U.S. patent application number 15/928889 was filed with the patent office on 2018-07-26 for systems and methods of protecting electrolysis cell sidewalls.
The applicant listed for this patent is Alcoa USA Corp.. Invention is credited to Robert A. DiMilia, Joseph M. Dynys, Xinghua Liu, Jeffrey S. Martello.
Application Number | 20180209056 15/928889 |
Document ID | / |
Family ID | 55436998 |
Filed Date | 2018-07-26 |
United States Patent
Application |
20180209056 |
Kind Code |
A1 |
Liu; Xinghua ; et
al. |
July 26, 2018 |
SYSTEMS AND METHODS OF PROTECTING ELECTROLYSIS CELL SIDEWALLS
Abstract
Broadly, the present disclosure relates to sidewall features
(e.g. inner sidewall or hot face) of an electrolysis cell, which
protect the sidewall from the electrolytic bath while the cell is
in operation (e.g. producing metal in the electrolytic cell).
Inventors: |
Liu; Xinghua; (Murrysville,
PA) ; DiMilia; Robert A.; (Greensburg, PA) ;
Dynys; Joseph M.; (New Kensington, PA) ; Martello;
Jeffrey S.; (Murrysville, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Alcoa USA Corp. |
Pittsburgh |
PA |
US |
|
|
Family ID: |
55436998 |
Appl. No.: |
15/928889 |
Filed: |
March 22, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14847926 |
Sep 8, 2015 |
9957627 |
|
|
15928889 |
|
|
|
|
62048375 |
Sep 10, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25C 3/12 20130101; C25C
3/14 20130101; C25C 3/08 20130101; C25C 7/025 20130101; C25C 3/20
20130101; C25C 7/005 20130101 |
International
Class: |
C25C 3/20 20060101
C25C003/20; C25C 3/14 20060101 C25C003/14; C25C 3/08 20060101
C25C003/08 |
Claims
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; a cell body
comprising a sidewall and a bottom, wherein the cell body is
configured to retain the molten electrolyte bath; wherein the
sidewall comprises: a polarized sidewall portion, wherein the
polarized sidewall portion comprises not greater than 95% of the
sidewall and is in liquid communication with the molten electrolyte
bath, wherein the sidewall is from 5 mm thick to 500 mm thick.
2. The electrolysis cell of claim 1, wherein the polarized sidewall
portion is one of: an anodically polarized sidewall, a cathodically
polarized sidewall, and combinations thereof.
3. The electrolysis cell of claim 1, wherein polarized sidewall
portion comprises: a cathodically polarized sidewall, wherein the
cathodically polarized sidewall is positioned below the bath-vapor
interface and adjacent to the bottom of the cell body such that the
cathodically polarized sidewall is in liquid communication with the
bottom of the cell.
4. The electrolysis cell of claim 1, wherein the polarized sidewall
portion comprises: at least 50% of surface of the inner
sidewall.
5. The electrolysis cell of claim 1, wherein the apparatus
includes: a non-polarized sidewall portion, wherein both the
polarized sidewall portion and the non-polarized sidewall portion
are adjacent to each other and in liquid communication with the
molten electrolyte bath.
6. The electrolysis cell of claim 1, wherein the non-polarized
sidewall portion is positioned above the cathodically polarized
sidewall and is in communication with the bath-air interface.
7. The electrolysis cell of claim 5, wherein the non-polarized
sidewall portion is selected from the group consisting of: a
thermal conductor; a stable material; a frozen ledge device, and
combinations thereof.
8. The electrolysis cell of claim 5, wherein the non-polarized
sidewall is configured to extend from the cell bottom to a height
above a metal-to-bath interface, further wherein the non-polarized
sidewall portion is configured adjacent to and in communication
with the anodically polarized sidewall.
9. The electrolysis cell of claim 1, wherein the polarized sidewall
portion comprises: an anodically polarized sidewall, wherein the
anodically polarized sidewall is positioned above the bottom of the
cell body and adjacent to the bath-vapor interface, such that the
anodically polarized sidewall is in communication with the
bath-vapor interface.
10. An electrolysis cell comprising: a cell body having a bottom
and at least one sidewall, wherein the cell body is configured to
retain a molten electrolyte bath, wherein the sidewall comprises: a
first sidewall portion, configured to fit onto a thermal insulation
package of the sidewall and retain the electrolyte, the first
sidewall portion comprising an anodically polarized sidewall
portion; 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 sidewall portion define a
trough the trough having a width of 10 mm to not greater than 500
mm; wherein the trough is configured to receive a protecting
deposit and retain the protecting deposit separate from the cell
bottom.
11. The electrolysis cell of claim 10, wherein the second sidewall
portion comprises a cathodically polarized sidewall.
12. The electrolysis cell of claim 10, wherein the second sidewall
portion comprises a non-polarized sidewall including a stable
material, wherein the stable material which includes a component of
the bath chemistry further wherein, via the bath chemistry and
percent saturation of the non-reactive material in the bath, the
sidewall is substantially non-reactive in the molten salt
electrolyte.
13. The electrolysis cell of claim 10, further comprising a
directing member, wherein the directing member is positioned
between the anodically polarized sidewall and the second sidewall
portion, further wherein the directing member is laterally spaced
above the base of the trough, such that the directing member is
configured to direct a feed material into the trough, to be
retained therein as protecting deposit in the trough.
14. The electrolysis cell of claim 10, wherein the directing member
comprises: an anodically polarized material; a stable material; a
cathodically polarized material; and combinations thereof.
15. An assembly comprising: a cell body having a bottom and at
least one sidewall, wherein the cell body is configured to retain a
molten electrolyte bath, wherein the sidewall comprises: a first
sidewall portion comprising an anodically polarized sidewall,
wherein the anodically polarized sidewall is configured to fit onto
a thermal insulation package of the sidewall and retain the
electrolyte; and a second sidewall portion comprising a
cathodically polarized sidewall, the cathodically polarized
sidewall configured to extend up from the bottom of the cell body,
wherein the cathodically polarized sidewall is longitudinally
spaced from the anodically polarized sidewall, such that the
anodically polarized sidewall and the cathodically polarized
sidewall define a gap there between; and a non-polarized sidewall
portion configured to fit in the gap between the anodically
polarized sidewall and the cathodically polarized sidewall, wherein
via the non-polarized sidewall portion, the anodically polarized
sidewall is insulated from the cathodically polarized sidewall.
16. A method, comprising: passing current from an anode through a
molten electrolyte bath to a cathode in an electrolysis cell;
feeding a feed material into the electrolysis cell at a location
adjacent to a cell wall, such that the feed material is retained in
a trough defined adjacent to the sidewall; and via the feeding
step, maintaining the sidewall in the molten electrolyte during
cell operation, wherein the sidewall is constructed of at least one
component which is within about 95% of saturation in the molten
electrolyte bath.
17. The method of claim 16, further comprising: concomitant to the
first step, maintaining the bath at a temperature not exceeding
980.degree. C., wherein the sidewalls of the cells are
substantially free of a frozen ledge.
18. The method of claim 16, wherein the method includes: consuming
the protecting deposit such that via consumption of the protecting
deposit, metal ions are supplied to the molten electrolyte
bath.
19. The method of claim 16, further comprising: producing a metal
product from the at least one bath component.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent
application Ser. No. 14/847,926 filed Sep. 8, 2015, which claims
priority to U.S. Patent Application No. 62/048,375 filed Sep. 10,
2014, which are incorporated herein by reference in their
entirety.
FIELD OF THE INVENTION
[0002] Broadly, the present disclosure relates to sidewall features
(e.g. inner sidewall or hot face) of an electrolysis cell, which
protect the sidewall from the electrolytic bath while the cell is
in operation (e.g. producing metal in the electrolytic cell). More
specifically, in one or more embodiments of the instant disclosure,
the inner sidewall features provide for direct contact with the
metal, bath, and/or vapor in an electrolytic cell in the absence of
the frozen ledge along the entire or a portion of inner
sidewall.
BACKGROUND
[0003] Traditionally, sidewalls of an electrolysis cell are
constructed of thermally conductive materials to form a frozen
ledge along the entire sidewall (and upper surface of the bath) to
maintain cell integrity. Through the various embodiments of the
instant disclosure, the sidewall is replaced, at least in part, by
one or more sidewall embodiments of the instant disclosure.
SUMMARY OF THE DISCLOSURE
[0004] In some embodiments, a stable sidewall material is provided,
which is stable (e.g. substantially non-reactive) in the molten
electrolyte (e.g. the cell bath) by maintaining one or more
components in the bath chemistry at a certain percentage of
saturation. In some embodiments, the bath chemistry is maintained
via at least one feeding device in the cell (e.g. located along the
sidewall), which provides a feed material into the cell (e.g. which
is retained as a protecting deposit located adjacent to the
sidewall of the cell). In some embodiments, the protecting depict
supplies at least one bath component (e.g. alumina) to the bath
(e.g. to the bath immediately adjacent to the sidewall). As a
non-limiting example, as the protecting deposit is slowly
dissolved, the bath chemistry adjacent to the sidewall is at or
near saturation for that bath component, thus protecting the
sidewall from dissolving (e.g. solubilizing/corroding) by
interacting with the molten electrolyte/bath. In some embodiments,
the percent saturation of the bath for a particular bath component
(e.g. alumina) is a function of the feed material concentration
(e.g. alumina) at cell operating conditions (e.g. temperature, bath
ratio, and bath chemistry, and/or content).
[0005] In some embodiments, a polarized sidewall (e.g. anodically
polarized sidewall and/or cathodically polarized sidewall) actively
assists in conducting current into or out of the wall, where such
polarized materials are resistant to: the vapor phase, the bath/air
interface, the bath, the bath/metal interface, the metal pad, and
combinations thereof.
[0006] In some embodiments, a frozen ledge device and/or thermal
conductor (e.g. insulating material) comprises at least a portion
of the sidewall and is configured to extract heat from the bath at
a specific location to define a localized frozen ledge along a
portion of the sidewall. In some embodiments, the localized frozen
edge is configured as an electrical insulator between oppositely
polarized sidewall portions and/or interfaces (e.g. bath-vapor
interface or metal-bath interface). In some embodiments, the frozen
ledge device and/or thermal conductor materials are utilized in
conjunction with at least one of (a) a non-reactive sidewall
material (also called a stable sidewall material) and/or (b) a
polarized sidewall material. In some embodiments, the frozen ledge
device is adjustable, repositionable and/or removable. In some
embodiments, the frozen ledge device is integral (e.g. part of) the
sidewall.
[0007] In some embodiments, the sidewalls of the instant disclosure
provide for an energy savings of: at least about 5%; at least about
10%; at least about 15%; at least about 20%; at least about 25%; or
at least about 30% over the traditional thermally conductive
material package.
[0008] In some embodiments, the heat flux (i.e. heat lost through
the sidewall of the cell during cell operation) is: not greater
than about 8 kW/m.sup.2; not greater than about 4 kW/m.sup.2; not
greater than about 3 kW/m.sup.2; not greater than about 2
kW/m.sup.2; not greater than about 1 kW/m.sup.2; not greater than
about 0.75 kW/m.sup.2.
[0009] In some embodiments, the heat flux (i.e. heat lost through
the sidewall of the cell during cell operation) is: at least about
8 kW/m.sup.2; at least about 4 kW/m.sup.2; at least about 3
kW/m.sup.2; at least about 2 kW/m.sup.2; at least about 1
kW/m.sup.2; at least about 0.75 kW/m.sup.2.
[0010] In stark contrast, commercial Hall cells operate with a heat
flux through the sidewall of between about 8-15 kW/m.sup.2.
[0011] In one or more embodiments of the instant disclosure,
active/dynamic side/end walls for metal electrolytic cells are
provided, wherein the inside portion (inner wall) of the sidewall
is positively polarized, negatively polarized, or combined
(positively and negatively polarized--with an insulator between the
positive and negative sidewall portions). In one or more
embodiments of the instant disclosure, the middle portion
(insulator) is built with thermal and electrical insulation
materials to prevent heat loss. In one or more embodiments, the
outside of the sidewall is a shell (e.g. steel) for structural
stability. In some embodiments, stable materials and/or localized
freezing are utilized and specifically designed/configured to
extend across the gap (e.g. seal and/or electrically insulate) in
the dynamic (active) side/end walls.
