The authoritative public forum
  for Metal Finishing since 1989
  

 

-----

Solubility of silver chloride in copper bath

I am trying to electroplate silver (>1%, or >0.0024M AgNO3) from copper sulphate ⇦ this on eBay or Amazon [affil links] bath (0.6M CuSO4.5H2O and 0.3M H2SO4)) that contains chloride (50 ppm). Silver chloride is very insoluble in this solution. What can I do to make silver chloride soluble in my copper electrolyte? I thought about chelating silver(I), but I can not find right chelating agent (most agents react with copper(II) first).

Igor Volov
Ph.D. candidate - New York, New York, USA
September 20, 2011

---

Hi, Igor.

Sorry, but I have little idea what you are saying. Maybe if you could explain why you are trying to do what you're doing I could understand what you are trying to do. Thanks.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 21, 2011

My goal is to co-deposit copper and silver (i.e. plate copper-silver alloy) metal with about 1% Ag content. For this I must use copper sulphate bath that contains chloride ions (chloride ions are very important). But, as soon as I add silver salt (silver nitrate), silver and chloride precipitate. Precipitate can not be tolerated in my process.

Igor Volov
- New York, New York, USA
September 23, 2011

---

Hi, Igor. This sounds like a formidable problem because silver ions in solution with chloride ions will indeed precipitate as silver chloride. I suppose that if the silver is complexed with cyanide or another complexor, there might be some chance of success if the mixed solution is used quickly. Mixing cyanide with acid evolves deadly HCN gas, so this should be tested only in very small quantities and behind a trusted lab hood. The site's supporting advertisers EPI / Electrochemical Products Inc. [a finishing.com supporting advertiser] and Zinex offer cyanide-free silver plating processes that you could inquire about. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 24, 2011