Stainless Steel Silver Cell

[Sputins]

Okay so let’s “image” these Silver Crystals even further!

I know someone who knows someone with access to a million dollar “Scanning Electron Microscope”.

So I asked my someone and they sent the crystals in to the SEM team. The SEM people loved the Silver Crystals and took glee in checking them out. These are some preliminary pictures of the actual crystals as seen in the beaker from the previous post.

Starting out at 1mm scale and going through and down to 5um, four scales in the series of pictures.

Each scale has two images, the ETD which is the standard electron scan and the BSTD which is called the back-scatter scan. With the silver crystal, it shows different contrasts.

1mm ETD
1mm BSTD
500uM ETD
500um BSED
30um ETD
30um BSTD
5um ETD
5um BSTD

These scans were an initial 5 minute play and I’m told they’ll take have another more detailed in depth look at them.

 

[g_axelsson]

I love it!

I know some people who knows a guy with a SEM too... rather everyone I know knows a guy with a SEM he got for a pittance, me! :mrgreen:
This makes me long to dig out my SEM and get it running again, but it has to wait at least until this autumn. I bought it for $750 and it was in running condition, but I have never had time and space to get it running yet.

Göran

 

[scrappappy]

I'm not Superman but that's a nice Fortress of Solitude 8)

 

[Lightspeed]

Aplogies for resurrecting a very old thread.

I have started a cell as per Kadriver and Palladium, I have a few queries on my setup.

My electrolyte is from cemented shot, silver concentration is 540g into 3L total electrolyte= 180gm P/L. The electrolyte after shot digestion had a slight tint of yellow.

The stainless cathode is indeed 3oo series non magnetic capacity of 3.5L.

There are 3 cathode connections spaced evenly around the circumference.

I have run initially at around 3 amps current giving around 2.3/2.6 volts, after 12 hrs of running this has been increased to 4.7 to max 5 amps to give 3.4 volts. After 30hrs due to electrolyte level increase from silver growth, the cell was shutdown for clean out and re started.

After harvesting the cell I noted there was a large quantity of fine crystal, when compared with Ralph's and Kevin's who both seem to be growing much more dense, this was evident around the edge surface of the bowl while at the bottom underneath the anode the was a much more dense crystal structure and some very nice chunky crystals which needed to be knocked down just to be safe from short although a fuse inline is fitted.

After re start without change to the silver concentration of the electrolyte the cell is reading 4.3 Amps at 3.1 volts.

Can someone offer advice as to the current flow and voltage relative to crystal growth density?
Is running higher amps a possible source of fine crystal growth?
Does running at lower than 3 volts have an effect on co deposition?

The top pic was taken after approx. 18 hrs run, the electrolyte is still in place I removed the anode and cover to knock down some of the crystal under the anode area for safety.
The bottom on cleanout after approx. 30hrs this morning.

 

[Palladium]

Crystal growth and density are controlled by about 10 different variables and change like the weather from batch to batch. Compact crystals usually form from high current, low voltage, and high concentration (Grams per liter) solutions. High voltage, low amperage, weak concentration solutions produce stringy crystal growth. You're experiencing low current densities when you get further and further away from the anode towards the cathode. Around the rim of the bowl at the top is further away that directly under the anode so the phenomena is more pronounced there. When you first start your cell the contaminants are low so you can actually run about 5 volts and see where the current falls. As you deplete the solution bring the voltage down to around 3 volts to help with co deposits. Other things that can and will cause stringy growth is anode surface area in relation to cathode area, restrictions in your filter cloth, and the type or amount of contaminants in your solution. All these things can be a juggling act!

Just for producing pure marketable silver your looks good!

 

[Palladium]

Tell us about the source materials? Are you using shot in the basket or bars? What is your filter material?

 

[Lightspeed]

Ralph,
Source material is Australian pre decimal scrap, mostly pre 1946 .925 coins. There has been a small quantity of post 1946 pre decimal scrap which is .500, also sterling scrap from jewellery, jewellers scrap also sterling flatware, old trophies etc.

The raw material has been HNO3 digested and cemented from copper, a small amount was through Sodium hydroxide process due to a chloride contamination early on in my HNO3 digestion efforts from contaminated glassware I think.

The cement has been reduced to shot by myself and is introduced to the anode basket, I have been using the Dacron wet vac bags as per Kadriver, but these are very expensive for me to get hold of here in Australia and are ex U.S.A.

All info has been derived as per my study the forum resource and from your own vids Ralph and Kadriver youtube vids which was inspiration and my resource until I found you both stashed here on the forum. Much further study from there on but the stainless cell as exemplified has been derived from your success Palladium.

 

[g_axelsson]

Nice crystals! I like the ones where you could really see the crystal structure and flat surfaces.

