Claims
- 1. A method of completely coating a plurality of substrates with lead dioxide by electrolysis while the substrates are immersed in an electrolyte containing a lead salt, each substrate having curved surfaces and being able to roll freely, comprising tumbling the substrates in a porous barrel rotating about a central anode feeder at a speed of three to eight revolutions per minute with substrates contacting the anode feeder throughout the electrolysis, the anode feeder being of a material that does not dissolve or passivate in the electrolyte under the reaction conditions during the elecrolysis, maintaining the temperature during the electrolsis at less than 70.degree. C., applying a positive current to the anode feeder to maintain an anode current density in the range 1 to 8 milliamps per square centimeter throughout the electrolysis and applying a negative current to a cathode spaced from the anode.
- 2. A method as claimed in claim 1 in which the substrates are rods and in which the starting current density is about 1.2 milliamps per square centimeter.
- 3. A method as claimed in claim 1 in which the substrates are cylinders and in which the starting current density is about three milliamps per square centimeter.
- 4. A method as claimed in claim 1 in which the temperature is maintained in the range 65.degree. to 69.degree. C.
- 5. A method as claimed in claim 1 in which the lead salt is lead nitrate.
- 6. A method as claimed in claim 1 in which the barrel is rotated 3.5 revolutions per minute.
- 7. A method as claimed in claim 1 in which the central anode feeder is also rotated.
- 8. A method as claimed in claim 1 in which the central anode feeder is of graphite.
- 9. A method of coating a plurality of rods with lead dioxide by electrolysis while the rods are immersed in an electrolyte at a temperature less than 70.degree. C. and containing a lead salt, comprising tumbling the rods in a porous barrel rotating about a fixed central anode feeder at a speed of 3.6 revolutions per minute with rods contacting the anode feeder throughout the electrolysis, the anode being of a material that does not dissolve or passivate in the electrolyte under the reaction conditions during the electrolysis, applying a positive current to the anode to produce a starting anode current density of about 1.25 milliamps per square centimeter and applying a negative current to a cathode spaced from the anode.
- 10. A method of coating a plurality of cylinders with lead dioxide by electrolysis while the cylinders are immersed in an electrolyte at a temperature in the range 65.degree. to 69.degree. C. and containing a lead salt, comprising tumbling the cylinders in a porous barrel rotating about a rotating central anode feeder, both the barrel and the feeder rotating at a speed of about 3.5 revolutions per minute with cylinders contacting the anode feeder throughout the electrolysis, the anode being of a material that does not dissolve or passivate in the electrolyte under the reaction conditions during the electrolysis, applying a positive current to the anode to produce a starting anode current density of about 3 milliamps per square centimeter and applying a negative current to a cathode spaced from the anode.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation in part of application Ser. No. 774,673 filed Mar. 7th, 1977, now abandoned.
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
900502 |
Ferchland et al. |
Oct 1908 |
|
925599 |
Russ et al. |
Jun 1909 |
|
1254046 |
King |
Jan 1918 |
|
2133324 |
Hosdowich |
Oct 1935 |
|
2606148 |
Portanova et al. |
Aug 1952 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
893823 |
Apr 1962 |
GBX |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
774673 |
Mar 1977 |
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