[0012] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
comprising a sidewall and a bottom, wherein the cell body is
configured to retain the molten electrolyte bath; wherein the
sidewall comprises: a polarized sidewall portion, wherein the
polarized sidewall portion comprises not greater than 95% of the
sidewall and is in liquid communication with the molten electrolyte
bath, wherein the sidewall is from 5 mm thick to 500 mm thick.
[0013] In some embodiments, the polarized sidewall portion is one
of: an anodically polarized sidewall, a cathodically polarized
sidewall, and combinations thereof.
[0014] In some embodiments, the polarized sidewall portion
comprises: a cathodically polarized sidewall, wherein the
cathodically polarized sidewall is positioned below the bath-vapor
interface and adjacent to the bottom of the cell body such that the
cathodically polarized sidewall is in liquid communication with the
bottom of the cell.
[0015] In some embodiments, the polarized sidewall portion
comprises: at least 50% of surface of the inner sidewall.
[0016] In some embodiments, the apparatus includes: a non-polarized
sidewall portion, wherein both the polarized sidewall portion and
the non-polarized sidewall portion are adjacent to each other and
in liquid communication with the molten electrolyte bath.
[0017] In some embodiments, the non-polarized sidewall portion is
positioned above the cathodically polarized sidewall and is in
communication with the bath-air interface.
[0018] In some embodiments, the non-polarized sidewall portion is
selected from the group consisting of: a thermal conductor; a
stable material; a frozen ledge device, and combinations
thereof.
[0019] In some embodiments, the non-polarized sidewall is
configured to extend from the cell bottom to a height above a
metal-to-bath interface, further wherein the non-polarized sidewall
portion is configured adjacent to and in communication with the
anodically polarized sidewall.
[0020] In some embodiments, the polarized sidewall portion
comprises: an anodically polarized sidewall, wherein the anodically
polarized sidewall is positioned above the bottom of the cell body
and adjacent to the bath-vapor interface, such that the anodically
polarized sidewall is in communication with the bath-vapor
interface.
[0021] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: a cell body having a bottom and at
least one sidewall, wherein the cell body is configured to retain a
molten electrolyte bath, wherein the sidewall comprises: a first
sidewall portion, configured to fit onto a thermal insulation
package of the sidewall and retain the electrolyte, the first
sidewall portion comprising an anodically polarized sidewall
portion; 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 sidewall portion define a
trough the trough having a width of 10 mm to not greater than 500
mm; wherein the trough is configured to receive a protecting
deposit and retain the protecting deposit separate from the cell
bottom.
[0022] In some embodiments, the second sidewall portion comprises a
cathodically polarized sidewall.
[0023] In some embodiments, the second sidewall portion comprises a
non-polarized sidewall including a stable material, wherein the
stable material which includes a component of the bath chemistry
further wherein, via the bath chemistry and percent saturation of
the non-reactive material in the bath, the sidewall is
substantially non-reactive in the molten salt electrolyte.
[0024] In some embodiments, the cell comprises a directing member,
wherein the directing member is positioned between the anodically
polarized sidewall and the second sidewall portion, further wherein
the directing member is laterally spaced above the base of the
trough, such that the directing member is configured to direct a
feed material into the trough, to be retained therein as protecting
deposit in the trough.
[0025] In some embodiments, the directing member comprises: an
anodically polarized material; a stable material; a cathodically
polarized material; and combinations thereof.
[0026] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion comprising an anodically polarized sidewall, wherein the
anodically polarized sidewall is configured to fit onto a thermal
insulation package of the sidewall and retain the electrolyte; and
a second sidewall portion comprising a cathodically polarized
sidewall, the cathodically polarized sidewall configured to extend
up from the bottom of the cell body, wherein the cathodically
polarized sidewall is longitudinally spaced from the anodically
polarized sidewall, such that the anodically polarized sidewall and
the cathodically polarized sidewall define a gap there between; and
a non-polarized sidewall portion configured to fit in the gap
between the anodically polarized sidewall and the cathodically
polarized sidewall, wherein via the non-polarized sidewall portion,
the anodically polarized sidewall is insulated from the
cathodically polarized sidewall.
