General PCB processing.

[andu]

Hi there, so i'm in nothing but doubts right here, what would be best way to start processing PCBs? Like motherboards and such from a grade to another, my main plans are on telecom grade, RAM sticks and HDD PCBs from under it.

I had settled for copper chloride for a while but seems it would only work well when it only deals with copper? There is with certainity a lot of variety of metals in there-

I really need to start making a test batch and see the yield because I could potentially get a lot of them.

I want each single bit of metal from the boards like copper or tin not willing to separate the IC's and such but rather do it thru a whole process.

Would a solution of copper chloride work to get rid of all the base metals including copper and maybe silver and leave only gold and plastic behind?

My main plan right now would be get the boards on a recipient and cover with hcl and h2o2, after it get's going I get a bubbler in to not mess with the gold.

Really wondering how i'm separating base metals as I want these pure and if i can take much advantage of the reactivity series table.

I really dislike the idea of pyrolisis as it will surely make a lot of noxious smoke, however, wouldn't it be more effective to just pyrolize the pcb's as a whole ? I know some things can explode upon heating and tin would make a mess at the bottom too.
I remember there was a solution that would remove external layers on PCBs and leave the copper surface visible and clean, that would certainly speed up the process and perhaps even exempt me from using pyrolisis (on the boards i actually want to work with) but I haven't saved the data.

Any advice, recommendation?

 

[Yggdrasil]

Hi there, so i'm in nothing but doubts right here, what would be best way to start processing PCBs? Like motherboards and such from a grade to another, my main plans are on telecom grade, RAM sticks and HDD PCBs from under it.

I had settled for copper chloride for a while but seems it would only work well when it only deals with copper? There is with certainity a lot of variety of metals in there-

I really need to start making a test batch and see the yield because I could potentially get a lot of them.

I want each single bit of metal from the boards like copper or tin not willing to separate the IC's and such but rather do it thru a whole process.

Would a solution of copper chloride work to get rid of all the base metals including copper and maybe silver and leave only gold and plastic behind?

My main plan right now would be get the boards on a recipient and cover with hcl and h2o2, after it get's going I get a bubbler in to not mess with the gold.

Really wondering how i'm separating base metals as I want these pure and if i can take much advantage of the reactivity series table.

I really dislike the idea of pyrolisis as it will surely make a lot of noxious smoke, however, wouldn't it be more effective to just pyrolize the pcb's as a whole ? I know some things can explode upon heating and tin would make a mess at the bottom too.
I remember there was a solution that would remove external layers on PCBs and leave the copper surface visible and clean, that would certainly speed up the process and perhaps even exempt me from using pyrolisis (on the boards i actually want to work with) but I haven't saved the data.

Any advice, recommendation?

PCBs contain nothing but Copper, with some Tin solder.
Some has a bit of Gold plating on parts of the surface.
The values are in the "fingers" and the components.
The big businesses just shreds it and smelts them, then I guess, electrolytic refining of the Copper.
Hydrometallurgical processing make no sense if you plan to do it economically.

 

[andu]

This is what I will be dealing with, this one is attached to a aluminium plate the other one isn't but it has a thick plating on both sides. These come from some 4G devices. Even has some silver plated copper "bells" under all those screws.
If we weren't talked about it being telecom i'd worry more about the tin than the gold.

Mechanical processing isn't really a viable option for me, I can get HCL dirt cheap, even the nitric is fairly cheap but hard to get license unless i get nitrate which is plentiful.

Pretty sure i had shared somewhere picture of the other PCB aswell.

Also, i googled those 2SDP1 things from the board and they stand at 50e each if you buy them new . So there are a few extra goodies i will be saving from there.

 

[Yggdrasil]

View attachment 57055
This is what I will be dealing with, this one is attached to a aluminium plate the other one isn't but it has a thick plating on both sides. These come from some 4G devices. Even has some silver plated copper "bells" under all those screws.
If we weren't talked about it being telecom i'd worry more about the tin than the gold.

Mechanical processing isn't really a viable option for me, I can get HCL dirt cheap, even the nitric is fairly cheap but hard to get license unless i get nitrate which is plentiful.

Pretty sure i had shared somewhere picture of the other PCB aswell.

Also, i googled those 2SDP1 things from the board and they stand at 50e each if you buy them new . So there are a few extra goodies i will be saving from there.

Same history, the big boys shred and smelts before electrolytic refining.
AP or Nitric will give you most of the foils from the boards, even though it may be way less than you think.
It can go straight into AP but needs a few hours in full strength HCl to get rid of the Tin if you go for Nitric.
This will in turn create some issues with small amounts of AR when you swap to Nitric.

Most of the Copper are inside the PCB.

