Systems and methods of protecting electrolysis cell sidewalls

Patent metadata

Field	Value
Publication number	US-2016068979-A1
Application number	US-201514847668-A
Country	US
Kind code	A1
Filing date	Sep 8, 2015
Priority date	Sep 10, 2014
Publication date	Mar 10, 2016
Grant date	—

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 feed material including the least one bath component to the molten electrolyte bath such that the at least one bath component is within 30% of saturation, wherein, via the feed material, the sidewall is stable in the molten electrolyte bath.

First claim

What is claimed is:

1 . A system, comprising:
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, wherein the sidewall has a thickness of 3 mm to not greater than 500 mm; and
a feed material including the least one bath component in the molten electrolyte bath such that the at least one bath component is within 90% of saturation, wherein, via the feed material, the sidewall is stable in the molten electrolyte bath.

2 . The system of claim 1 , wherein the saturation of the bath component is: at least about 95% of saturation.

3 . The system of claim 3 , wherein the saturation of the bath component is: not greater than 100% of saturation.

4 . The system of claim 1 , wherein the saturation percentage is measured at a location not greater than 6″ from the sidewall.

5 . The system of claim 1 , wherein the sidewall material is constructed of materials selected from the group consisting of: Al; Li; Na; K; Rb; Cs; Be; Mg; Ca; Sr; Ba; Sc; Y; La; or Ce-containing materials; Al; Li; Na; K; Rb; Cs; Be; Mg; Ca; Sr; Ba; Sc; Y; La; or Ce metals; Al; Li; Na; K; Rb; Cs; Be; Mg; Ca; Sr; Ba; Sc; Y; La; or Ce oxides; halide salt (e.g. fluoride salts of) Al; Li; Na; K; Rb; Cs; Be; Mg; Ca; Sr; Ba; Sc; Y; La; or Ce; oxofluoride of Al; Li; Na; K; Rb; Cs; Be; Mg; Ca; Sr; Ba; Sc; Y; La; or Ce; and combinations thereof.

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 having a trough width from 10 mm to not greater than 500 mm;
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.

7 . 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 second sidewall portion extends in an upward position relative to the cell bottom, such that the second sidewall portion overlaps with the first sidewall portion to provide a trough overlap from about 20% to 80% of the overall cell wall height; and
wherein the trough is configured to receive a protecting deposit and retain the protecting deposit separately from the cell bottom.

8 . The cell of claim 7 , 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.

9 . The cell of claim 7 , further 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 laterally spaced above the trough, such that the directing member is configured to direct the protecting deposit into the trough.

10 . The cell of claim 7 , wherein the second sidewall portion is configured to align with the first sidewall portion with respect to the thermal insulation package,
further wherein the second sidewall portion is configured to extend from the sidewall in a stepped configuration, and wherein the second sidewall portion comprises an upper surface and a side surface which define the stepped portion.

11 . The cell of claim 10 , wherein the upper surface of the second sidewall portion is a planar surface.

12 . The cell of claim 10 , wherein the upper surface of the sidewall portion is a sloped surface.

13 . The cell of claim 12 , wherein the upper surface in combination with the first sidewall portion are configured to cooperate and provide a recessed area configured to retain the protecting deposit therein.

14 . The cell of claim 7 , wherein the protecting deposit comprises the at least one bath component.

15 . The cell of claim 7 , wherein the trough is defined by a feed block constructed of a material selected from components in the bath chemistry, wherein via the bath chemistry, the feed block is maintained in the molten salt bath.

16 . The cell of claim 7 , further comprising a feeder configured to provide the protecting deposit in the trough.

Assignees

• Alcoa Inc

Inventors

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

Classifications

• C25C7/005 Primary

  of cells for the electrolysis of melts (C25C7/02 - C25C7/06 take precedence) · CPC title

• C25C3/14

  Devices for feeding or crust breaking · 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

• C25C3/20 Primary

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