Stainless Steel Silver Cell _smallsilvercell_

[g_axelsson]

If you read the article it seems like one of the key parts in nitrate reduction by electrolysis into ammonia is that it occurs on a silver surface. In the paper it says that they were unable to get any ammonia production when they were using stainless steel electrodes and that it probably was because the silver didn't form a smooth surface. Apparently the silver works in a catalytic way to form ammonia under certain conditions.

So it is plausible copper winning from a nitrate solution will produce nitric acid and not ammonia. Just check the pH and don't run the cell longer than necessary.

Göran

 

[kurtak]

Goran

Thanks for the reply & sorry for the delay in responding (been busy)

If you read the article it seems like one of the key parts in nitrate reduction by electrolysis into ammonia is that it occurs on a silver surface.

The real purpose of the paper was/is the concern of producing silver nitride during winning - silver nitride being an explosive compound of silver - also referred to as fulminating silver (which is different from silver fulminate - both of which are explosive)


The production of silver nitride is the result of the reduction of the nitrate to ammonia during the electrolysis when winning the (silver) metal from the electrolyte

In the paper it says that they were unable to get any ammonia production when they were using stainless steel electrodes and that it probably was because the silver didn't form a smooth surface.

I did read on page 16 of the paper where it talks about this - however - on page 31 (in the conclusion) when noting that reduction (of nitrate to ammonia) was not "observed" (in the experiments) on SS - it also makes note that - "the substrate is unimportant for observing nitrate reduction. The only requirement is that freshly deposited silver is required"

So I am a bit confused - & again the paper is more focused on the production of silver nitride as a result of ammonia production

Because I am looking at winning copper - instead of winning silver I still have concerns because on page 3 it talks about as high as 88% production of ammonia when copper electrodes are used

So - even if I used an SS electrode (as cathode) would not ammonia production take place once copper is formed on the cathode ? (basically turning the cathode to a copper electrode)

In other words I am not concerned about the production of silver nitride because I am not trying to win silver --- copper - to the best of my knowledge - does not form a (explosive) nitride --- its the production of ammonia when winning (copper) metal from a nitrate solution that I am concerned about


Maybe Lou, Deano, 4metals or some of the other real pros could chime in here about ammonia production as a result of trying to win metal from a nitrate electrolyte


Kurt

 

[Lightspeed]

Hi All,
has anyone tried running crystal through the anode basket instead of shot? If you have, have you had any issues with your amperage? Does anyone else warm the electrolyte before running their cell?

I was thinking the higher surface area of the crystal would lend an easy amp max to top out my power supply at 5 amps, not getting even close eg: 2.1A @ 2.4V after 12 hrs run, electrolyte saturation of 580g into 3 L, same set up as I usually use for shot, same anode basket, same cathode bowl, same filter material.
I do not like the crystal made from lower amp than voltage it is too fine and dendritic in appearance, there is something amiss and I just cant seem to delineate it, it is the first time I have re-run crystal. As the crystal is the only real change logic points to this, thus my question.

I have replaced all electrical connections from the power supply to the cell, new alligator clips, new inline fuse and holder, and yes my soldering skills are more than up to scratch. I have now removed the electrolyte back into a beaker and pyroceram and currently heating to see if this changes cell parameters when added back to the cell.
I am just about all out of ideas, short of stripping the cell and turning the crystal back to shot, it is a step I had hoped to avoid.

Suggestions?

Edit: replaced electrolyte after warming, now at 3.12A @ 2.4V, it is winter here in Australia though is around 18 Celsius.

For our Aussie silver refiners: I have been running around for ages going to all sorts of material shops looking for (AKA) Muslin cloth, got plenty of strange looks from the female staff basically telling me I did not know what I was talking about, well it turns out here in Australia Muslin cloth is basically an open weave gauze I have never found unbleached. So it turns out the folks in the mighty U.S. of A. and what is called muslin over there is actually called CALICO over here in OZ, its a dirt cheap unbleached material perfect for your anode bags.

 

[Palladium]

Can you post some pictures of the whole setup?

 

[nickvc]

One thought most advise to add some copper to the electrolyte to aid crystal formation so if you’re running pure silver with only fine silver in the electrolyte that may be some of your problem.

 

[Lightspeed]

As regards Copper in the electrolyte, after warming the electrolyte I decided to add a bout 500ml from a previous cell run which I keep for first run crystal, just to add a touch of copper, I am not a fan of this despite many resources saying to add it. I am only new to silver cells so what the hell do I know anyway. It seems counter intuitive to me after going to the lengths of keeping everything surrounding my silver refining overly clean. The electrolyte that I originally made for this batch was water clear from first run crystal.
Warming the electrolyte seemed to make all the difference, after checking the parameters again after work all is well as it should be with a healthy warm bowl of crystal. I will be keeping that in mind for future reference, electrolyte temperature is critical to cell function in cold temps using low cell amps.

