# Silver 3 ways !



## kjt124 (Feb 5, 2013)

Hi guys! I've been playing with a bit of silver (just melted my first beautiful ounces :mrgreen: ) and I just came into some things I wanted to ask you guys about.

First off is probably very easy (and I am pretty sure I already know the answer, but...) - I have about a pound of reagent silver nitrate crystals (very old jar). I am guessing the preferred method is to dissolve into solution and drop with copper like usual, right? There is likely no good way of going direct to silver like you can from silver oxide? I know it melts before it decomposes and this sounds possibly like a messy operation. Thoughts?

Next one I am having trouble finding much reference at all to on the forum... I have about a pound of silver sulfate. In fact it was the first time I can remember hearing of such an animal. Does anyone know what I would do to get the silver divorced from the sulfate?

Also, another new one on me... I have several small bottles of 4 molar potassium chloride solution that says it is saturated with silver chloride. Obviously the potassium chloride helps the silver chloride dissolve, but does anyone know to what extent? Does anyone know the best route to get to the silver?

I have a few of the usual chemicals (HCl, Nitric, Caustic), but no real hot plate ability (a bit too windy a winter for the side burner on the grill to be effective).

Thank you to anyone who can chip in!!


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## nickvc (Feb 6, 2013)

The silver sulphate from what I can understand is reduced from hot concentrated sulphuric acid by cooling and diluting and one easy method to then convert it to silver metal is to wash that sulphate with hot ferrous sulphate solutions, copperas, this produces a ferric sulphate solution and with good rinses and filtering possible 999 silver which can then be melted.
Your silver nitrate can be used in a silver cell if you are going to refine silver at a later date it will save you some nitric and no fumes...win win in my opinion.
The potassium chloride I'm not sure about but will try and do some research for its treatment and recovery safely.
Hope this helps.


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## kjt124 (Feb 6, 2013)

Excellent - that sounds easy enough for the Sulfate. Just a quick clarification... when the ferrous sulfate starts to go brown, that means it is well on its way to ferric sulfate already, right? I have a few bottles of varying degrees of quality...

Also, I assume by hot, it would be sufficient to put a kettle on the stove to mix up the copperas, right? It shouldn't need to be screaming hot I am hoping.

Thank you for helping me out nickvc


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## nickvc (Feb 6, 2013)

I think the idea of a hot solution is that it speeds up the conversion into metallic silver, it was done in a funnel and then put through a vacuum filter and rinsed with water in the one example I know of. Use fresh ferrous if you can,green not brown, as it forms ferric sulphate in the conversion, and thats important to avoid loses in melting. All you have to do now is find a use for the ferric...


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## element47.5 (Feb 6, 2013)

I second the motion to keep the silver nitrate for a silver cell, meaning do NOT try to reduce it to metallic silver.


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## kjt124 (Feb 6, 2013)

I have to admit I was playing around with that idea as well - it is ACS purity - would be a shame to 'waste' it.

Not to mention I have some silver I dropped with copper powder (with completely incorrect and careless math...) that is pretty dirty. The top of the button on those has a distinct dark glaze with hints of green in it... gee, think there's some copper in there? I could use that as my first silver cell trial while proceeding with confidence about purity of electrolyte and such.

On that note - what is the best thing to do with copper powder? I have about 2 pounds of VERY fine copper powder (Fisher Sci I believe). Would it be a good idea to torch melt it into slugs to drop copper with? Would it be a good idea to use as a starter on silver drops then finish off with copper tubing / bus bar? WHen I was melting my 'dirty' silver there was the green tinged flame indicating I am burning off copper. How well would the copper powder even melt into slugs? Not worth the fuel?


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## Lino1406 (Feb 7, 2013)

Alternative methods:
1. Silver sulphate. Can be cemented with 15% sulfuric
acid and zinc. Recommended - stirring
2. Silver nitrate. Dissolve in distilled water and
precipitate silver oxide with caustic, ready for
melting
3.KCl saturated with silver - negligible.


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## kjt124 (Feb 8, 2013)

I'll try the Sulfuric route - looks like none of my ferrous sulfate is going to do the trick  

So KCl doesn't hold onto much AgCl... I was afraid of that. Maybe I'll play around with it a bit on pH and see if I can get it to an oxide or just hold onto it until silver is worth more.

Thanks Lino1406.


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## kjt124 (Feb 19, 2013)

So, I think I am finally wrapping my head around this... it's been a long time since I had chemistry...

