts up.
Click to expand...

Thank you anachronism. I know that I need something better to test with. Need a lot of things, just a tight budget on low income. Takes time.


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## anachronism

Rusty if you can read the pH 7 then you're good as you are for now. Enjoy.


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## rewalston

anachronism said:


> Rusty if you can read the pH 7 then you're good as you are for now. Enjoy.


Thanks, I did some reading on the Dealing with Waste thread and 4Metals I think it was, said that the ph only needs to go to 2.5 after adding iron to the pot to drop copper and then raise the PH. So I guess I kind of over did it with my rinse water, cleaning it up. Still need to get something better than what I have but they will work for now.

Rusty


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## g_axelsson

A 100 or 200 pack of pH strips from China costs a dollar on ebay... including shipping. Haven't checked prices since two years ago when I bought a batch.

Göran


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## upcyclist

Aye--I have a pH meter, but generally don't use it too much in my waste stream. The strips (or tape) are handy for qualitative stuff. I use the meter when I need quantitative.

--Eric


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## Grelko

Palladium said:


> rasanders22 said:
> 
> 
> 
> I then take the stripped boards and run them in some warm sodium hydroxide to remove the green mask and process them in ap also.
Click to expand...


After the green mask and copper/traces have been removed, is the board itself just fiber glass? Could I rinse it off with water and toss it in with my regular trash, since there isn't anything left but the board?


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## Grelko

Grelko said:


> Palladium said:
> 
> 
> 
> 
> 
> rasanders22 said:
> 
> 
> 
> I then take the stripped boards and run them in some warm sodium hydroxide to remove the green mask and process them in ap also.
> 
> 
> 
> 
> 
> Click to expand...
> 
> 
> After the green mask and copper/traces have been removed, is the board itself just fiber glass? Could I rinse it off with water and toss it in with my regular trash, since there isn't anything left but the board?
Click to expand...


Problem solved, it's just fiberglass. It can be recycled. 

You should probably keep it separate from other recyclables and make sure it has been washed off very well, so that you don't contaminate other materials with chemical residues from refining.


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