Electrorefining Missouri Low-Antimony Lead Bullion

摘要

The report describes a Bureau of Mines investigation of an electrolytic procedure for refining Missouri lead bullion. The procedure is more energy efficient and environmentally acceptable than conventional pyroprocessing. By adding 1 pct Sb to the lead bullion anodes for stabilizing anode slimes during electrolysis, or using anode bags to collect loose slimes formed on anodes without added Sb, the resulting electrorefined products analyzed 99,999 and 99.99 pct Pb, respectively. Energy consumption was low--70 to 90 kwhr per metric ton of refined lead, and the current efficiency was near 100 pct. Electrorefining was conducted in laboratory cells containing lead fluosilicate electrolyte with aloes and calcium lignin sulfonate as additives. A current density of 170 A/sq m and a cell temperature of 40C was determined to be most advantageous during 24- and 72-hour tests.