I found a jar of ferrous sulfate that still looked pretty good (sort of a light jade color) and am seeing how that is working on the silver sulfate. Unfortunately due to hastiness I didn't prep the silver sulfate very well and will need to further bust up some very hard chunks. Seems to be working as intended though - getting lager colored liquid (presuming ferric sulfate), decanting and adding water again...

However, what is starting to make sense to me is how the electromotive table works in conjunction with oxidation state. Things are becoming more clear. Since Iron is higher than silver on the electromotive chart and since the ferrous ion is in a lower (perhaps higher - like I said, a long time since inorganic chem) oxidation state than the silver, the iron pulls the sulfate ions off of the silver to reach a more satisfactory oxidation state. I am sure the chemistry guys can put this in far more professional sounding terms  

Anyway, if I am correct about this line of thinking I could have probably done a similar reaction with cuprous sulfate, but it may have needed a little sulfuric to kick start it?

Along the same idea (might be talking nonsense here), would ferrous chloride be a viable reducer for silver chloride?

Thoughts?

Kevin


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## butcher (Feb 19, 2013)

Along the same idea (might be talking nonsense here), would ferrous chloride be a viable reducer for silver chloride?
Thoughts?

Electron transfer, for one metal to reduce from solution (gain electron), another metal or substance will have to be oxidized (lose of electron), I would use elemental iron and the sulfuric acid method to convert the silver, the iron would give an electron to the silver chloride, reducing the silver to elemental metal silver powders, the iron now missing electrons would join with the chloride from the silver to form iron chloride, (iron would also form iron sulfate in a similar manner), the solution will become a combination of iron sulfate and iron chloride as iron is oxidized by giving up its electron.

I do not think ferrous chloride (already a chloride would give electrons to silver chloride), or at least not effectively enough to reduce the silver, and oxidize the ferrous chloride.

Reactivity plays a role in the electron transfer, as well as does the metal cation and the acidic salt anion involved.

In the formula AgCl + FeCL2-->, I do not see where any thing would be reduced or oxidized, I also do not see where a displacement reaction would occur, although I can be wrong I say no reaction would occur.


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## Lino1406 (Feb 20, 2013)

beware of Fe2O3 appearance (especially with FeCl2
but with FeSO4 too)


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## kjt124 (Feb 21, 2013)

I am hoping that would pretty easily discernible by color? It would be the strong and characteristic red instead of the lager color right?

If that begins to form, drain and add fresh water?


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## Lino1406 (Feb 22, 2013)

Fresh water will not help. Just beware of needing
additional purification


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## kadriver (Feb 22, 2013)

kjt124 said:


> Also, another new one on me... I have several small bottles of 4 molar potassium chloride solution that says it is saturated with silver chloride. Obviously the potassium chloride helps the silver chloride dissolve, but does anyone know to what extent? Does anyone know the best route to get to the silver?



I am not up on the chemistry, but I do know that potassium chloride is soluble in water, but silver chloride is not soluble in water.

If you have silver chloride in solution, then the solvent has to be something other than water.

The only thing that I know of that will dissolve silver chloride is ammonia - if your soluion is ammonical, then you might be able to add HCl to precipitate the silver chloride and get it that way.

I'd put 1 ml of the solution in a test tube and add a few drops of HCl and see what happens. If you get a thick white precipitate, then thats your silver chloride.

But I don't know if the potassium chloride will precip out with it. If it don't, then you could filter out the silver chloride, or just wash with tap water - settle - wash with tap water - settle - repeat for about 6 or eight times and your silver chloride would be clean of potassium chloride.

Keeping the silver chloride moist (don't let it dry or this won't work) you could add NaOH (red devil lye) to the silver chloride to convert it to silver oxide. It must be stirred vigorously until the pure white silver chloride is jet black.

Then just add some regular table sugar to convert the silver oxide to pure silver metal - it will be silver powder.

Rinse and settle repeatedly until all the NaOH and sugar is gone, dry and melt for silver that should be very close to 999.

Hope this helps.

kadriver


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## kjt124 (Feb 22, 2013)

That's a good call KADriver. I'll try the HCl.

Yeah, I am getting more familiar with Silver Chloride. It is pretty unfavorable to work with, but each small batch goes slightly better.

Just as an aside... What the heck is Drano (and similar products) made out of now??? Some sort of green pearls with metal flakes in it (been a lot of years since I've used the stuff on a drain). I'll look for Red Devil Lye.



> Fresh water will not help. Just beware of needing
> additional purification


 Lino1406

I would assume a nitric digestion and the normal routes thereafter would be acceptable? Or would you go straight to a cell after a melt?

Thank guys,
Kevin


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