Method of producing a lead dioxide coated cathode
AssigneeThe United States of America as represented by the Secretary of the Interior
InventorsLawrence L. Smith, Richard G. Sandberg, Ernest R. Cole, Jr.
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Abstract
A long-lived electrode is produced, for use in the electrowinning of metals, by electrodepositing a coating onto the electrode substrate. The coating has a uniform grain size and structure which is controlled by superimposing alternating current onto direct current during electrodeposition.
Claims4
A method for producing an electrode by the electrodeposition of a lead oxide coating upon a titanium electrode comprising immersing the titanium electrode and a cathode in an electrolyte solution containing nitric acid and lead ions in a concentration of about 180 to 210 grams per liter, establishing an electrical current by superimposing alternating current upon direct current to effect electrodeposition of said lead oxide wherein a uniform, dense grain size and structure of the electrodeposition coating is obtained by providing:
- (1) an electrode current density of from 0.03 to 0.08 amps per centimeter squared,
- (2) an electrolyte temperature of from 50.degree. to 80.degree. centrigrade,
- (3) a direct current voltage of from 1.4 to 5.0 volts,
- (4) a peak-to-peak alternating current voltage of from 1.6 to 7.2 volts,
- (5) an alternating current wave frequency of from 30 to 100 hertz.
Dependencies are inferred from the claim text.