Systems and methods of protecting electrolysis cell sidewalls

Patent metadata

Field	Value
Publication number	US-9771659-B2
Application number	US-201414206300-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 13, 2013
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A system is provided including an electrolysis cell configured to retain a molten electrolyte bath, the bath including at least one bath component, the electrolysis cell including: a bottom, and a sidewall consisting essentially of the at least one bath component; and a feeder system, configured to provide a feed material including the least one bath component to the molten electrolyte bath such that the at least one bath component is within 2% of saturation, wherein, via the feed material, the sidewall is stable in the molten electrolyte bath.

First claim

What is claimed is:

1. An electrolysis cell, comprising:
an anode;
a cathode in spaced relation from the anode;
a molten electrolyte bath in liquid communication with the anode and the cathode, wherein the molten electrolyte bath comprises a bath chemistry including at least one bath component;
a cell body having: a bottom and at least one sidewall surrounding the bottom, wherein the cell body is configured to retain the molten electrolyte bath, wherein the sidewall consists essentially of the at least one bath component, the sidewall further comprising:
a first sidewall portion, configured to fit onto a thermal insulation package of the sidewall and retain the electrolyte; and
a second sidewall portion configured to extend up from the bottom of the cell body,
wherein the second sidewall portion is longitudinally spaced from the first sidewall portion, such that the first sidewall portion, the second sidewall portion, and a base between the first portion and the second portion define a trough;
wherein the trough is configured to receive a protecting deposit and retain the protecting deposit separately from the cell bottom;
wherein the protecting deposit is configured to dissolve from the trough into the molten electrolyte bath such that the molten electrolyte bath comprises a level of the at least one bath component which is sufficient to maintain the first sidewall portion and second sidewall portion in the molten electrolyte bath.

2. The electrolysis cell of claim 1 , wherein the bath component comprises an average bath content of: within 1% of saturation.

3. The electrolysis cell of claim 1 , wherein the saturation of the bath component is: at least 95% of saturation.

4. The electrolysis cell of claim 1 , wherein the bath component comprises a bath content saturation percentage measured at a location adjacent to the sidewall.

5. The electrolysis cell of claim 4 , wherein the location adjacent to the sidewall further comprises: not greater than 6″ from the sidewall.

6. An electrolysis cell, comprising:
an anode;
a cathode in spaced relation from the anode;
a molten electrolyte bath in liquid communication with the anode and the cathode, wherein the molten electrolyte bath comprises a bath chemistry including at least one bath component;
a cell body having: a bottom and at least one sidewall surrounding the bottom, wherein the cell body is configured to retain the molten electrolyte bath, wherein the sidewall consists essentially of the at least one bath component, the sidewall further comprising:
a first sidewall portion, configured to fit onto a thermal insulation package of the sidewall and retain the electrolyte; and
a second sidewall portion configured to extend up from the bottom of the cell body, wherein the second sidewall portion is longitudinally spaced from the first sidewall portion, such that the first sidewall portion, the second sidewall portion, and a base between the first portion and the second portion define a trough; wherein the trough is configured to receive a protecting deposit and retain the protecting deposit separate from the cell bottom;
wherein the protecting deposit is configured to dissolve from the trough into the molten electrolyte bath such that the molten electrolyte bath comprises a level of the at least one bath component which is sufficient to maintain the first sidewall portion and second sidewall portion in the molten electrolyte bath; and

a directing member, wherein the directing member is positioned between the first sidewall portion and the second sidewall portion, further wherein the directing member is laterally spaced above the trough, such that the directing member is configured to direct the protecting deposit into the trough.

7. The electrolysis cell of claim 6 , wherein the bath component comprises an average bath content of: within 1% of saturation.

8. The electrolysis cell of claim 6 , wherein the saturation of the bath component is: at least 95% of saturation.

9. The electrolysis cell of claim 6 , wherein the bath component comprises a bath content saturation percentage measured at a location adjacent to the sidewall.

10. The electrolysis cell of claim 9 , wherein the location adjacent to the sidewall further comprises: not greater than 6″ from the sidewall.

11. An assembly, comprising:
an electrolysis sidewall having a first portion and a second portion,
wherein the second portion is configured to align with the first sidewall portion with respect to a thermal insulation package,
further wherein the second sidewall portion is configured to extend from the sidewall in a stepped configuration,
wherein the second sidewall portion comprises an upper surface and a side surface which define the stepped portion.

12. The assembly of claim 11 , wherein the upper surface is configured to provide a planar surface.

13. The assembly of claim 11 , wherein the upper surface is configured to provide a sloped surface, wherein the sloped surface comprises a slope towards the first sidewall portion to provide, via cooperation between the first sidewall portion and the upper surface of the second sidewall portion, a recessed area.

14. The assembly of claim 13 , wherein the recessed area is configured to retain a protecting deposit therein.

15. The assembly of claim 14 , wherein the protecting deposit comprises the at least one bath component.

16. The assembly of claim 11 , wherein a base comprises an at least one bath component.

17. The assembly of claim 16 , wherein the bath component comprises an average bath content of: within 1% of saturation.

18. The assembly of claim 16 , wherein the saturation of the bath component is: at least 95% of saturation.

19. The assembly of claim 16 , wherein the bath component comprises a bath content saturation percentage measured at a location adjacent to the sidewall.

20. The assembly of claim 19 , wherein the location adjacent to the sidewall further comprises: not greater than 6″ from the sidewall.

21. The assembly of claim 11 , wherein a protecting deposit extends from a trough and up to at least an upper surface of an electrolyte bath.

22. The assembly of claim 11 , comprising:
a directing member, wherein the directing member is positioned between the first sidewall portion and the second sidewall portion,
further wherein the directing member is positioned above a base of a trough, further wherein the directing member is configured to direct a protecting deposit into the trough.

23. The assembly of claim 22 , wherein the directing member is constructed of a material which is present in a bath chemistry, such that via the bath chemistry, the directing member is maintained in the molten salt electrolyte.

24. The assembly of claim 11 , wherein a base of a trough is defined by a feed block, wherein the feed block is constructed of a material selected from components in a bath chemistry, wherein via the bath chemistry, the feed block is maintained in the molten salt bath.

25. The assembly of claim 11 , further comprising a feeder configured to provide a protecting deposit in a trough.

26. A method, comprising:
passing current between an anode and a cathode through a molten electrolyte bath of an electrolytic cell,
feeding a feed material into the electrolytic cell to supply the molten electrolyte bath with at least one bath component,
wherein feeding is at a rate sufficient to maintain a bath conte

Assignees

• Alcoa Inc
• Alcoa Usa Corp

Inventors

• Liu Xinghua
• Weirauch Jr Douglas A
• Phelps Frankie E
• Dynys Joseph M
• Kerkhoff Jonell
• Dimilia Robert A

Classifications

• C25C3/20

  Automatic control or regulation of cells (controlling or regulating in general G05) · CPC title

• C25C3/08 Primary

  Cell construction, e.g. bottoms, walls, cathodes · CPC title

• C25C3/085

  characterised by its non electrically conducting heat insulating parts · CPC title

• C25C3/14

  Devices for feeding or crust breaking · CPC title