A few quick pics as requested Ralph.
I know i am going to cop heaps of scrutiny over my setup, Its not super flash, my humble little cell, but I am constantly learning from its use. You will note the Teflon rod for stirring and pushing down the crystal in the basket, I am using some real cheap Perth Mint bullion rounds that I bought as scrap as anode starter bars for the time being. Polycarbonate top plate is not ideal but is functional and 8mm thick. Now that I know Muslin is actually Calico in Oz I will replace the filter soon, filter in place is Dacron. Note the mint green colour of the electrolyte from the small addition of copper contaminated electrolyte from first run crystal(this electrolyte is @ 146gm Ag per litre density). 3 cathode contacts fairly evenly spread.

 

[Palladium]

From what i can see i would guess your problem is anode surface area. You need more of the crystals below the surface of the liquid. As i'm looking at the pictures i can see that the crystals growing in the bowl make a line around the surface. Your crystals show that your liquid level is a good bit from the top. Your plexiglass is thick also. and if you look at your basket you'll notice that your filter cloth is curved at the bottom and only a small portion of the anode (crystals) are reaching further down into the solution. This tells me that when the basket is sit onto the platform that suspends it a very small portion of the materials are actually coming into contact with the solution. Fill your bowl up nearly to the rim. I know it makes handling it a pain to empty, but you can remove some of the solution to empty it by using a beaker to dip it out or decanting it with a hose. Besides it will evaporate down as the cell runs. Make sure your basket material is more flat to allow the crystals to set in the basket better. Use a thinner piece of plexiglass to cut down on the distance between the solution and the basket. Current density is causing your crystals to grow long and stringy instead of dense and compact. This is because of the anode surface area being relativity small in comparison to the cathode area. Not crystals, but when running shot this will lead to a lot of black powder in your basket. Some people get excited and think it is gold or pgm's. It's actually silver oxide. As the crystals grow on the cathode surface it gives the cathode surface many more times the area than just the flat surface of the bowl. This will lead to an increase in amperage and a reduction in voltage, if your anode surface can keep up with it. That is when your cell will really get to purring like a ***** cat!

I have 2 or 3 - 1 gallon cells ( 5 amp ) i play with out on the farm. In my unheated bld in the winter it averages in the 40's at day and mid to lower 20's sometimes at night. If your cell is operating at the right current density it will be making enough heat to keep the solution warm. I actually like the cold for my cells! Other than that your cell looks good and is set up right as far as i can tell. In a pure solution push that voltage up to about 5 volts in the beginning and let the current fall when it may ( usually around 3 amps ). As the crystals start to grow the voltage will start to fall and the current will rise. In my bowls on the farm by the time the bowl is about 3/4 of the way full my amperage is at 5 and my voltage is about 1.8.

 

[Lightspeed]

Thanks Palladium!!
I have on hand a few metres of American Muslin now to correct the anode contact area and rid the curved limited exposure brought about by too small sized filter to suit the basket. I have added electrolyte to bring up the contact area of the anode as well to within 15mm of bowl (cathode) fill limit.
I will rebate the polycarbonate sheet to give better depth and exposure of the anode.

As usual your observations are spot on Palladium. Thankyou for your critique to assist and correct where my experience plainly leaves me with nothing but trial and error.

Palladium: So due to lack of contaminants in the electrolyte and the feedstock anode I can push the voltage and easily hit max of 5A without worrying about co deposition in the crystal. It is logical, there really is not any other (copper) contamination source other than that which I have already introduced but maybe just me being cautious and conservative. Got a few things to work with now to get this cell "purrin". Thanks again for the pointers, I will report back when my icp spec assay is complete and a few bars are poured.

Kind regards
B.

a few pics of the cell since last nights pics.

 

[Palladium]

Yes! In the beginning your contaminate level is extremely low so no need to worry about the voltage being on the high side. The voltage will drop inline before your contaminate level rises to the point of disposition.

 

[Palladium]

:arrow: :arrow: :arrow: :arrow:

 

[Palladium]

I wonder what that cats up to now!
1 3/4 gallon!

 

[Palladium]

 

[Palladium]

 

[FrugalRefiner]

That's some interesting feedstock. Have you had it assayed? :lol:

Dave

 

[g_axelsson]

I thought we agreed on there is no profit in refining cats.

https://www.youtube.com/watch?v=K_zpdyBz3VM

Göran

 

[philddreamer]

Are you going to "incinerate" before you start processing it... :? :? :?

:mrgreen:
Phil

 

[Palladium]

He's the brains of the operation!
He's also the inventor of the M.E.O.W.S. process!

Multiphase
Electrolysis
Of
Waste
Silver !!!!!

 

[philddreamer]

Precious "cat" indeed!!! No need to process! :mrgreen: