# Improvement suggestions for my silver cell



## goldenchild (Aug 12, 2012)

I am partial to the AgCl method but I want to try a silver cell again. I'm using a 2 liter stainless steel container as the cathode and aluminum wire as the anode. I will use a non conductive item like a popsicle stick to hold up the anode basket attaching the positive current to the hanging wire and obviously the negative current directly to the vessel. I think I have everything covered but any constructive criticism is welcome. Thank you all in advance.


----------



## qst42know (Aug 12, 2012)

Can you cut that flask off at the shoulder so you don't need to work in the restriction?


----------



## element47.5 (Aug 12, 2012)

Cutting that stainless flask off would not be an easy task and would leave a sharp edge, probably with some distortions in it...unless you have the decent tools to work stainless, it is not for the faint of heart. 

For very cheap, you can go to a restaurant supply store and buy (under "steam table accessories") deep-drawn pans....for some reason I could not find round, cylindrical ones, but I have seen them and they are pretty cheap, like $10. You've seen them, too, like the deals restaurants serve salad dressing in at buffets. 






You can even buy a sheet of stainless steel with 2, 4, or 6 holes that match the lip of these types of pans. That would be fairly cool, no? You could have several cells going...and the master connection could be made to the support plate instead of the pans. Drop them in, they are connected. 

Slick setup, IMHO.


----------



## Geo (Aug 12, 2012)

it has to be better than 308 SS. the listing doesnt give the material of the pan. i would be sure to make certain of the material used. just because the number on the SS is higher does not make it better. some of the higher numbered SS will not work.


----------



## Harold_V (Aug 13, 2012)

Geo said:


> it has to be better than 308 SS. the listing doesnt give the material of the pan. i would be sure to make certain of the material used. just because the number on the SS is higher does not make it better. some of the higher numbered SS will not work.


I would expect the pans to be made of either 304 or 316, both of which will be more than satisfactory. 316 offers the greatest chemical resistance, but considering the electrolyte is a nitrate, that's not really much of a concern. 

Harold


----------



## Harold_V (Aug 13, 2012)

goldenchild said:


> I'm using a 2 liter stainless steel container as the cathode and aluminum wire as the anode.


I would encourage to to avoid using any element besides silver in the anode basket. That would be particulary true where it becomes part of the circuit submerged in the electrolyte. You would be far better served to cast a small piece of silver, to which you connect your lead, and then allow it to contact the top side of the anode. Don't allow the contact to become submerged. Keep the electrolyte level such that it touches only the bottom of the anode, so dissolution takes place progressively. That will help keep the anode uniform is size. Expect the edges to dissolve faster than the center, however. 



> I will use a non conductive item like a popsicle stick to hold up the anode basket attaching the positive current to the hanging wire and obviously the negative current directly to the vessel. I think I have everything covered but any constructive criticism is welcome.


I'm pleased to see you welcome input. 
Avoid using wood. It will surely become contaminated with silver nitrate and become conductive. I recommend you use some pieces of plastic (polyethylene) to suspend the basket. I also agree that the narrow neck of the flask you have shown is likely to be a lot more trouble than it will be good. At the worst, the container should be as large at the opening as the sides, so you won't struggle in removing the crystals. The square one shown would be an excellent choice. 

Harold


----------



## goldenchild (Aug 13, 2012)

So one of my main issues seems to be with the SS vessel. I actually thought about cutting the container to make it as wide of the bottom but as element47.5 indicated it is a task. I have the tools to do it but I see the cut being uneven and a sharp edge. I don’t want to make it an event just to have a vessel. This was a coffee carafe and I haven’t put anything but water in it so maybe I will just hang onto it. 



Harold_V said:


> I would encourage to to avoid using any element besides silver in the anode basket. That would be particularly true where it becomes part of the circuit submerged in the electrolyte.
> Harold



What specifically would be the downside to using aluminum wire? I understand what you mean by only suspending the anode as is done in LazerSteve's dvd but that always leaves pieces un processed. I wanted to go this route to get more of the anode processed. Using something plastic to hold up the basket is easy enough.


----------



## lazersteve (Aug 13, 2012)

Goldenchild,

I have made it a habit of never letting my positve connection lead reach the electrolyte as Harold points out. Just keep staking bars under the anode fragment with the connector. In the video I used a hook shaped connection, I have since changed this to a straight piece that I simply clip the positive lead to. Another change I made was to replace the supporting cross member with plastic hooks in each corner of the anode basket. 

