# deplating silver plated microfoils of 20 to 25 microns



## chemguy (Oct 31, 2013)

We are trying to deplate/strip silver plated micro foils of size 20 to 25 microns. 

We tried two process: 1. Cyanide and Caustic Mixture: Were successful with the process and got good results but we were not able to process bulk quantities. 

2. Sulphuric / Nitric Mixture: We are able to process bulk quantity but we are facing problem in handling the material moreover the solution is also etching the copper.

In both the procedure at the end we are getting the stripped material as oxidized material.


----------



## niteliteone (Oct 31, 2013)

Pictures of the material and step by step description of your process would help. 8)


----------



## rickbb (Nov 1, 2013)

It sounds as if your silver is plated on copper, is that what I'm reading?

Could you not use the AP process to disolve the copper underneath the silver and then filter out the silver foils at that point?


----------



## goldsilverpro (Nov 1, 2013)

Many people mistakenly use the term "microns" when then should say "microinches". Ignorant people use these terms interchangeably. Actually, a micron is 40 times thicker than a microinch. Although not impossible, it would be unusual to find plating 20-25 microns (800-1000 microinches) thick unless it were for a special application.


----------



## lunker (Jan 3, 2014)

Hope this dosen't seem like a dumb question but, If copper plated material is roasted. To convert the copper base to a oxide. could the silver not be removed with a solution of Hcl acid and some gentle tumbling? Having the copper go into solution and leaving the silver as a insolube residue?


----------



## butcher (Jan 3, 2014)

If you just had copper and silver powders that may work, but not with silver plated copper, you would just solder the silver onto the copper the silver coating would protect the copper from oxidation.

copper pipe does not really oxidize that much with heat from a torch anyway, you can heat copper pipe up cherry red and still easily braze a low silver brazing rod to it (normally called silver soldering).
flux is helpful in silver soldering copper but not necessary if the copper is cleaned well.

Silver will passivate and form a protective coating of AgCl with HCl.

Basically that idea will not work.


----------



## NeMonstr (Jan 4, 2014)

There are alternative methods. This thiosulfate leaching, ammonium thiosulfate leaching, sulfite leaching etc. Need to experiment to find the best for you. I use sulfite electrolyte at the moment.


----------