 

[andu]

HCL i can get varies from 21 to like 32% if i'm not wrong, and i mean without doing more than walk few hundred meters and get it. I sorts of feel like skipping much Hydrogen Peroxide and go straight for a bubbler, temperatures are bound to go up here and solution can easily reach 50ºc if I leave it by the sun. Found up to 11% HP but i'm fairly scared of turning gold into solution early of time.

 

[Yggdrasil]

HCL i can get varies from 21 to like 32% if i'm not wrong, and i mean without doing more than walk few hundred meters and get it. I sorts of feel like skipping much Hydrogen Peroxide and go straight for a bubbler, temperatures are bound to go up here and solution can easily reach 50ºc if I leave it by the sun. Found up to 11% HP but i'm fairly scared of turning gold into solution early of time.

Do not use Peroxide for this.
Plain HCl and air bubbling.

 

[Marcel]

Do not expect a significant amount of gold from PCB plating anymore. The days of thick and heavily Gold-plated PCBs are gone. If you want to recover components, use a hot air blower to remove them. I see MLCCs that potentially contain Palladium. The voltage regulators, op-amps, and transistors will contain some Silver. Although modern PCBs may appear nice and precious, they typically only have traces of Gold, usually in the form of flash plating.

 

[andu]

I got this thing going, the plating eventually peels itself off, which is nice, only been going for about 36h.
Seems some copper went into solution then proceeded to cement into magnetite cores, should of removed these forehand but looks nice.
Bubbler doing well but i did cheat and add a bit of peroxide around 12h ago. Must admit the process is pretty slow, only a few of the ICs and MLCCs fall from the boards yet, also, the plating seems pretty thin.

 

[Yggdrasil]

I got this thing going, the plating eventually peels itself off, which is nice, only been going for about 36h.
Seems some copper went into solution then proceeded to cement into magnetite cores, should of removed these forehand but looks nice.
Bubbler doing well but i did cheat and add a bit of peroxide around 12h ago. Must admit the process is pretty slow, only a few of the ICs and MLCCs fall from the boards yet, also, the plating seems pretty thin.

It is not usually used on whole boards.
One reason is that most of the Copper is inside in the traces, besides the Tin and other metals will reduce the effectiveness of the AP leach.
We usually use it solely on fingers and other plated parts of the boards after the Tin and other components are removed.

 

[andu]

Thing is that this board had most the surface flashed in gold, it isn't too thick and not even the one in the picture ( I once had shared a picture of both the boards and its the other one.) but now I know how thick.
Tin removal is a important step for me, I can always process the ICs and MLCCs for rest of the metals in the future.
Silver and palladium won't get dissolved here right?

Edit: Solution is dark now, can barely see thru, this is lacking some heat, rain came since a while and i took sun for granted.

 

[andu]

Alright i'm probably filtering the solution tomorrow, there's still some gold inside the dots but i really wanna see what is up with these foils first. Any idea how i can cement the other metals like copper, tin, alu?

 

[ChopperGreg]

Alright i'm probably filtering the solution tomorrow, there's still some gold inside the dots but i really wanna see what is up with these foils first. Any idea how i can cement the other metals like copper, tin, alu?

Why would you want to cement aluminum?

The value of aluminum is lower than the effort to recover it…and you would need to resort to metals lower on the reactivity table, like magnesium, lithium, sodium and potassium ( all are harder to obtain and will likely cost more than the value of the aluminum ).

I’m not trying to be negative or put anyone down…I’m just trying to understand why. If you are doing it as a chemical experiment, that might be one thing, but as a metal recovery method, you would be losing time and money.

 

[andu]

I once read any liquid can be made drinkable water, surely i don't want to make it drinkable but free of metals or maybe even irrigation wouldn't be a bad thing, I could say it as experiment, yes. A precipitant would do the job but also would lowering the ph gradually and wait for it to simply precipitate?

 

[ChopperGreg]

I once read any liquid can be made drinkable water, surely i don't want to make it drinkable but free of metals or maybe even irrigation wouldn't be a bad thing, I could say it as experiment, yes. A precipitant would do the job but also would lowering the ph gradually and wait for it to simply precipitate?

Below aluminum it gets real hard, and there can be dozens of pathways to deal with a single chemical.

For example, if you have an Aluminum Sulfate solution, you can do a couple of things…none of which is practical from a energy and time standpoint, but helps with learning chemistry.

1) Dehydration of the water, followed by roasting of the salt, to form recoverable Sulfur Trioxide and Aluminum Oxide.

While the Aluminum Oxide is fairly inert, the Sulfur Trioxide can be used to make Sulfuric Acid, but this is a risky pursuit, even with the correct equipment.

