Processing SilverPlate With H2O Cell

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edit: page 6 and 7 seem to give a quite good explanation and some answers http://www.dtic.mil/dtic/tr/fulltext/u2/478632.pdf
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"Review of fundamental investigations of silver oxide electrodes" Must Read!

Well, the secret of the tab water silver stripping cell is, it is a badly constructed silver battery (as a stripping cell perfect) going to be charged and eventually discharged and they knew it already in 1967 :lol:

Left over is the question, why the base metals do not contaminate the silver too much. I guess they get passivated to some degree...if they do anything at all.
 
Washing the brown-gray-black mud with HCl leaves gray, heavy powder, obviously metallic silver. The solution gets slightly green like copper or/nickel. Gas production occurs. Liquid is clear, no AgCl visible! :shock:
edit: finally found silver chloride, there is gray (probably) elemental silver AND powder with a violet tone

When the mud is put in HNO3 instead of HCl, it dissolves, as expected, completely.


.All I read and all I saw in my experiments is confusing me right now. It makes only sense to me, if the metallic silver is made by reduction - maybe caused by the dissolution of the contaminants. Or I have to start from the beginning again.

It works very well and I hope that some more brains will try to break that nut. Only when we are sure about the important reactions in this process, we can find out how to optimize it even more.
 
Today I tried this with pure zinc electrodes in one jar and copper in another. Zinc forms a white powder, cloudy, similar to zinc hydroxide or finest oxdide. Copper forms a light blue powder similar to copper hydroxide. When I added pure 0.1M AgNO3 solution, it became a brown precipitate in both electrolytes.

Again gas only on one of the electrodes. Precipitate at the other.
 
I think I would try an experiment with these three individual metals all connected to the anode, suspended separately in the same distance from the cathode, just to try and see what maybe happening, if one metal is consumed before another, if one metal to plates to another, if gasses form predominantly on one metal easier than another...

Another experiment similar to the above, using only a copper and a silver anode, without zinc (which unlike copper or silver can displace hydrogen).
 
Good idea! I'll try that.

Until now there never occurred any visible gas production at the anode. Only solids built. There should be oxygen after all chlorine is removed, but it obviously gets bound by some or all of the involved metals.
At the cathode always gas production visible, with inert cathode, copper cathode or zinc cathode. This should be H2 though I haven't tested.
 
I have left the washed silver in HCl, now it has become a homogenous slightly gray, almost white powder. Would fine elemental silver powder convert to AgCl after longer exposure?

I have a feeling of, that it could be both, very light gray silver blended with AgCl. I will test with sunlight later.
 
I suspect pH will be different in the reactions of only silver or copper in a cell, compared to a cell, which involves zinc, as zinc, will displace hydrogen of the electolye chemically (possibly making the electrolyte more leaning towards becoming a hydroxide).

Current, which is used, will also play a role on the pH of the solution, as well as the pH which can also change with the time the cell is operated as gases leave the solution…

Water can act as acid or a base, when we split water with electrolysis; we are in effect splitting acid (hydrogen) and the base (Hydroxide), what gases leave the cell can also effect the cells electrolyte or pH.

I can see where just by connecting two or more dissimilar metals in an electrolyte (acidic or basic) we create a cell (a battery or galvanic cell), with two or more metals joined at the anode by a wire there can be a cell created between these at the anode, basically we have a cell within a cell, with reactions occurring at the anode itself, electrically and chemically.

Having a mixed metal anode we are adding to the complications of reactions going on in the cell, many factors can be playing a role here.

I am finding it hard to describe my thoughts here, but maybe you can get the idea.
 
I am finding it hard to describe my thoughts here, but maybe you can get the idea.
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Yes, I understand that, you told me before and I try to have it in mind while I examine this cell. Therefor I am not sure if I have elemental silver, different silver oxides/hydroxides/hydrates or a blend of all. Probably it is a blend, which even alternates under the process until a stable equilibrium is reached. And they alternate again, as soon as any variable is changed.
 
Cleaning the powders with HCl has been a poor choice, I think. Next time I would try dil. H2SO4 to avoid formation of AgCl. Only a little silver will get dissolved by H2SO4 and can be precipitated later.
 
Thanks so much for keeping this thread active. It is thread that caught my interest many months ago, but I had no understanding at all of the process involved and knew nothing of the refining of silver. The little I have learned over the months have peaked a new interest at the learning stage for me.
 
Instead of using tap water, which creates some AgCl and some NaOH to a pH of 9-10 in the beginning, it might be an idea to start with distilled water and raise the pH to 9-10 by some drops of NaOH. I haven't tried this, but it seems to be the logical consequence of the observations and the text I linked.

I haven't any data yet about the yield efficiency. I assume, that the more silver has been stripped, the more impure the gained oxides will get. As someone stated before, it is hard to determine, when the point to stop the process has come.

After all reading and experimenting I came to the conclusion, that the silver is mainly represented by Ag2O (and some AgCl if you use tap water). The contaminants seem to be comparably low, but definitely present.

Instead of washing the slimes, it might be better to dissolve them straightly in HNO3 and cement on a piece of copper from the dirty solution (less work, quite pure product).
 
many thanks to Mod the world and solar and all the rest, newbie or expert who helped.
I am a newbie and have been doing a lot of reading but was not happy about jumping in at the deep end.

I have a quantity of silver in lots of different forms, plated on several base metals, thick blocks of copper, some solder with lead and tin and who knows what else and did not want to create a big mess but would like to be able to recover the silver and maybe even some of the base metals, it all sounded like it was going to be very complicated.

now I am considering getting maybe 6 jars and putting silver on copper in one, silver on brass in another and so on, those that work I will use, those I get problems with I will ask about and maybe I can add a little to the questions here that others can ponder and so increase the total knowledge.

it seems very little current is needed and I have many 24 volt din rail supplies of an amp or more, A psu could even run several cells if only a few milliamps is needed

I will try to keep notes of anything I think others may want to know.

maybe the silver will be good 'as is' after filtering with a buchner funnel and washing, maybe I should check for and dissolve out remaining copper or go further by using nitric and cementing out on copper though that will come much later I think

once again
many thanks to Mod the world and solar and all the rest, newbie or expert who helped.
 
Start with one item. Hammer it flat, if it isn't flat already. The ampere is low, because pure water has high resistance. Small distance and higher voltage (24V) give more ampere. The higher ampere you get, the faster the cell works (ampere = electrons or ions per time). But you are right, in this setup it will stay low.
 
first items are some blocks of copper from 1000A fuses
at a guess they are about 35mm square and 6mm thick with heavy silver on one face, will weigh them and suspend 2 of them in a 1.5 l jar about 100mm diameter inside and will add about 0.75l of tap water

items for the second jar are silver on brass cutlery, a lot of the silver is worn away but will see if the rest can be removed by the water.
will report back when done
 
Photo0223.jpgwell I did it...

I set up 1 jar with 2 old and worn out silver plated knives, total weight 125g
silver on brass and plenty of brass showing on these, I ended up getting 1 litre jars and as soon as I connected up a 12v supply the liquid went milky with streams of white going from the + side to the -, the minus was bubbling, after a few minutes there was about 8mm depth of a milky substance on the bottom.
stirred it up a bit and had it running for about 30 minutes then turned it off for the night.
will see what it is like tomorrow and will put it on again.

may set up a second jar tomorrow if I get time
 
shorthair801 said:
Awesome thread noticed the last post was from August is anyone still running this process?
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It has become my favorite for silver plated material. I would not use any other process anymore.
 
Gathering the stuff to give this a try, read the entire post and watched all your video. thank you for sharing this.

I have a 24v 8A dc battery charger that I am going to try first since it is laying in my do something in the future with pile of junk. Unless someone has tried this and has not had as results from it. I think I read that some was using 24v dc and it was going faster.


I do have a couple of questions 1. Do the cathode and anode need to be similar in size?

2. How big of container has been used? I am thinking of plated serving ware which I could cut up if I had too.

3. Has anyone tried it with silver plated on steel?

Thanks again this will be great for me if it works, I have been selling all my silver plate to the local yard for brass price. Which I will still get to do as well as keep the silver. The local PM refiner pays far less for silver plate than the scrap yard pays for the brass/copper in it.
 
I think the cathode chould be at least as large as the anode to have an optimal rate. The shorter the distance of anode and cathode is, the more amps you will gain. Ampere means electrons or ions pathing through per time. More amps, faster stripping. Be carefull with the electricity. Also low voltage can harm you, if enough ampere find their way into and through your body.

I think you would be more happy with this method, if you first learn more about cells and electrolysis and start with small setups to become familar with it.
 

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