[0027] In one aspect, a method is provided, comprising: passing
current from an anode through a molten electrolyte bath to a
cathode in an electrolysis cell; feeding a feed material into the
electrolysis cell at a location adjacent to a cell wall, such that
the feed material is retained in a trough defined adjacent to the
sidewall; and via the feeding step, maintaining the sidewall in the
molten electrolyte during cell operation, wherein the sidewall is
constructed of at least one component which is within about 95% of
saturation in the molten electrolyte bath.
[0028] In some embodiments, the method includes: concomitant to the
first step, maintaining the bath at a temperature not exceeding
980.degree. C., wherein the sidewalls of the cells are
substantially free of a frozen ledge.
[0029] In some embodiments, the method includes: consuming the
protecting deposit such that via consumption of the protecting
deposit, metal ions are supplied to the molten electrolyte
bath.
[0030] In some embodiments, the method includes producing a metal
product from the at least one bath component.
[0031] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
comprising a sidewall and a bottom, wherein the cell body is
configured to retain the molten electrolyte bath; wherein the
sidewall comprises: a polarized sidewall portion wherein the
polarized sidewall portion is in liquid communication with the
molten electrolyte bath.
[0032] In one aspect of the instant disclosure, an electrolysis
cell wall is provided, comprising: a cell body comprising a
sidewall and a bottom, wherein the cell body is configured to
retain a molten electrolyte bath; wherein the sidewall comprises: a
polarized sidewall portion, wherein the polarized sidewall portion
is configured to be in liquid communication with the molten
electrolyte bath.
[0033] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
comprising a sidewall and a bottom, wherein the cell body is
configured to retain the molten electrolyte bath; wherein the
sidewall comprises: a polarized sidewall portion and a
non-polarized sidewall portion, wherein both the polarized sidewall
portion and the non-polarized sidewall portion are adjacent to each
other and in liquid communication with the molten electrolyte
bath.
[0034] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
comprising a sidewall and a bottom, wherein the cell body is
configured to retain the molten electrolyte bath; wherein the
sidewall comprises: a polarized sidewall portion comprising at
least about 50% of the sidewall and a non-polarized sidewall
portion, wherein both the polarized sidewall portion and the
non-polarized sidewall portion are adjacent to each other and in
liquid communication with the molten electrolyte bath.
[0035] In one aspect of the instant disclosure, an electrolysis
cell sidewall is provided, comprising: a cell body comprising a
sidewall and a bottom, wherein the cell body is configured to
retain a molten electrolyte bath; wherein the sidewall comprises: a
polarized sidewall portion (e.g. comprising from about 1% to about
100% of the sidewall), wherein the polarized sidewall portion is
configured to be in liquid communication with the molten
electrolyte bath.
[0036] In some embodiments, the polarized sidewall portion is
selected from: an anodically polarized sidewall, a cathodically
polarized sidewall, and combinations thereof.
[0037] In some embodiments, the non-polarized sidewall portion is
selected from the group consisting essentially of: a thermal
conductor; a stable material (non-reactive material); a frozen
ledge device, and combinations thereof.
[0038] In some embodiments, the polarized sidewall comprises: a
cathodic sidewall, wherein the cathodically polarized sidewall
portion is positioned adjacent to and in communication with the
bottom of the cell body (e.g. below the bath-vapor interface);
further wherein the non-polarized sidewall portion is positioned
above the cathodically polarized sidewall portion and is in
communication with the bath-air interface.
[0039] In some embodiments, the polarized sidewall comprises an
anodically polarized sidewall portion, wherein the anodic sidewall
is positioned adjacent to and in communication with the bath-vapor
interface and above the bottom of the cell body (e.g. above the
bath-metal interface; or out of direct contact with a cathode block
or a cathodic cell bottom); further wherein the non-polarized
sidewall portion is positioned below the anodically polarized
sidewall portion and is in communication with at least one of: (a)
the bath-metal interface and (b) the cell bottom.
