Rsr Limited

Herschel B McDonald

Raymond D Prengaman

An improved insoluble anode for electrowinning is described which comprises a graphite substrate covered by a tight fitting sheet of a nonconductive electrolytically inert mesh material over which covered substrate is electrodeposited a layer of lead dioxide. The anode is formed by covering the graphite substrate with a sheet of the inert mesh material and thereafter electrodepositing lead dioxide thereon until a smooth layer of lead dioxide completely covers the mesh material. The anodes are electrolytically stable and are not susceptible to cracking.

Stable lead dioxide anode and method for production

An electrolyte and a process for reducing lead peroxide formation when electrowinning lead from inorganic acid solutions are disclosed. In accordance with the invention, arsenic is added to an inorganic acid electrolyte containing lead, whereby oxygen is evolved at the anode while lead peroxide formation is reduced or eliminated during electrolysis.

Process for reducing lead peroxide formation during lead electrowinning

A process for recovery of substantially all lead values in battery sludge as metallic lead is disclosed. By means of the process, lead is substantially completely and efficiently recovered as metallic lead in an environmentally acceptable manner. The process comprises (a) subjecting the sludge to low temperature reducing conditions; (b) converting lead sulfates to insoluble nonsulfur containing compounds while solubilizing all sulfur materials and thereafter separating the solid residue by solid-liquid separation techniques; (c) dissolving the solid products resulting from steps (a) and (b) in an acid selected from the group consisting of fluoboric and fluosilicic acid; (d) collecting the supernatant from step (c) by means of solid-liquid separation techniques; and (e) electrowinning the lead from the collected supernatant. The lead peroxide reduction of step (a) may be effected by low temperature reducing roasts or by contacting the lead peroxide with sulfur dioxide gas or sulfites.

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Red Oak, TX, United States of America

Herschel B McDonald