Removing solder from printed circuit boards

[Marcel]

I stand corrected. In that case there is little advantage and HCl seems to be the only realistic approach.

I try to avoid HCl wherever possible in early stages of refining (recovering?) since Silver Chloride is a mess in the procedures lateron (filtering).

 

[Marcel]

Yes but that is easily mitigated by HCl and air.
My post was aimed at the Tin Oxide part of the discussion.

OK, got it!
Tin oxide should easily dissolve in sulphuric acid—the more concentrated and the higher the temperature, the better.
I dissolved it in concentrated sulphuric acid which was heated around 80° quite fast... (Wear protective gear!!!!)

 

[haveagojoe]

Yes but that is easily mitigated by HCl and air.
My post was aimed at the Tin Oxide part of the discussion.

Yes, I don't have a problem dealing with Copper (i) Chloride, only Tin Oxide; and possibly Iron and Nickel oxides, I am still trying to determine if they are part of my black powders. I think it may be an issue for me because my HCl is not concentrated enough.

 

[Yggdrasil]

Yes, I don't have a problem dealing with Copper (i) Chloride, only Tin Oxide; and possibly Iron and Nickel oxides, I am still trying to determine if they are part of my black powders. I think it may be an issue for me because my HCl is not concentrated enough.

If you have the time your HCl can easily be concentrated to 20ish % by evaporation.

 

[haveagojoe]

If you have the time your HCl can easily be concentrated to 20ish % by evaporation.

Yes that will be my next approach I think. For a long time I have been using 10% HCl thinking is fine but in fact it may be the cause of some of my issues it seems.
I will give Sulfuric a try for soldered boards but not hot! Too scary for me!

 

[VolkD]

Have you had problems with this?
I have never encountered any significant filter issues with AP.

If you put things in the AP that have minimal impurities, then there are no problems.

 

[VolkD]

Copper(I) has been a painful filtering experience for me as well sometimes. You should have added more HCl and bubbling is a must.

I agree, hydrochloric acid is certainly cheaper than your time spent resolving such a situation.

 

[VolkD]

I will give Sulfuric a try for soldered boards but not hot! Too scary for me!

Wait, I'll do one test first. If I succeed,...