I was going to build an electrolytic cell to refine a bunch of pewter that I have laying around and was wondering if anyone had built a proper cell like this before or had any insights. I haven't really seen anyone refine large amounts before just very inefficient small-scale cells. I'm looking to refine about 50kg of what I believe to be lead free pewter. I think I want to build a cell with hydrochloric acid electrolyte and maintain a current density on the cathode of 0.2 - 0.4 Amps per square inch according to a study I read studying ideal current densities. I was wondering if anyone knows what I ideal voltage to hold the cell would be as I haven't seen any clear numbers and have seen voltages from 3-6v used. Also was wondering what an ideal cathode material would be. I have heard of people using stainless steel, titanium, and even seen people use paper clips in lab demos. All of these materials dissolve in hydrochloric acid though so I was wondering if it makes a big difference as to what I use or if being used as a cathode is just able to protect them from oxidation. Also, are there any issues with electrolyte fouling? I've read pewter mainly contains Bi, Sb, Cu as contaminates but also can contain Pb, Ag, and other trace metals. I will probably add a little sulfuric acid to the electrolyte to make sure if there is any lead it stays insoluble. Any other suggestions?