vibbzlab - 1-3-2020 at 22:56
I thought I Will just give a small write-up about the process I did to extract pure Silver metal from an old Silver jewellery
If you don't like reading you can directly watch the process video. Link below
https://youtu.be/y3CEkHz_P9E
Continue reading..
So last day I was in my garage and I was cleaning a wardrobe there and found a small silver ornament. I was told it's my grandmother's and she's no
more now and I was allowed to use it in my lab. So I decided to extract silver metal from it
Silver ornaments are actually made of an alloy called Sterling silver which contain about 92.8% silver and rest of it mainly contains copper and a
very minute amount of nickel.
The procedure I used is Single displacement reaction
I first dissolved the chain in concentrated nitric acid. The reaction didn't go as I expected it to be because when I put the silverware into acid
there was a spontaneous reaction and too much nitrogen dioxide fumes formed and the solution turned green. I didn't know the ornament had this much of
copper contamination in it. Anyway this is a 30year old jewellery. I cannot complain. So the silver chain has way too much copper than I expected.
After dissolving the Chain in acid I just did a simple gravity filtration to remove any interacted debris. I had added excess acid to make sure
nothing useful gets left behind.
Next step is to seperate out Silver metal.
As silver lies below Copper in reactivity series it was pretty easy and I used some copper metal pieces to separate out silver. I kept on taking out
the silver metal and reintroduced the copper metal to remove any last bit of silver remaining in the solution. Finally when nothing was able to be
precipitated I realised the reaction is complete and I discarded the Solution.
Next step is to wash the Silver precipitated. I washed around 15-20 times with demineralised water and then dried the product.
That was about the extraction of silver metal.
Now for synthesis of silver nitrate
I used the silver metal and added nitric acid into it .
The reaction was pretty fast as the silver was in powdered form and pretty much increased surface area for it to react.
After the metal completely dissolved I was left with a transparent solution which I then crystallised by boiling off excess liquid . The salt was
still contaminated with copper. Anyway the product seems legit and it started to reduce by the time I dried it in filter paper ( picture given )
So yeah that's the whole process. The video link to this whole process what I did is given below
https://youtu.be/y3CEkHz_P9E
Bezaleel - 2-3-2020 at 04:07
That still looks like a large amount of silver nitrate. I did a similar experiment dissolving a silver spoon, and the solution became dark green.
After a while I was left with a copper spoon, so I concluded that the spoon was not really silver, but only silver plated. The amount of silver I
recovered was less than 1 gram for the 15 gram spoon.
One of my conclusions was that the cheapest way to get to silver compounds is by using silver coins, which can be obtained at market price with 99.9%
purity. For silver and gold coins you don't pay VAT since they're coins and therefore they count as currency. (You do pay VAT over silver in any other
product.)
You might try to further purify your silver compound by precipitating the silver as silver(I)chloride. Judging from how white it looks, my guess is
that it must be reasonably pure.
vibbzlab - 2-3-2020 at 04:09
It's pretty pure. I will try recrystallization one more time and then I will try the tollens test. Let's see if I can get a good mirror
Herr Haber - 2-3-2020 at 05:44
By the book 
If there are insolubles and you used excess acid I recommend to boil it.
Some insolubles are not insoluble anymore in hot nitric acid.
Silverware is usually between 80 and 95% silver.
Oh, shame that you discarded the solution. I'd bet there was still silver in it. I usually dip a copper bar for 2 weeks in my spent solution.
There's always a bit of silver left even after that.
It can be easily demonstrated by adding a pinch of salt or HCl to your solution.
vibbzlab - 2-3-2020 at 05:49
I tried sodium chloride and there was no white precipitate
Bezaleel - 3-3-2020 at 04:09
Was there a precipitate at all? Whenever I made silver chloride, it always turned brown sooner or later by light.
From the top of my head, I think the solution should not have too low pH for AgCl to form; silver chloride seems ot be (at least a little) soluble in
HNO3, link.
vibbzlab - 3-3-2020 at 04:51
Aaah maybe that's a possibility anyway I am happy with the yield which is more pure than I expected it to be l