# How to refine solder to get silver



## copperkid_18 (Dec 19, 2010)

I was wondering the process on how to get the silver out of old circuit boards' solder? Or even the chems needed. Thanks!


----------



## butcher (Dec 19, 2010)

http://en.wikipedia.org/wiki/Parkes_process

It can be done chemically also, using acid peroxide, and solubilitys of salts, but challenging.

I would just save up solder melt to bars and use them or sell them, it would not cost you so much.


----------



## copperkid_18 (Dec 19, 2010)

Ok, thanks! At the moment im doing a little experiment- I have 1 gram of recovered solder in some HCL... It is putting of 1000's of little bubbles and there are now little black flakes floating around in the jar- (Are these possibly the silver?) Thanks, Kobe


----------



## butcher (Dec 19, 2010)

silver and lead are insoluble as chlorides (both white powder), tin is soluble (but makes filtering nightmare's).
silver chloride is insoluble in cold or hot water, but lead chloride is insoluble in cold water but slightly soluble in boiling hot water.
silver chloride can take time to settle.

boiling the silver and lead chloride powders in water, lowering to hot but no boil giving time for silver to settle, decant hot lead chloride solution (on cooling will form lead chloride salt again).
this makes it sound simple, it will not be so simple, and may need several re-crystalizations to separate totally, silver will settle in hot solution but only slowly, so keeping the temperature up so lead is soluble and letting silver salts settle is challenging.


----------



## copperkid_18 (Dec 19, 2010)

so what you are saying is that the silver will drop with pure lead in the bottom as a white powder? Or am I completely misundestanding you?


----------



## butcher (Dec 19, 2010)

correct white powder.


----------



## copperkid_18 (Dec 19, 2010)

Sorry If I sound dumb repeating this but you are saying that I have my solder in the HCL and soon the lead and silver will be precipitating out as a white powder?


----------



## butcher (Dec 19, 2010)

yes :wink: white powder can be salts of lead chloride and silver chloride.
HCl alone may not dissolve very fast, some peroxide will help, heat always speeds hings along.

here another thing say I have these white powders in water sitting in the sun, the silver white powder will turn kinda purple, the lead powder stay white, this is a principle used in photography.


----------



## copperkid_18 (Dec 19, 2010)

Thanks! I dont see any powder yet.... How long will it take?


----------



## butcher (Dec 19, 2010)

solder is not real easy to dissolve, these are not real active metals, heat helps. sorry I do not time reactions.


----------



## copperkid_18 (Dec 19, 2010)

Ok, well the solder is 3/4 way dissolved as of now and no powder... It actually is dissolving pretty quickly


----------



## butcher (Dec 19, 2010)

these powders can take time to settle, especially if acid content high, and oxidizer bubbles (peroxide keeps them stirred up), after it dissolves let settle a while. I gotta go now will check back later to see how this goes.


----------



## copperkid_18 (Dec 19, 2010)

Thanks!


----------