Yellow tinge to the electrolyte might be a result of a slight palladium contamination. It would follow silver through dissolving and cementing. You could clean that up with DMG if it becomes a problem. Here are two threads on that problem.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=18929
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=19004

Göran

 

[Lightspeed]

just did a quick test on the electrolyte with stannous, got a yellow tint that changed to brownish. I need to make a new batch of stannous.

You are correct Ralph and Goran, I am familiar with early silver pieces carrying gold and pgm's but had not thought of testing with stannous, I forgot I even had it :roll:

Although the electrolyte has been watered down I will make a new batch of stannous and re test, thanks for the tip on DMG I have read here on the forum that the PGM's are easily removed with it after HNO3 digestion. I have not noted slimes in the anode bag at this point but am less than 1 kilo into the shot at this stage. Thanks for the tip. 8)

 

[Palladium]

Yellow tinge to the electrolyte might be a result of a slight palladium contamination. It would follow silver through dissolving and cementing.

Göran

Yep! That's what i was thinking. That's why i was wondering about the source.

 

[Palladium]

Two of my youtube cell video's are private. Have you watched all 5?

 

[Lightspeed]

I am not a subscriber to your channel Ralph, do I need to be to see the others? I have seen every vid you have produced relative to silver that I have access to whether applicable to my intended procedure or not eg formate process etc. How do I access your private material? I would be very interested to further improve and cross reference to what I am doing at the moment. I also have the set of Lazersteves DVDs, I mostly have used them as a visual supplement for reinforcement of my existing knowledge but sadly does not cover the stainless cell. I do have a fair stack of Karat Au alloy and am kitted out for it, I will one day find the time to start on, for the time being Ag is my start point as the mistakes are more financially forgiving, and I would like to refine my process to reliability however I do find silver rewarding but at the same time complex due to the many stages involved, I have read many find Au much simpler. Regards B.

 

[Palladium]

.

 

[g_axelsson]

I just have two comments... :wink:

Anyone that think they can refine without using gloves and not getting something onto you should work with silver for a while. It's revealing.

That was a really green electrolyte, looks like quite a bit of palladium dissolved in it. Pure copper and silver nitrate is a clear blue color without any hints of green in it.

Thanks for sharing. Don't think I have seen them before. I had to skip some parts so I might have missed something you said.I heard the mentioning of your reason to not use gloves, but I didn't hear anything about palladium contamination of the electrolyte. It's easy to test the finished silver for contamination, just dissolve it and look for any color. Copper blue, palladium yellow, and the dissolved silver could easily go into the next batch of electrolyte.

Göran

 

[Lightspeed]

Just made a fresh batch of stannous, tested the electrolyte again with a brown indicator for palladium. After harvesting the cell and restarting, I have kept current at 4.7 amps and 3 volts, I don't know exactly why but this second run has the crystal sticking to the sides of the cathode without tumbling down the sides to the bottom, I think this was due to the cathode being new making it more difficult for the crystal to stick under its own weight due to the polished surface. Just need to tackle my palladium issue now. Thanks so much for the replies, I am sure it is rather simple to the experienced, your wisdom and tips are invaluable, cheers Ralph for the link, I am going to try and find a cheaper resource for a filter. Regards B.

 

[Palladium]

Muslin cloth is dirt cheap!

 

[snoman701]

The actual filter bars cost $2.57 ea from anode products. High enough quality bags that I'd use them to store coins in.


Sent from my iPhone using Tapatalk

 

[muhamed]

I have question about silver cell. How much I get on the cathode if the anode is 300g 999 silver and 250g / l in the electrolyte

 

[Palladium]

Theoretically if the anode dissolves 300 grams of .999 silver then the cathode will deposit the same.

Here's some interesting reading for those who like research. :arrow:

 

[kurtak]

Hi Palladium

Very interesting read & your timing on posting it could not be better as I am now going to have to re-think my current plans

I see that this article relates more to a "winning" cell rather then a parting cell which results in the production of ammonia from a nitrate solution during the course of winning the metal back out of the nitrate solution

I just finished my first set up/running of my silver cell sense my recent move from Wisconsin to Oregon

Today I intend to cement the silver back out of the electrolyte which of course will live me with a copper nitrate solution

Because of my recent move I no longer have access to cheap nitric which leaves me with a limited supply of nitric that I brought with me (something like about 12 gallons)

Soooo - I was planning on setting up a winning cell with the intent to win the copper out of the copper nitrate with the thought being that I could recover my nitric for re-use (instead of cementing the copper with iron & then dropping the iron with NaOH)

However (if I understand the article right) running the copper nitrate in a winning cell will actually cause the production of ammonia which is not a desired result

so it looks like its back to cementing the copper out with iron

Kurt