An other silver cell problem

[esucll]

Hello gentlemen. I have read several post regarding silver cell but i havent got a solution yet to my problem.
I have about 10kg of silver shot i want to run through my silver cell.

My cell is a stainless bowl with 4liters capacity. The first time i run it at 3.5Volts with 2.2 amps drawn and 150gr per liter electrolyte. I got very fragile needle like crystals.
I am now running my cell a second time at 1volt , 0.3 amps and i get the same needle like crystals.. Any one knows how to remedy this problem?

the photos attached is by running the cell for only 10 hours

Thanks you all in advance

 

[Yggdrasil]

Hello gentlemen. I have read several post regarding silver cell but i havent got a solution yet to my problem.
I have about 10kg of silver shot i want to run through my silver cell.

My cell is a stainless bowl with 4liters capacity. The first time i run it at 3.5Volts with 2.2 amps drawn and 150gr per liter electrolyte. I got very fragile needle like crystals.
I am now running my cell a second time at 1volt , 0.3 amps and i get the same needle like crystals.. Any one knows how to remedy this problem?

the photos attached is by running the cell for only 10 hours

Thanks you all in advance

I'm not a guru on Silver cells, but it seems you have quite a heating on the Anode.
The insulation on the cable seems to have peeled back due to heat.
You need to assure proper contact to the Anode and the Cathode.
Also I think most run it with higher electrolyte loading.

 

[esucll]

I'm not a guru on Silver cells, but it seems you have quite a heating on the Anode.
The insulation on the cable seems to have peeled back due to heat.
You need to assure proper contact to the Anode and the Cathode.
Also I think most run it with higher electrolyte loading.

Thanks for the reply
The insulation on the wire of the anode melted when i poured the molten silver on the copper wire to make the anode, i stripped it like that.

Will try your suggestion and try a more concentrated solution the next time.

 

[Martijn]

Welcome to the forum.
The anode/cathode surface ratio may be too small.
Try a bigger basket or a smaller bowl.
How is the anode basket made? Holes in a cup or a free hanging filter cloth? It may limit the flow of silver nitrate as well.

 

[esucll]

Welcome to the forum.
The anode/cathode surface ratio may be too small.
Try a bigger basket or a smaller bowl.
How is the anode basket made? Holes in a cup or a free hanging filter cloth? It may limit the flow of silver nitrate as well.

Thanks for the welcome

The anode is a cup with holes and a filter cloth. I followed your instructions just now. I changed my cathode bowl to a smaller bowl and made some bigger holes on my anode cup. The cell now runs at 1.5V and 0.95 amps.
Attached is a photo of my second failed cell run. The crystals came paper thin

 

[lanfear]

Your electrolyte seems like pretty pure Ag nitrate. I thougt it was suposed to be some Cu contamination in it.

 

[esucll]

Thanks for your answers. I will try an other design of a cell, as i understood, this type of cell is not suitable for making large enough crystals, the cathode is indeed too big

 

[Argentum Auricle]

I use a very similar setup. Where I deviate from everyone else is the wattage going into the cell. Higher wattage (v * w), the higher the rate of electro-deposition, the thinner/wiry your crystals will grow. Lower wattage means a slower rate of deposition, but the crystals grown in this manner are thick and chunky.

I run my 3L cell at about 1v/0.6 amps. It takes about a three weeks to run 40 ounces through one run (I do at least two rounds in the cell for each batch to get .99999+.

One last thing, which was already brought up by Lanfear. Pure AGNO3 electrolyte will not produce thick, chunky crystals. You need a certain amount of contamination (from copper, in this case), to get really good crystals. Until you get a decent load of trace copper in your electrolyte, you may keep getting the same results.

 

[Argentum Auricle]

I use a very similar setup. Where I deviate from everyone else is the wattage going into the cell. Higher wattage (v * w), the higher the rate of electro-deposition, the thinner/wiry your crystals will grow. Lower wattage means a slower rate of deposition, but the crystals grown in this manner are thick and chunky.