[0040] In one aspect of the instant disclosure, an electrolysis
cell sidewall is provided, comprising: a cell body comprising a
sidewall and a bottom, wherein the cell body is configured to
retain a molten electrolyte bath; wherein the sidewall comprises: a
polarized sidewall portion and a non-polarized sidewall portion,
wherein both the polarized sidewall portion and the non-polarized
sidewall portion are adjacent to each other and in liquid
communication with the molten electrolyte bath.
[0041] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
including: at least one sidewall and a bottom, wherein the cell
body is configured to retain the molten electrolyte bath; wherein
the sidewall comprises: an anodic polarized sidewall portion in
liquid communication with the electrolyte bath, wherein the anodic
polarized sidewall is positioned above and remote from the bottom
of the cell body and in communication with the bath-to-air/vapor
interface; and a non-polarized sidewall material adjacent to the
anodic polarized sidewall portion and in liquid communication with
at least one of: (a) a metal pad and (b) a cell bottom.
[0042] In some embodiments, non-polarized sidewall is configured to
extend from the cell bottom to a height above a metal pad-to-bath
interface.
[0043] In one aspect of the instant disclosure, an electrolysis
sidewall is provided, comprising: a cell body including: at least
one sidewall and a bottom, wherein the cell body is configured to
retain a molten electrolyte bath; wherein the sidewall comprises:
an anodic polarized sidewall portion in liquid communication with
the electrolyte bath, wherein the anodic polarized sidewall is
positioned above and remote from the bottom of the cell body in
communication with the bath-to-vapor interface; and a non-polarized
sidewall material adjacent to the anodic polarized sidewall portion
and in liquid communication with at least one of: (a) a metal pad
and (b) a cell bottom.
[0044] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
including: at least one sidewall and a bottom, wherein the cell
body is configured to retain the molten electrolyte bath; wherein
the sidewall comprises: an anodic polarized sidewall portion in
liquid communication with the electrolyte bath, wherein the anodic
polarized sidewall is positioned above and remote from the bottom
of the cell body in communication with the bath-to-air interface;
and a non-polarized sidewall material comprising a thermal
conductor adjacent to the anodic polarized sidewall portion and in
liquid communication with at least one of: (a) a metal pad and (b)
a cell bottom, wherein the thermal conductor is configured to
accept heat from the molten electrolyte bath adjacent to a thermal
conductor contact point, wherein, via the thermal conductor, a
frozen ledge (e.g. localized) is formed between the thermal
conductor and molten electrolyte bath along a portion of the
sidewall. As a non-limiting example, the thermal conductor is
configured to insulate the anodically polarized sidewall portion
from the cathodic portion (e.g. metal pad, cathode, or cell
bottom).
[0045] In one aspect of the instant disclosure, an electrolysis
sidewall is provided, comprising: a cell body including: at least
one sidewall and a bottom, wherein the cell body is configured to
retain a molten electrolyte bath; wherein the sidewall comprises:
an anodic polarized sidewall portion in liquid communication with
the electrolyte bath, wherein the anodic polarized sidewall is
positioned above and remote from the bottom of the cell body in
communication with the bath-to-air interface; and a non-polarized
sidewall material comprising a thermal conductor adjacent to the
anodic polarized sidewall portion and in liquid communication with
a cell bottom, wherein the thermal conductor is configured to
accept heat from the molten electrolyte bath adjacent to a thermal
conductor contact point, wherein, via the thermal conductor, a
frozen ledge is formed between the thermal conductor and molten
electrolyte bath along a portion of the sidewall.
[0046] In some embodiments, the metal product is drained from cell
bottom.
[0047] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
including: at least one sidewall and a bottom, wherein the cell
body is configured to retain the molten electrolyte bath; wherein
the sidewall comprises: an anodic polarized sidewall portion in
liquid communication with the electrolyte bath, wherein the anodic
polarized sidewall is positioned above and remote from the bottom
of the cell body in communication with the bath-to-vapor interface;
and a non-polarized sidewall portion adjacent to the anodic
polarized sidewall portion and in liquid communication with at
least one of: (a) a metal pad and (b) a cell bottom, wherein the
non-polarized sidewall comprises a non-reactive material which is a
component of the bath chemistry; further wherein, via the bath
chemistry and percent saturation of the non-reactive material in
the bath, the sidewall is substantially non-reactive with the
molten salt electrolyte (e.g. during cell operation).
