GB726536A - Improvements in or relating to the electrolytic production of lead - Google Patents

Abstract

726,536. Electrolytic production of lead. HALKYN DISTRICT UNITED MINES, Ltd., and NEWALL, A. P. Jan. 21, 1952, No. 1644/52. Class 41. Lead and sulphur are obtained from metalliferous materials containing lead sulphide, for example galena, by electrolysis of fused lead chloride containing such material, the concentration of lead sulphide in the electrolyte being maintained at a value below 1 per cent, preferably at 0.5 per cent. Alternatively the concentration of lead sulphide may be 0.5- 2.5 per cent when a chloride and/or sulphide of an alkaline earth metal is also present. Chlorine gas may be passed through the electrolyte to remove scum or to prevent its formation. The effective current density is maintained at 700- 1000 amps per square foot and the temperature of the electrolyte at 500-600‹ C. The cell employed may comprise a series of bipolar electrodes inclined forwardly in the direction of current flow, a voltage drop of 1.2-2.5 being maintained over each gap. The cell may be composed, or have a lining, of mineral talc, mineral steatite, fused silica or other material which is a non-conductor of electricity, has a negligible coefficient of expansion, is substantially non-porous and, in the conditions encountered chemically inert to the action of the fused electrolyte. Specifications 448,328 and 726,535 are referred to.