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topic 6262

Silver refining problem: Removing copper from silver nitrate


(2000)

Q. In the process of refining pure silver, we end up having a lot of copper in the electrolyte (silver nitrate). The efficiency of the process diminishes as the copper concentration increases in the bath. I am wondering if there is a process where I can regenerate the electrolyte (AgNo3) by removing the excess copper from the solution.

I would greatly appreciate anybody's help.

Thank You.

Ajit Menon
- Alden, New York, USA


(2000)

A. Dear Ajit,

Selective removal of copper from AgNO3 can be performed by ion-exchange, provided the pH is not below 1.5. The key will be to minimize silver loss by extensive wash of the resin or by use of a continuous counter current ion-exchange system (ISEP).

Ruud Gerritsen
Recomet B.V. - Simpelveld, Netherlands


September 16, 2012

Q. I noted the suggestion of Mr. Gerritsen to use a counter current ion-exchange system (ISEP). I have refined 80/20 Ag/Cu for a while in a AgNO3/HNO3 bath, but I think I have got to the point of copper contamination of the electrolyte, like the original poster. Is there a way to electrically remove the copper and keep the AgNO3?

Thanks,

Tom, who just started this stuff and finds it fascinating.

Thomas Schmidt
- Tuckahoe, New York


(2002)

A. Have you thought of precipitating the Ag with HCl and resmelting with Borax [linked by editor to product info at Amazon] and flour to obtain about 95% Ag which you can redissolve in HNO3 to get your electrolyte?

Edmund nkrumah
- Accra, Ghana



Moebius cell technique leaving impurities in refined silver

(2002)

Q. What could be the cause of having impurities in refined silver using the moebius cell technique, when crystals obtained have been thoroughly washed with deionised water?

Edmund Nkrumah
- Accra, Ghana



Only achieving 50% silver recovery; need 90-95%

May 8, 2009

Q. We are facing the problem of silver recovery from silver and copper mixture. We are refining the silver metal as silver chloride and copper as copper cathode, by electrolyzing process.

We get silver chloride from the electrolytic solution by addition of HCl. Rinse we filter the silver chloride from the solution, After the many water wash, we melt the silver chloride by addition of borax and carbon powder. But we are getting the silver recovery only 50%.

Please help me to get about 90 to 95 percent recovery of silver metal at least.

Please reply us as soon as possible.

Thanks.

Digant Ashra
hobbyist - Rajkot, Gujarat, India


November 8, 2014

A. If your silver nitrate solution gets saturated with copper, cement the silver nitrate out onto copper, you will get elemental silver, and one could get the copper nitrate out by cementing onto iron (after washing and separating from the cemented silver), you're left with iron nitrate and copper oxide, I believe, but the cemented silver is clean enough TO MELT and make new electrolye again. DON'T put the cemented powder back into nitric. Nitric reacts explosively with metal powders, because of the large surface to act on!

Cementing onto copper:



wikipedia
Silver Chloride

I'm not an expert in refining, merely a student of this interesting science, but that's what I would do to get rid of silver electrolyte saturated with copper. Copper is close to silver on the reactivity series, =>
with only mercury and tungsten in between. Pt and Au will not be in a nitric solution, so pretty pure Ag is to be expected. Why bother making AgCl first and having to melt and waste borax?

Use this info (and everything else you find on internet, for that matter) AT YOUR OWN RISK!, it's purely for theoretical purposes, be educated and sure of what you do.
read MSDS! be safe!

wikipedia
Reactivity Series

Melting silver chloride will produce chlorine as well =>

Martijn Ehlers
- Zeeland, the Netherlands


January 30, 2015

A. To recover silver from silver nitrate solution I prepared a reagent which is directly added into silver nitrate solution. No need to precipitate as silver chloride. It works nicely and the purity of Silver is 9999.

Daulat Bhosale
- Bangkok Thailand


February 13, 2015

Q. Daulat,

Dead keen to know what your reagent is -- organic?

AG

Andrew Gowans
- Fairfield, Australia


February 15, 2015

A. Yes. The reagent is a mixture of three organic compounds. Watch the video on you tube. Recovery of silver from silver nitrate solution.

Daulat Bhosale
- Bangkok Thailand


August 19, 2015

Q. Daulat Bhosale,

Can you please give us the address for this youtube video try to look for it but did not find it.

Thanks

Baruch Katz
- Cape Town RSA



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