Designing a DIY silver cell

[4metals]

On another thread about refiners in Europe, posts between myself and Shark lead to questions about making a reasonably productive Silver cell and how to build it to simplify harvesting the crystals. I found on line a steeply sloped bottom tank called an inductor tank from Tank Depot 60 Gallon Inductor Tank 62205 | Tank Depot that will allow a 4" drain line for crystals to drop. At 30" in diameter it should be relatively easy to cut the top and add anode buss bars and cathode bars and a cathode rocker to a 21" square cut into the top. After doing some math and configuring just what would fit in that space to determine the size and quantity of cathode plates, I realized that we could make a system with 3 anode buss bars to hang anodes in anode bag baskets and 4 cathodes and make a system to run from a 250 amp rectifier that could produce up to 630 oz in a 24 hour day.

Then I thought, "how many of our members would actually be interested in a cell that large?" So I slowed my thought process down a bit and figured what may really be needed is something to go in-between the stainless bowl cells and the smallest of the commercially manufactured cells.

Bottom line is, before we start designing, (which would be a good community project to take up), what is a realistic consensus of opinion as to how many ounces a week would a reasonable cell produce? Keeping in mind the size of the power supply needed and what a smaller refiner could feed the thing consistently.

So before we start designing something no-one is actually interested in making, just how big should this cell be. Answers in T.O. fine silver produced weekly.

What is the consensus?

 

[Lou]

Not a fan of the geometry of the tank but I sure would buy one if it came in a squared up version. I got rid of all my big cells about 5 years ago and every now and then I'm like, "crap! why did I get rid of these, again??"

Realistically, most people aren't going to setup to autonomously run, or go scrape/empty a 24/7 cell operation. So if you rated it at 315 ounces/day * 4 days a week (with one day being electrolyte make up, slimes recovery), you would be at a reasonable amount of silver produced...1200 ounces every week assuming what gets kicked out of the electrolyte goes back into it.

 

[4metals]

Not a fan of the geometry of the tank but I sure would buy one if it came in a squared up version.

I agree with a squared up version but the place those tanks fail is on the welds of the taper. Since this is a DIY effort, and most of us are not proficient PVC welders, that is why I went with rotationally molded.

 

[Shark]

For really small scale this design was one I have looked at for a while. Unsure of the plastic it is made from.

https://homebrewing.org/products/the-catalyst-fermentation-system
The following comein 3, 7.9 and 14 gallon but have really small openings for the drain end.

https://www.midwestsupplies.com/col...ducts/fast-ferment-conical-fermenter-3-gallon
Most these can be found cheaper on Amazon as well, here is a real budget one.

https://www.amazon.com/FastFerment-...ords=plastic+fermenter&qid=1661187759&sr=8-11
These would be nice, as anything designed to fit one should be easily scalable to fit the others. For me anything 50TOz and up is a huge jump, and 100TOz in my thinking is where it starts becoming small scale serious. But in range for many members who are actively working at growing.

The square tank, as Lou mentions would be a big plus and most plastics can be molded to some degree fairly easy, but is always a risk. On the 3 gallon tank I might try it where as the larger, more expensive ones I would seriously hesitate.

 

[4metals]

For me anything 50TOz and up is a huge jump, and 100TOz in my thinking is where it starts becoming small scale serious.

when you are talking in the range of 50 oz a week, I think the best option would be to scrape, or let a small cathode rocker scrape, and allow the silver to lay on the bottom of an off the shelf tank.
14 Gallon Polypropylene High Temperature Tamco® Tank - 12" L x 12" W x 24" Hgt. | U.S. Plastic Corp.

That's pricey but polypro will stand up the longest, PVC is better but this is just to show size.

 

[Shark]

I like the idea of the self cleaning cathodes. As much as a larger cell, having some self maintenance would be a time saver.

I am trying to picture the placement of the square catch tank. Would it just sit under the cell like a catch pan, or be attached in some way to the cell?

 

[4metals]

Whoops didn't mean to post that yet.

when you have processed for a week you could have a drain valve a few inches up the side to drain off the electrolyte, lift off the anode cathode configuration, which we make to place on top as a unit, and lift the tank to pour out the rest of the electrolyte and gather your crystals.

For example with a 5 amp rectifier and a 0.2sq foot anode you can deposit 13.5 oz per day and it could lay at the bottom until you process all of your anode material. (in theory)

I was hoping for visions of grandeur and, as Lou suggested in the 1200 oz aweek range (with Fridays and weekends off)

 

[Shark]

A larger cell would be great. I am mainly thinking of something scalable to fit a larger crowd. A while back I scaled the stainless bowl many use down to a half liter size for experimenting. It worked well enough, but I had more silver than I thought i did then.

