We humble earthlings are governed by some basic laws of physics. One particularly stingy law is the law of conservation of mass. That simply says that mass is neither created or destroyed in a chemical reaction. That means if you put in a pound of sterling silver into a silver cell, all you can expect out of the cell is 92.5% of the pound as pure Silver. The 7.5% is copper and will not come out of the cell with your pure Silver.
The profit in starting a silver cell can be realized by purchasing impure Silver under spot price and selling the refined Silver for more than you paid for it. If you do gold refining by inquartation as sreetips often does, there is an excess of cement Silver that he accumulates. Seeing that he is not infinitely wealthy (at least I think not) he has to recover that Silver and refine it to sell to recoup his expenses. A Silver cell allows any other valuable metals to accumulate in a way they too can be recovered, refined, and sold as well.
Often Silver is refined because there is a need for higher purity Silver in a process. For example I have taught many assayers how to set up small Silver cells because a fire assay uses high purity gold free silver to determine the gold in an alloy or scrap bar. To buy that high purity certified Silver is not inexpensive. Since the silver is always recycled, never lost, there comes a time where making your own high purity Silver in house is cost effective. (not to mention fun.......sorry that's the nerd in me talking!)
You will have to determine why you need to set up a Silver cell for your own purposes. Every refiner or hobby refiners goals are different. Enjoy the journey!