Steve


----------



## Harold_V (Aug 13, 2012)

goldenchild said:


> Harold_V said:
> 
> 
> > I would encourage to to avoid using any element besides silver in the anode basket. That would be particularly true where it becomes part of the circuit submerged in the electrolyte.
> ...



While I never tried, I fully expect that aluminum will cement silver from a nitrate solution. I may be wrong. It most definitely will cement copper, and there's going to be copper present, whether by choice or the result of parting silver recovered with copper. 

While nitric doesn't dissolve aluminum, it does dissolve some of the elements that are constituents of many aluminum alloys. Beyond that, it isn't a good idea to introduce anything metallic, as it may or may not be transferred if it conducts, and your wire definitely will. I learned this lesson when there was minor bridging of my anode to one of the stainless screws which held my anode basket together. The head was slowly eroded, causing me to have to re-run that particular lot of silver. Do remember, under electrical influence, pretty much anything that conducts will erode. It reports in your silver under most circumstances. 



> I understand what you mean by only suspending the anode as is done in LazerSteve's dvd but that always leaves pieces un processed. I wanted to go this route to get more of the anode processed.


You are not thinking clearly. Your anode should lay in a horizontal posture, with one face exposed to the electrolyte. Contact should be made on the upper side, with NO TRACE of the attachment point exposed to the electrolyte. All of it will be digested, for all you have to do is add another on top of it as it shrinks. You recycle nothing but the very last trace of anode. You could part that, too, but efficiency falls off as area decreases. 

Do not "hang" your anodes. There's no good reason to do so unless you use alternate cathode plates. In your particular design, that isn't the case. 

Harold


----------



## Geo (Aug 14, 2012)

if i understand correctly, you would stack anode bars in the basket with the last one having the connection. as the bars below it are consumed, you lift the top bar and place more beneath it in a never ending stack. so the bar with the connection is a kind of failsafe to keep the connecting joint from coming into contact with the electrolyte.does that mean the last bar becomes part of the equipment? i suppose it can be thinner as long as you stay vigilant and not let the last bar make contact with the electrolyte.

could you use one of Steve's hardened graphite electrodes as the top block?


----------



## lazersteve (Aug 14, 2012)

Geo,

The graphits seems to decay more rapidly if it is connected to the positive lead. I prefer simply using a cast anode with a tab on to which I clip the positive connection.

Steve


----------



## Harold_V (Aug 15, 2012)

Because one is likely going to have to clean out the anode basket (slimes), stacking more than one anode at a time isn't exactly a good idea. The weight may be troublesome, in particular if the anodes are fairly large. Instead, one anode at a time should be parted, with the electrolyte kept just barely in touch with the bottom of the basket's filter. Any further exposure simply shrinks the sides of the anode, which isn't desirable. As the anode diminishes in size, and the area is considerably smaller, a second anode can be placed on top. There is nothing to be gained by stacking anodes. 

Cleaning out the slimes is quite important, in particular if one processes platinum group materials. They report in the silver, and build up considerably. I used to use an acid dipper to scoop out the slimes, which I did on a regular basis, lifting and tipping the anode to access the filter. If you part silver that lacks the platinum metals, you won't be troubled nearly as much, but even reasonably clean silver yields slimes, which are made up primarily of miniscule silver particles. 

Clipping directly to the anode isn't required. You are far better served to cast a button with a small shank, so the button becomes the connection point between the anode and the clip. Think of something like a 3/4" diameter head, perhaps ½" long, with a small diameter behind, to which you attach the clip. A silver nail with a thick head, for lack of a better description. 
This method of attaching allows for instantly removing the connection when removing slimes is required, by simply picking up the lead, to which the contact is fastened. 

By using this system, you never risk exposing the clip to the solution, and you have no concern about conductivity. If you follow this line of thinking, nothing is required to be re-melted and cast, as you can consume anodes fully, save for the very last one, but even it can be parted fully by sacrificing a little of the contact I recommend. If you intend to refine on a continuing basis, not just a one shot deal, the small remaining anode can be held over to be parted with the next batch, or it can even be re-melted if so desired. 

Harold


----------