 

[Shark]

when you have processed for a week you could have a drain valve a few inches up the side to drain off the electrolyte, lift off the anode cathode configuration, which we make to place on top as a unit, and lift the tank to pour out the rest of the electrolyte and gather your crystals.

Tilting furnace type stand?

Edit: now I am thinking bigger.

 

[Shark]

Quick glace through the Tank Depot web sight shows a variety of tank sizes, (should have known it would) and keeps the scalability idea in play.

Edited for spelling.

 

[Martijn]

I think for the most hobby refiners a small simple cell will be enough. You can run quite a bit if you take your time with a one liter cell.

 

[4metals]

In the early 1980’s I ran 18000 oz in a 10 gallon fish tank in my barn. So yes it can be done. But I thought a discussion concerning the design, and the why behind it, would be interesting for some members.

A full discussion would include copper build
up from processing sterling and analysis to keep the cell running by titrating the solution and adding nitric acid to maintain the silver nitrate level in the electrolyte.

Personally I already know how to do this stuff but if there is interest it’s worth doing. But if all members are looking for is a stainless bowl
Silver cell then who am I to argue.

 

[Shark]

I think for the most hobby refiners a small simple cell will be enough. You can run quite a bit if you take your time with a one liter cell.

True. I have also turned down silver because I knew I could not refine 50 to 100 pounds in 2 to 4 weeks. A bowl just wouldn't cut it.

 

[Shark]

In the early 1980’s I ran 18000 oz in a 10 gallon fish tank in my barn. So yes it can be done. But I thought a discussion concerning the design, and the why behind it, would be interesting for some members.

A full discussion would include copper build
up from processing sterling and analysis to keep the cell running by titrating the solution and adding nitric acid to maintain the silver nitrate level in the electrolyte.

Personally I already know how to do this stuff but if there is interest it’s worth doing. But if all members are looking for is a stainless bowl
Silver cell then who am I to argue.

The entire process start to finish is what interests me. Have a solid idea before needing it, is jump start in growing.

 

[Shark]

Here is one that might work for Lou. Still has potential to run in the volume range he needed and maybe into the first thoughts 4metals had as swell. I am not sharp enough to figure in my head the volume needed to produce in TOz.

https://www.plastic-mart.com/product/2789/56-gallon-total-drain-rectangle-tank-sp0056-rt
Edit to add:
For those needing something a bit smaller.

https://gototanks.com/shop-by-category/cone-bottom-tanks/cone-bottom-rinse-tanks.html

 

[4metals]

It’s all about the surface area of the cathode. The tank size has to be able to house the size of the cathode. Commercial systems run at 25-50 amps per square foot. And each amp will deposit 3.5 grams of silver an hour. So the size of the rectifier determines the rate you make silver. And the number of amps you can deliver determines the size of the cathode to stay in the 25-50 ASF range. The volume of the electrolyte is just like the volume of a goldfish bowl, the smaller the bowl the harder it is to keep it in balance.

 

[Shark]

Math test.

A six square foot cathode, running at 50ASF. Total of 300 amps. Possibly produces 33+ ounces of silver per hour. Or over 810+ ounces in 24 hours of continuous runtime.

That I would love to see happening!

 

[orvi]

Maybe bit late to the discussion, but I agree - this is a very good idea, wheather it only end up in discussion, or collective brainstorming with end result - checked by professionals
For me, the best idea would be design that is convenient to use on daily base, and automatic scraping may be the nice feature. Also we have professionals here with decades of experience, so any culprits can be detected in early stages as they certainly know more than others.

And also, I think it could be scalable by varying the dimensions of the apparatus to fit one needs.
Speaking by myself, I am certainly not capable to push even 1 kg silver a week. I know that many members here would welcome the design that will allow multiple kg/week. And some maybe few kg/day.
But these numbers aren´t that wildly distant in the means of setup - of course, dimensions of the tank/anodes/cathode/etc would be different, but the setup remains the same.

 

[markscomp]

Math test.

A six square foot cathode, running at 50ASF. Total of 300 amps. Possibly produces 33+ ounces of silver per hour. Or over 810+ ounces in 24 hours of continuous runtime.

That I would love to see happening!

not average for home / small bus refiner [- the 300 amps }

use 37.5 amps times 3.59 is 134.65 gm silver

lets say gram of silver at 16 divided by 31.1 rough in at .5$ thats Point 5 - (lower than today but roughly average over years and easy divide (able) per gram) so 67$ +/- so you are creating

so with purchase, cost of electricity per hour or amp hour, maintenance, lots of labor, chemicals and a profit

little bit of long term funds to go out toward building purchase, taxes etc.........

 

[Shark]

How did you get to the 37.5amps and where does the 3.59 come from. I can see where your going with this, I am just missing something somewhere.