Non-Chemical Plating pins

[Riyoso]

I have over 50 kg of pins im trying to plate out using 2 power supply's from old pcs and its been plating for a week and the results are very poor. No1 should i use agitation while plating as it keeps the solution fresh and No2 how much sulfuric acid is mixed per ltr.

 

[patnor1011]

give us bit more info. also you are plating or de-plating /socalled reverse plating/ ?
i hope you are not doing all 50kg in one go. do you have pictures of your set-up ?

 

[Riyoso]

Sorry cant send any pics at the moment and i am deplating not all 50 kg at one time i only have a 10ltr tank and i only have a anode basket which can support 300grm of pins at ones and i use flat copper plates as my cathode's. I have for the past week only retrieve'd gold foils mixed with tin and alot of copper which does not stick to the cathode and drops into selution and no black oxide precipitates.Any help please whould be great and i dont want to use nitric acid anymore becaus the process is a mess.

 

[Harold_V]

Do you understand that the sulfuric acid required must be concentrated? If you are using diluted sulfuric, I expect you will not achieve the desired results. Your question about how much sulfuric per liter leads me to believe that you are using it diluted.

Harold

 

[goldsilverpro]

What Harold said. Another clue that you're using dilute sulfuric is that you're ending up with gold foils. You're dissolving the copper and not the gold. You need to start over and use concentrated sulfuric (about 95-97%, by weight). It will speed up the reaction if you add about 5% water, by volume, to the concentrated sulfuric. With this, the copper and other base metals won't dissolve. The gold will be stripped and will form as a black or dark brown powder. Agitation should not be necessary.

Depending on the current used, it should take only a few minutes to strip. However, if the pins are in a pile, the ones on the inside of the pile will be shielded from the current and either won't strip or will take a very long time. You need to break up the pile in some way as the parts are stripping. You can try using a stirring rod. Ideally, you could tumble the parts. Recently, someone posted a series of photos and instructions for a tumbler that you could make.

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=5092&hilit=sulfuric+tumbler&start=0

 

[Riyoso]

I am using 96% sulfuric acid Harold and thanks for the advice u all i managed to get it write by only ading some sulfuric acid.

 

[AuMINIMayhem]

I have over 50 kg of pins im trying to plate out using 2 power supply's from old pcs and its been plating for a week and the results are very poor.

:idea: I hope this doesn't come across the wrong way, but sometimes people overlook the obvious.. the power supply you're using.. it IS DC not AC current, right?.. if you're using an AC power supply, it'll never happen..

just throwing that out there.. 8)