Acid Peroxide

[rewalston]

I depopulated a bunch of boards I had in HCl, removed aluminum and steel the best I could as well as the softer plastics that dissolve in HCl. All of the components were separated, chips awaiting incineration. Everything else went into AP. My solution now is a dark brown, which according to the Copper 2 Chloride document says it's saturated with Copper 1 Chloride and needs more air to turn it back into Copper 2 Chloride. Am I correct in this? I know there is enough HCl present. I have a bubbler going but I'm thinking that it's not powerful enough for the job.

Rusty

 

[Palladium]

Less air = more time.
Give it a few days and check it's progress.
If you take a sample of the ap ( 50 or 100ml ) and add h2o2 to it and it turns a lighter green color then you know that the hcl is good and your problem is air.

 

[rewalston]

Less air = more time.
Give it a few days and check it's progress.
If you take a sample of the ap ( 50 or 100ml ) and add h2o2 to it and it turns a lighter green color then you know that the hcl is good and your problem is air.

I did add some H2O2 to a bit of it and it did indeed turn green, so it's definitely an air problem. I have a bubbler in it as I said but it also has a loose fitting lid on it to keep critters out.

 

[jason_recliner]

the green from adding H2O2 will not last long. And that's ok.

O2 (air) makes it trend green. Copper makes it trend brown. Copper vs air: Copper wins!
Assuming there's enough HCl there to finish the job, it will be brown until the metal is gone, then it will rapidly turn green.

 

[rewalston]

the green from adding H2O2 will not last long. And that's ok.

O2 (air) makes it trend green. Copper makes it trend brown. Copper vs air: Copper wins!
Assuming there's enough HCl there to finish the job, it will be brown until the metal is gone, then it will rapidly turn green.

I'm not exactly sure how much metal is left, there's maybe a gallon of solution give or take. Can't see through it to the bottom.
Rusty

 

[jason_recliner]

Patience, Rusty. It may take weeks.
My first AP was about 2 months with an aquarium pump and no air-stone.

 

[rewalston]

Patience, Rusty. It may take weeks.
My first AP was about 2 months with an aquarium pump and no air-stone.

Thanks Jason, I did check some of the plastic connectors (not affected by acid) and they appear clean. Pulling my strainer bucket out this morning. The solution is actually green but so dark that it looks almost brown. Can't check the stuff in the bottom as they went through my strainer bucket.

Rusty