I don't recall the dimensions, but they are not critical. The only pertinent considerations are the anode size and anode/cathode spacing. Even spacing isn't critical, as you'll overcome pretty much any issues (unless you don't have enough spacing) by varying voltage. If memory serves, the target voltage is what it takes to achieve 25 amps/square foot of anode. I chose to operate lower (about 15 amps/square foot), which provided a longer interval between times knocking down the crystals. I ran my cell steady, 24 hours, until I had processed all silver at the ready. I often ran it for a couple months steady.
You'd be best served to procure a copy of the book written by Butts & Coxe, which discusses silver cells and silver processing extensively. I do not recall the title, but do a search and it will be obvious.
Food for thought. The typical electrolyte consists of some copper in solution. I chose to use none, as it was introduced fast enough simply by running the cell, as silver recovered by cementation with copper will always contain traces of copper.
You may read that the lack of copper alters the deposit, which is true---but the reports made by at least of those who didn't use copper free electrolyte are not correct. I parted tens of thousands of ounces of silver, always starting with pure silver electrolyte. My reason was simple. I got more silver from each lot processed, because the amount of copper in solution is what limits the useful life of electrolyte. The net result (ALWAYS) of not including copper at the outset was a film of solidly adhering silver--not crystals. That was followed by the formation of dense crystals, as the copper content rose. When content was high enough, the crystals, which had previously been rigidly fastened to the cell, now were very easy to remove. Continued operation caused a further rise in copper content, at which time the deposited silver began growing as thin threads. This reaction was characteristic of all my runs, so I had to conclude that copper aids in the stripping of crystals, but should not be allowed to accumulate beyond reasonable limits, as once it's too high, copper co-deposits with the silver, just as palladium will if it accumulates in the system. Armed with this thought, the moment thin threads started forming, I cleaned out the cell and replaced the electrolyte. I also started with a new anode, which was simply placed on top of what remained of the previous anode. As a measure of purity, I'd use the last silver harvested to make the next electrolyte. If it was free of blue coloration, I knew the silver was not contaminated with copper.
I recommend no less than 2" clearance from the anode surface to any surfaces of the cathode. The more you provide, the longer the cell can operate without attention. It is very important that crystals not be allowed to grow near the anode basket, as the resulting arcing will perforate the filter and contaminate the already processed silver.
What I recommend, if you're interested in parting silver, is to study until you understand the principles involved, then make a setup and pursue the operation of the cell. Consider your first run a learning experience, and that you may make mistakes. It's easy enough to re-process the resulting silver, which can be as simple as placing the harvested crystals back in the anode basket, even without melting.
Harold
