HCl+H2O2 on CPUs

[Renaldas]

Tryied HCl+H2O2 on CPU to see what will happen, HCl standard, about 30 percent, H2O2 very strong, 35 percent. It works on CPU, but I dont understand one thing, where have some of my gold dissapeared? After using this mixture I noticed the pins of CPU are almost black, they partly dissolve, but I noticed almost no gold foil from pins. Usually, i separate them in diluted nitric acid, after some time pins loosen, and I can see gold foil floating in solution. This time there is no gold foil and almost no pins.
Tested the solution with SnCl2, there is no gold in solution, tryied to presipitate with SMB, there is no precipitate. So, there have my gold dissapeared?

 

[qst42know]

Your gold is likely the black stuff cemented to the remaining base metals.

Gold doesn't want to stay in solution when base metals are available.

 

[Lino1406]

Maybe the concentration of H2O2 is too high,
causing Cl2 formation. What exactly you see
when adding SnCl2? (Put a bit more)

 

[patnor1011]

how many cpus are you processing? when i did them i put about 30-40 of them in bucket. they got black coating almost immediately. i left them sit there couple of days. after that i had only fiber bases and nice hollow pipe like foils... no sign of black residue.

 

[glorycloud]

So, are you trying to tell me that in order to be successful when
processing e-scrap prior to refining it you have to be PATIENT
and allow the acids time to do their job?? :shock:

Now there is a lesson that every noobie could very well embrace!
Perhaps it needs to in the top 10 of the "welcome in" page. 8)

 

[Renaldas]

Your gold is likely the black stuff cemented to the remaining base metals.

Gold doesn't want to stay in solution when base metals are available.

Yes, you are right, I forgot that.

 

[Renaldas]

Maybe the concentration of H2O2 is too high,
causing Cl2 formation. What exactly you see
when adding SnCl2? (Put a bit more)

What concentration of hydrogen peroxide is the best? After I add this 35% hydrogen peroxide, there is very violent reaction with bubbling, solution gets warm and even hot, and there is very significant smell of chlorine.
SnCl2 shows nothing.

 

[Renaldas]

how many cpus are you processing? when i did them i put about 30-40 of them in bucket. they got black coating almost immediately. i left them sit there couple of days. after that i had only fiber bases and nice hollow pipe like foils... no sign of black residue.

I processed about 10-20 CPUs. After several days and adding of H2O2 in small increments at lower concentration several times, it seems, like gold pins, fingers and foil is falling down. Maybe the concentration of H2O2 is too high, and this dissolve some gold, it immediatly precipitate on base metals, and this mimic black pins.

 

[Barren Realms 007]

Maybe the concentration of H2O2 is too high,
causing Cl2 formation. What exactly you see
when adding SnCl2? (Put a bit more)

What concentration of hydrogen peroxide is the best? After I add this 35% hydrogen peroxide, there is very violent reaction with bubbling, solution gets warm and even hot, and there is very significant smell of chlorine.
SnCl2 shows nothing.

Suggestion would be for you to use 3% peroxide till you are familiar with your process.

 

[Lino1406]

Smell of chorine suggests too
much H2O2, what will oxidize
SnCl2 before Au+3 (if any) oxidizes it