2) Application of Potassium Hydroxide to Aluminum Sulfate solution, results in Aluminum Hydroxide which precipitates from a Potassium Sulfate ( Potash of Sulfur ) solution. 6KOH + Al₂(SO₄)3 ➔ 2Al(OH)₃↓ + 3K₂SO₄

The Aluminum Hydroxide can either be roasted to make Aluminum Oxide or used for other things ( like making other Aluminum salts, with the appropriate acid ).


These are just possible examples and I’m not advocating either one, but this is just two pathways for just Aluminum Sulfate, and waste solutions usually have more than one type of salt, which compounds efforts to render relatively safe or useful for other purposes.


Personally, I spend a lot of time with Google Advanced Search, Wikipedia ( learning about the various salts I believe that I will be working with ), and a chemistry app, that lets me test potential chemical reactions.

Can you reduce a solution down to just a potassium salt solution? Sure, but then what do you do with it? It comes down to what you need and what you can do with the skill and equipment you have at your fingertips…personally I can use potash ( and a few other chemicals and potentially Potassium Sulfate ) in some other processes, so that is what I’m working towards, with the way I want to deal with precious metals…but it taken a lot of time and effort to research those pathways, because maybe I don’t need potash or Potassium Sulfate and would rather have Potassium Chloride instead, so I have to change my procedure.

 

[andu]

I sorts of understood you, I'll see how it goes.
.

 

[Sancho_n_Pedro]

Personally, I spend a lot of time with Google Advanced Search, Wikipedia ( learning about the various salts I believe that I will be working with ), and a chemistry app, that lets me test potential chemical reactions.

Hey, whats the chemistry app you use. I was trying to locate one to do the same thing.

 

[andu]

So the waste solution was all cemented down with aluminium i had thrown around. Now, I were thinking if i want to store the aluminium as chloride or hydroxide, what would be the steps to follow? I'm basically left with around 14 liters of liquid, probably slightly acidic in which i tossed about a kilo of aluminium. I read the chloride is pretty unstable so the hydroxide is the way to go?

 

[ChopperGreg]

Hey, whats the chemistry app you use. I was trying to locate one to do the same thing.

One is ‎Chemistry & Periodic Table ( which I use the most @ 80+% of the time ) and the other is ‎CHEMIST by THIX but I don‘t like it as much, with limited number of chemicals. Both are available at the Apple Store, I couldn’t say about Google Play.

There are a couple of others that are somewhat handy, if you are looking to balance your equations and figure out correct amounts, but they are more of a lab or student in college thing because those are for dealing with fairly precise amounts of chemicals.

 

[ChopperGreg]

So the waste solution was all cemented down with aluminium i had thrown around. Now, I were thinking if i want to store the aluminium as chloride or hydroxide, what would be the steps to follow? I'm basically left with around 14 liters of liquid, probably slightly acidic in which i tossed about a kilo of aluminium. I read the chloride is pretty unstable so the hydroxide is the way to go?

Why do you want to store AlCl3? Or Al(OH)3 for that matter?

If you don’t actually have a need for it, you can simply drive off the Cl, by roasting, because AlCl3 decomposes to Al(OH)3, @ 100*C, no need for NaOH or other alkali caustic.

In theory calcining the Al(OH)3, will form fairly inert Al2O3

 

[Proffshuggarn]

Hi Andu
I’ve gone through a similar process like yours before (and even after) I found this great forum and started to follow the advices given by the pro’s here and their knowledge is so valuable for me, cause when I started to do as they suggested, also the results in my beakers started to show results.
I’ve been reading this thread on and on this morning and I have to ask some questions Sir. Hope that’s ok.
In all good intentions, but also for me to learn more
And again, I’m just a beginner here.

I'm basically left with around 14 liters of liquid, probably slightly acidic in which i tossed about a kilo of aluminium. I read the chloride is pretty unstable so the hydroxide is the way to go?

Been there, done that. But why aluminum? Why not start with copper pieces? Or go straight to cement it out on iron and start over? I’m I wrong if I guess that you went up with a big amount of “white-ish” sludge?

Also, i googled those 2SDP1 things from the board and they stand at 50e each if you buy them new

What is 2SDP1? Yes, I did google it also. A “noicefilter”?

Bubbler doing well but i did cheat and add a bit of peroxide around 12h ago.

Why did you add peroxide despite kindly advised from pro’s here that peroxide is not needed, it’ll work anyway?

Well, good that you have a “bubbler”. I use an older aquarium air pump with dual hose connectors, so it airflowing/stirring perfectly and after i started cementing goes much faster, sometimes a little bit too fast I did learned a couple of days ago.
/Dennis