What is this precipitate?

[resabed01]

The scrap source was fingers from ISA, PCI, memory sticks and some old vintage cards. I had the fingers in AP. I washed the foils with HCL but when I added bleach to dissolve, I get a grey cloudy precipitate.

Here's a picture before HCL/bleach.



It looks more that it actually is, there are bits of card and trash mixed in.

After bleach...




Sure is going to make filtering fun :shock: . Come to think of it I had the same precipitate last time when I cleaned out my sulfuric cell and I used the HCL/bleach for the mud. At he time I assumed it was lead chloride
but I read lead chloride is soluble in boiling water so I heated it up and filtered but the precipitate was unaffected by this, none went through the paper. So then I thought maybe silver chloride but I put the aside and forgot about it.

I didn't expect to see anything else in this batch of fingers except copper. All the finger were trimmed very close and there was very little solder that made it in. If I had to guess, maybe 1/2 gram.
I wouldn't expect to see silver in foils, would I?

Hopefully the filtering won't take all day and I can produce a button tomorrow.

 

[cejohnsonsr]

I get a little bit of that kind of sediment from AP too. Just dirt & copper as far as I can tell. Mine all filters out pretty easy. I use coffee filters the 1st time I filter. Then a charmin plug the 2nd time. Then heat the AuCl & reduce by about 1/2 before I drop with SMB. DON'T BOIL. JUST EVAPORATE. Takes a while but it's worth the effort.

Ed

 

[resabed01]

Well, it formed after I added the bleach to the HCL which lead me to believe it's a metal salt of some kind. It filtered ok and I put the filter paper aside for later.

 

[etack]

Sometimes this happens if your bleach is scented. nothing to worry about just filter it out.

Eric