I run my 3L cell at about 1v/0.6 amps. It takes about a three weeks to run 40 ounces through one run (I do at least two rounds in the cell for each batch to get .99999+.

One last thing, which was already brought up by Lanfear. Pure AGNO3 electrolyte will not produce thick, chunky crystals. You need a certain amount of contamination (from copper, in this case), to get really good crystals. Until you get a decent load of trace copper in your electrolyte, you may keep getting the same results.

Also... I don't like to use a stainless steel bowl for my cell. Instead, I use stainless steel collanders, so that when the cathode is full of freshly grown crystals, all I have to do is remove the collander and put another one in, and my cell is ready to keep producing crystals, with no down-time.

 

[Argentum Auricle]

Thanks for your answers. I will try an other design of a cell, as i understood, this type of cell is not suitable for making large enough crystals, the cathode is indeed too big

Hello,ecucll!

Yes, indeed. The surface area of the cathode is a big factor in how silver deposition occurs. For instance, there is a direct relationship between cathode size and amperage. More surface area requires higher amperage; less requires correspondingly lower amperage - per square inch of cathode surface area. Likewise, the size of the anode basket plays a similar role. Making the surface area of the cathode smaller, while increasing the size or efficiency of the anode would improve the efficiency of the cell, overall. If not using a hanging bag for your anode basket, make sure you have a ridiculous amount of holes in the cup being used, to ensure that the flow of AgNO3 out of the anode container can keep up with the draw from the cathode.

 

[esucll]

Changed my setup.
I am now using a 2 L stainless bowl and the next day made an other cell using a 2 L beaker. I am running both to compare results.

Things look promising. I will post photos when i am done. Anode vs Cathode size, distance between them and amperage were the key factors into producing better crystals

Thanks for your tips

 

[bencrazy_metals]

Also... I don't like to use a stainless steel bowl for my cell. Instead, I use stainless steel collanders, so that when the cathode is full of freshly grown crystals, all I have to do is remove the collander and put another one in, and my cell is ready to keep producing crystals, with no down-time.

Man, that is a great idea !

 

[bencrazy_metals]

Man, that is a great idea !

Have you ran into any problems using the colander technique? I am thinking about stopping my cell right now and putting one in it tonight. Are you still using a stainless bowl to contain your electrolyte ?

 

[Argentum Auricle]

Have you ran into any problems using the colander technique? I am thinking about stopping my cell right now and putting one in it tonight. Are you still using a stainless bowl to contain your electrolyte ?

Hi, Ben.

I still use stainless steel colanders, with no issues. I have a dual setup with two separate 5A/30v power supplies so that I can run two 50 ozt cells simultaneously (each colander holds about 50 ozt before the crystals become too large/heavy, and start detatching from the cathode wall. My operation is on the smaller side - 3L non-magnetic stainless steel colanders inside 4L PTFE bowls.

Cheers!
-Mike T.

 

[Argentum Auricle]

Here's one right before a colander change.

 

[Argentum Auricle]

Finished .9999+ Ag crystals.

 

[Argentum Auricle]

Nice little chunky crystal with a mirror finish.

 

[BLACKESTFOOT]

Here's one right before a colander change.

How are you connecting power to the colander?

 

[BGDOCK]

I use a very similar setup. Where I deviate from everyone else is the wattage going into the cell. Higher wattage (v * w), the higher the rate of electro-deposition, the thinner/wiry your crystals will grow. Lower wattage means a slower rate of deposition, but the crystals grown in this manner are thick and chunky.

I run my 3L cell at about 1v/0.6 amps. It takes about a three weeks to run 40 ounces through one run (I do at least two rounds in the cell for each batch to get .99999+.

One last thing, which was already brought up by Lanfear. Pure AGNO3 electrolyte will not produce thick, chunky crystals. You need a certain amount of contamination (from copper, in this case), to get really good crystals. Until you get a decent load of trace copper in your electrolyte, you may keep getting the same results.

Watts = volts x Amps

 

[Argentum Auricle]

Watts = volts x Amps

You are right! Thanks for the correction. I meant to say Watts = v * A. Such an elementary mistake!