NEMO-Chemistry
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Silver from silver plate
Is the electro method the best way to recover silver from EPS?
I have collected alot of it, some says nickel on it and I have a thing for Nickel and Silver at the moment!
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vmelkon
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React with nitric acid to get a salt solution. If there is iron or similar element, the Ag+ ions would get reduced back silver. When the entire metal
is reacted to obtain a nitrate solution, add a chloride solution to precipitate AgCl.
Then exposure to light or heating it would reduce the Ag+ to silver and the chlorine liberates into the air.
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weilawei
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Also, direct heating of AgNO3 will reduce it to elemental Ag. This can be much faster and easier.
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NEMO-Chemistry
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So the base metal dosnt react? I am not too sure what they use as a base metal on old spoons etc
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MrHomeScientist
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The nitric should dissolve everything, including the base metals. Adding NaCl precipitates only AgCl, since all other metal chlorides are soluble.
This purifies the silver of whatever other metals might be present.
For example sterling silver is an alloy with copper: after dissolving in acid and adding the salt, you're left with solid AgCl and a solution of
copper nitrate.
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phlogiston
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The conversion of AgCl to Ag by light alone is very slow and very uneven because light doesn't penetrate very deeply into the powder. A much quicker
method is to add concentrated NaOH to form AgO. This can optionally be converted into metallic Ag by adding a reducing sugar (corn syrup is typically
used), or it can be decomposed into Ag directly by heat.
Another method to get the silver out of the nitric acid solution is to add metallic copper. If you have an excess of acid, at first the copper will
dissolve. But if you add an excess of copper, it will then reduce the silver, yielding metallic silver directly. Copper is not able to reduce the base
metals.
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NEMO-Chemistry
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ok thx i understand now
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unionised
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The big problem is you waste a lot of acid dissolving the base metals.
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unionised
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Quote: Originally posted by phlogiston  | The conversion of AgCl to Ag by light alone is very slow and very uneven because light doesn't penetrate very deeply into the powder. A much quicker
method is to add concentrated NaOH to form AgO. This can optionally be converted into metallic Ag by adding a reducing sugar (corn syrup is typically
used), or it can be decomposed into Ag directly by heat.
Another method to get the silver out of the nitric acid solution is to add metallic copper. If you have an excess of acid, at first the copper will
dissolve. But if you add an excess of copper, it will then reduce the silver, yielding metallic silver directly. Copper is not able to reduce the base
metals. |
Ag2O (Not that it matters much)
You can get the same effect by mixing the AgCl with sodium carbonate and melting it.
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NEMO-Chemistry
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Not a bad way to 'use' some Nitric acid then  .
Especially as you wouldnt need alot of silver or silver nitrate to tally with your stock list.
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vmelkon
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I suppose you can collect the other metal nitrates.
Heat it with conc H2SO4 to get some nitric acid back.
And if you really want to continue, heat the metal sulfates to some high temperature to get some SO3 vapor. Direct the SO3 into some low conc H2SO4.
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We must attach the electrodes of knowledge to the nipples of ignorance and give a few good jolts.
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