[0048] In one aspect of the instant disclosure, an electrolysis
sidewall is provided, comprising: a cell body including: at least
one sidewall and a bottom, wherein the cell body is configured to
retain a molten electrolyte bath; wherein the sidewall comprises:
an anodic polarized sidewall portion in liquid communication with
the electrolyte bath, wherein the anodic polarized sidewall is
positioned above and remote from the bottom of the cell body in
communication with the bath-to-air interface; and a non-polarized
sidewall portion adjacent to the anodic polarized sidewall portion
and in liquid communication with at least one of: (a) a metal pad
and (b) a cell bottom, wherein the non-polarized sidewall comprises
a non-reactive material which is a component of the bath chemistry;
further wherein, via the bath chemistry and percent saturation of
the non-reactive material in the bath, the sidewall is
substantially non-reactive with the molten salt electrolyte (e.g.
during cell operation).
[0049] In some embodiments, the non-polarized sidewall portion
(e.g. stable sidewall) is configured to extend out from the
sidewall (e.g. sidewall profile) and provide a stepped
configuration. In some embodiments, the cell is configured with a
feeder, which provides a feed into the bath, which is retained
along at least a portion of (e.g. along the top and/or side) of the
stepped out portion of stable sidewall material. In some
embodiments, the stable sidewall material is located adjacent to
and in communication with the anodically polarized sidewall portion
(i.e. such that the anodically polarized sidewall portion extends
the entire length of the thermal insulation package, and the stable
sidewall material is configured to fit over a portion of the
anodically polarized sidewall portion in proximity to the metal pad
and/or bath-metal pad interface). In some embodiments, the top
surface of the stable sidewall material is flat. In some
embodiments, the top portion/surface of the stable sidewall is
sloped (e.g. towards the anodically polarized sidewall). In some
embodiments, the sloped stable sidewall together with the
anodically polarized sidewall to define a trough, which is
configured to retain a protecting deposit therein. In some
embodiments, the sloped stable sidewall is sloped towards the
center of the cell/metal pad (away from the sidewall).
[0050] In one aspect, an electrolysis cell is provided, comprising:
an anode; a cathode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
including: at least one sidewall and a bottom, wherein the cell
body is configured to retain the molten electrolyte bath; wherein
the sidewall comprises: an anodic polarized sidewall portion in
liquid communication with the electrolyte bath, wherein the anodic
polarized sidewall is positioned above and remote from the bottom
of the cell body in communication with the bath-to-air interface;
and a non-polarized sidewall portion adjacent to the anodic
polarized sidewall portion and in communication with at least one
of: (a) a metal pad and (b) a cell bottom, wherein the
non-polarized sidewall comprises a frozen ledge device: wherein,
via the frozen ledge device, heat is extracted from the molten salt
bath adjacent to the frozen ledge device to define a frozen ledge
along a portion of the sidewall adjacent to the frozen ledge
device.
[0051] In one aspect of the instant disclosure, an electrolysis
sidewall is provided, comprising: a cell body including: at least
one sidewall and a bottom, wherein the cell body is configured to
retain a molten electrolyte bath; wherein the sidewall comprises:
an anodic polarized sidewall portion in liquid communication with
the electrolyte bath, wherein the anodic polarized sidewall is
positioned above and remote from the bottom of the cell body in
communication with the bath-to-vapor interface; and a non-polarized
sidewall portion adjacent to the anodic polarized sidewall portion
and in communication with a cell bottom, wherein the non-polarized
sidewall comprises a frozen ledge device: wherein, via the frozen
ledge device, heat is extracted from the molten salt bath adjacent
to the frozen ledge device to define a frozen ledge along a portion
of the sidewall adjacent to the frozen ledge device.
[0052] In some embodiments, the metal product is drained from
cell.
[0053] In some embodiments, the frozen ledge device comprises: a
body having an inlet and an outlet; a heat exchanger channel,
wherein the heat exchanger channel extends along the inside of the
body and in liquid communication with the inlet and the outlet; and
a coolant, wherein the coolant travels along a flow path defined by
the heat exchanger channel, the inlet, and the outlet.
