a reformatting of most of the Haver, Bixby, and Wong report about #lead chloride #materials #electrolysis and #hydrometallurgy
on 02023-06-17Haver, Bixby, and Wong published Bureau of Mines Report of Investigations 8276, “Aqueous #Electrolysis of #Lead Chloride”, in 01978, as part of the US Department of the Interior. They leached galena with aqueous FeCl₃ and NaCl at 100° to get #materials solid #sulfur and lead chloride (which is reasonably water-soluble at this temperature). They were able to reduce the PbCl₂ to metallic lead through electrolysis, either in molten salts (which requires less energy) or in aqueous solution. “Optimum results [for the #hydrometallurgy process] (96-pct current efficiency, 0.23 kwhr[sic]/lb Pb) were obtained with 20 pct HCl at 25° C, using a current density of 15 amp/ft² and an electrode spacing of one inch.” They also got reasonable efficiency at up to 20× higher current densities. Apparently the NaCl functions as a catalyst. They purified the “pregnant solution” by passing it over lead shot before cooling to remove silver, copper, and antimony. If they did the electrolysis in the “spent” leach solution, the FeCl₂ in it would reabsorb the chlorine thus produced and become FeCl₃. They used a graphite anode and a lead cathode at the bottom of the electrolysis cell. For the molten-salt process they centrifuged out the PbCl₂ and reabsorbed gaseous Cl₂ into the stripped spent leach solution in an absorption tower for recycling back into the leach tank.
on 02023-06-17