Stainless Steel Silver Cell _smallsilvercell_

[kadriver]

Today I am going to convert my silver cells from glass with graphite electrodes to a stainless steel bowl (6 inches deep and 8 inches across) with the entire bowl serving as the cathode.

I've got all the materials to make the cell and a nice 30 volt, 10 amp power supply to run it.

I am going to take some photos of the cell as I build it and post them later today.

Palladium claims that his "runs like a Ferrari" and that I will "throw rocks at the graphite cathodes" once I get the stainless bowl setup running - hope its true!

kadriver

 

[element47.5]

Looking forward to your usual excellent pix reports!

Are you planning to power the cell with the full 30 volts? Heat concerns? I guess we'll find out!

 

[philddreamer]

Element, he'll be using one of these; http://www.ebay.com/itm/30V-10A-10AMP-3010D-Pro-Digital-DC-Power-Supply-Precision-Variable-Adjustable-/330804337453?pt=LH_DefaultDomain_0&hash=item4d05799b2d

he'll be able to control the volts and amps, thus controling heating. I just got mine a couple of days ago! Palladium has one, too!
I'll be using mine for recovering copper from Cu-Cl and for silver refining.
I have a question in relation to the S.S. bowl for the silver cell, magnetic or non-magnetic?
Thanks!
Phil

 

[element47.5]

Excellent. Recall that kadriver has been using his PC power supplies so far and applying something like 3.3 VDC. Without current limiting, I would imagine (but do not know for sure) that 30 volts across a cell would draw a heck of a lot of current given the "fatness" of the current path through the cell. What the overall effect would be, I can't say with authority, but probably_not_so_good. Again, I am looking forward to kas' always neat pix!

 

[Palladium]

Non magnetic 300 series stainless.

 

[philddreamer]

Thanks, Ralph!

 

[Palladium]

Most of your restaurant equipment will be perfect. I have 5 gallon stainless pots and strainer spoons and you name it. Look for used restaurant supplies or walk trade day with a magnet.

 

[kadriver]

I'm not sure of the voltage - I think it was about 1.8 volts with the amps cranked up as far as it will go.

The bowl I have is nonmagnetic. It will take 3.5 liters to fill it to the proper level.

This will require 350 grams of pure silver (I'll probably use close to 400 grams in 3.5 liters of liquid).

I got it part way done today, then had to leave my shop.

I'll get it started tomorrow and post the pics.

kadriver

 

[kadriver]

Here is a shot of the bowl and its measurements.

I used an old cutting board and cut a hole in the top to allow a small tupperware container to fit into - this will be my filter basket.

Also drilled 1/8 inch holes and inserted bamboo skewers to align the basket dead center to keep it in place at all times.

 

[kadriver]

The bottom of the basket is 1.5 inches from the bottom of the cutting board.

The depth from the bottom of the basket to the bottom of the bowl is 4 inches.

 

[jmdlcar]

Is this the bowl you use?

http://www.webstaurantstore.com/3-qt-extra-heavyweight-stainless-steel-mixing-bowl-with-bottom-grip-non-slip-base/922MB03.html

 

[kadriver]

Next I poured off the used electrolyte from the old glass cells.





I re-used this electrolyte since it already had some copper in with the silver nitrate solution.

Goldsilverpro and Palladium both recommend adding some copper to improve crystal growth.

Palladium says that the copper makes the silver crystal easier to remove from the stainless bowl when harvesting the pure silver.

The used electrolyte needed to be filtered to get the dirt out - it was crystal clear after both filterings.



Plus I dissolved an additional 200 grams of pure silver in dilute nitric acid to bring the volume of electrolyte up to 3.5 liters (200 grams will give an excess of silver in the electrolyte).

 

[kadriver]

Next I transfered the filtered electrolyte into the stainless bowl.

I added distilled water to bring the electrolyte up to the proper level.

Then I transfered the anodes from the old glass cell filter baskets into the filter basket on the new stainless steel cell.

This basket was previously used in one of the glass cells, but still in good condition.

 

[kadriver]

I connected the powder supply, positive to the electrode in the anode basket, and negative to the rim of the stainless steel bowl.

I adjusted the voltage to 1.8 volts.

At this voltage, I could only get 0.6 amps to flow throught the cell.

 

[kadriver]

Close-up of the electrical connections

 

[Lou]

Perhaps consider making a bigger anode compartment?

 

[kadriver]

I bumped up the voltage to 2.8 volts with a corresponding increase to 1.1 amps current flow.

These numbers are the current operating parameters for now.

I am open to suggestions and critique as usual.

 

[kadriver]

I have a bigger basket, large enought to hold several 5 troy ounce bars.

I will try the larger basket next time around, thanks Lou.

Here is a shot of the inside of the cell after operating for an hour or so.

The basket is submerged in the electrolyte about 1/2 inch, I lifted the cutting board up to get the photo below.

Notice the silver crystal formation on the surface of the bowl.

This setup is much easier and less messy than the glass cells.

Plus, the disparity in parameters between the dual cell setup has vanished!

I can cut a larger hole in the other half of the cutting board and make larger anodes tomorrow.

Cheers!

kadriver

 

[Palladium]

How long has it been running at this point? Lou is correct from what i have learned to. Bigger anode surface.

 

[kadriver]

Palladium,

It had been running for about 3 hours at 1.8 volts and 0.6 amps when the photo was taken.

I adjusted it up to 2.8 volts 1.1 amps and it has been running like that for about two more hours now, time now 8:45 PM eastern.

I am going to the shop and check on it and get a new photo to see if the rate of crystal growth has increased since bumping up the voltage and current flow.

I am in love with this adjustable power supply.

What voltage would you recommend for this setup?

I can see where larger anodes are certainly needed to get the increased current flow that I am looking for.

Also, what kind of electrical shock hazard do I have here. I am going to get a rubber mat to place on the concrete floor to stand on when I am near the cell.

kadriver