Battery Acid 36% for acid cell

[nickjam]

I have been searching for quite a while for an answer to this question. Can I use 36% battery acid for an acid cell to remove Gold from gold plated computer pins?

Using a lead cathode
Copper anode

I have only seen this done with high concentration sulfuric acid. Am i just giving up the speed it will plate off or will it just plain not work? How high must the concentration be for it to work well?

If no one knows I will have to run some experiments!

 

[Yggdrasil]

High concentration Sulphuric acid will not attack copper,
but as the concentration comes down it will start to eat away the copper in the pins/basket and so on.
Too warm concentrated acid will attack the copper as well.
So high concentration(best in the 90s, but I think I have seen recommended over 60 percent) and as cool as practical are the guidelines.

It is possible to evaporate out most the water from battery acid,
but it has a lot of risks since hot sulphuric acid is really nasty stuff.
Good quality glassware and very well ventilated area is a minimum, I guess.

 

[g_axelsson]

I don't know exactly where the limit for sulfuric acid composition is, but 60% is way too low to work. 90% or higher is the recommendations I've seen.
When the acid is too weak the cell starts to eat base metal instead of gold and it is quite distinct when it happens. I was surprised how fast it went from a working cell to now work at all.

Yes, you can evaporate off the water from sulfuric acid, but it will be a weak sulfuric acid that is evaporating, not just water. Just a well ventilated place isn't enough. Either outside or in a working fume hood is the only safe places. Best of all would a fume hood with a scrubber be, the fumes will affect anything in the vicinity.

Göran