# Silver chloride mix with tin chloride,needed help.



## Joko sulistyo (Jan 23, 2018)

Hello,all.
At first,I want to say many thanks to you all.In this great forum,I can learn about recovery and refining precious metals.
Today I have a question about the way to separate silver chloride that mixed with tin chloride.
I have many silver chloride in my stock pot.unfotunately,they mixed with tin chloride.I don't know how to separate well.
I was try to dissolving the silver chloride with dilute hno3 but it didn't work.And then I try to convert mixed silver chloride to elemental silver using NaOh and sugar.
At this step,it look good.I get grey black cement like as elemental silver.But the silver is difficult to melt.the silver won't melt.They likely only ash.
What wrong with this?Anybody can help?
Thanks.

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## nickvc (Jan 23, 2018)

The one suggestion I can give you is to filter the mixed sludge from the stock pot and then incinerate it, heat gently to red heat for an extended period, crush the resulting material and then place in a beaker and slowly add Hcl, this should remove the tin and leave the values including your silver chloride for later recovery.
This process may well give you losses and will need doing with good extraction especially the incineration when some silver chloride and possibly some gold chloride can and will volatize.


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## anachronism (Jan 23, 2018)

Alternatively doesn't Tin (II) Chloride dissolve in water? If that's the case could you not filter the solution as it is, and precipitate any silver from that solution separately, then boil wash the remaining particulate a few times to remove the Tin Chloride. After this you could reduce the Silver Chloride in one mass and dissolve/precipitate as normal to get metallic silver.

I've not had to do this myself so it's guesswork from me but it seems logical.


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## Palladium (Jan 23, 2018)

He's mistaken.
He has SnO2, not SnCl2.
It's white just like the silver chloride.


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## Lino1406 (Jan 23, 2018)

There are several ways of separating tin dioxide and silver chloride, e.g.:
dissolve silver chloride with thiosulphate and/or ammoniac (leaving the SnO2 intact)
dissolve tin dioxide with concentrated fluoboric acid


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## g_axelsson (Jan 23, 2018)

Any tin(II) chloride in a stock pot is probably oxidized into a form that isn't soluble any longer.

Incineration of the tin silver chloride mud isn't so smart either, the silver chloride would melt or form a toxic smoke. This only leads to more losses.

What I would try faced with separating tin chloride oxidized into hydrated tin oxide of unknown state mixed with silver chloride is :
- First convert the silver chloride into silver oxide with concentrated NaOH. This will also affect the tin oxide / hydroxide but exactly how I don't know. It might even dissolve some of the tin as sodium stannate that can be removed in the next washing step.
- Wash out any excessive NaOH and possible soluble sodium stannate.
- Dissolve the silver oxide with nitric acid. Any tin still in solution will be oxidized into an insoluble tin compound.
- Decant off the silver nitrate solution with several repetitions to get most of it, filtering tin compounds is a nightmare.
- The silver nitrate can then be converted into metallic silver in several different ways.

For anyone interested in the chemistry of tin, I have collected some links here.
http://goldrefiningwiki.com/mediawiki/index.php/Tin
http://goldrefiningwiki.com/mediawiki/index.php/Metastannic_acid

Göran


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## Palladium (Jan 23, 2018)

Hummm...

Could you not dissolve the Tin in a highly alkaline solution making it water soluble, while at the same time converting the silver chloride to silver oxide? With the proper washing i would think you could remove the majority of the tin. Then when you melt the silver and go to the cell the tin will again be precipitated in the basket there by separating that last little bit?


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## Palladium (Jan 23, 2018)

You beat me by 6 minutes. I see your post now Göran.


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## g_axelsson (Jan 23, 2018)

It happens to the best of us. 

Göran


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## Joko sulistyo (Jan 24, 2018)

Thanks for reply my post.I guest the contaminant that mixed with the slugde is not only tin chloride.maybe metastannic acid too.Because they'are look grey and very difficult to separate.try to filtering them is really a nightmare for me.

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## Palladium (Jan 24, 2018)

Do you run just one source for your silver or does it come from many sources? Like silver jewelry, silver contacts, silver brazing, and so on.


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## Joko sulistyo (Jan 25, 2018)

Thanks,Palladium.The sludge come from many sources.silver brasses,contact points,silver plated cables,some cellphone boards,industrial control panel boards,no jewelry at all.Just for e-waste.I was collect them for years.

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