[0054] In some embodiments, the channel comprises a plurality of
expanded areas along the outer body wall, wherein the expanded
areas are configured to provide increased surface area for heat
transfer from the molten electrolyte bath into the coolant.
[0055] In some embodiments, the coolant is selected from: argon,
nitrogen, and air.
[0056] In some embodiments, the expanded area further comprises a
plurality of fins.
[0057] In some embodiments, the frozen ledge device extracts at
least about 5 kW/m.sup.2 heat flux from the electrolysis cell.
[0058] In some embodiments, the frozen ledge device further
comprises a heat exchanger attached to the coolant outlet.
[0059] In some embodiments, the non-polarized sidewall portion is
configured to maintain heat loss across the non-polarized sidewall
portion to not greater than about 8 KW/m.sup.2.
[0060] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion, configured to fit
onto a thermal insulation package of the sidewall and retain the
electrolyte, the first sidewall portion comprising an anodic
polarized sidewall portion; 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 (e.g. metal pad).
[0061] In one aspect of the instant disclosure, an electrolysis
cell sidewall is provided, comprising: a cell body having a bottom
and at least one sidewall, wherein the cell body is configured to
retain a molten electrolyte bath, wherein the sidewall comprises: a
first sidewall portion, configured to fit onto a thermal insulation
package of the sidewall and retain the electrolyte, the first
sidewall portion comprising an anodic polarized sidewall portion;
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 sidewall portion define a
trough; wherein the trough is configured to receive a protecting
deposit and retain the protecting deposit separate from the cell
bottom (e.g. metal pad).
[0062] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion including an anodic
polarized sidewall portion, configured to fit onto a thermal
insulation package of the sidewall and retain the electrolyte; 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
(e.g. metal pad); and a directing member, wherein the directing
member is positioned between the anodic sidewall portion and the
second sidewall portion, further wherein the directing member is
laterally spaced above the base of the trough, such that the
directing member is configured to direct the protecting deposit
into the trough.
[0063] In some embodiments, the directing member comprises an
anodically polarized material. In some embodiments, the directing
member comprises a non-reactive (e.g. stable) material. In some
embodiments, the directing member comprises a cathodically
polarized material.
[0064] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion comprising an anodic
polarized sidewall portion, configured to fit onto a thermal
insulation package of the sidewall and retain the electrolyte; 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 and the second sidewall portion define a
gap; and a thermal conductor configured to fit in the gap and
extend between the first sidewall portion and the second sidewall
portion; wherein thermal conductor is configured to accept heat
from the molten electrolyte bath, wherein, via a heat transfer from
the molten electrolyte bath through the sidewall from the thermal
conductor, a frozen ledge is formed between the thermal conductor
and molten electrolyte, which spans the gap between the first
sidewall portion and the second sidewall portion.
[0065] In one aspect of the instant disclosure, an electrolysis
cell assembly is provided, comprising: a cell body having a bottom
and at least one sidewall, wherein the cell body is configured to
retain a molten electrolyte bath, wherein the sidewall comprises: a
first sidewall portion comprising an anodic polarized sidewall
portion, configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte; 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 and the
second sidewall portion define a gap; and a thermal conductor
configured to fit in the gap and extend between the first sidewall
portion and the second sidewall portion; wherein the thermal
conductor is configured to accept heat from the molten electrolyte
bath, wherein, via a heat transfer from the molten electrolyte bath
through the sidewall from the thermal conductor, a frozen ledge is
formed between the thermal conductor and molten electrolyte, which
spans the gap between the first sidewall portion and the second
sidewall portion.
[0066] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion comprising an anodic
polarized sidewall portion, configured to fit onto a thermal
insulation package of the sidewall and retain the electrolyte; 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 and the second sidewall portion define a
gap; and a frozen ledge device configured to fit in the gap between
the first sidewall portion and the second sidewall portion, wherein
via the frozen ledge device, heat is extracted from the molten
electrolyte bath to define a frozen ledge along the frozen ledge
device extending between the first sidewall portion and the second
sidewall portion.
[0067] In one aspect of the instant disclosure, an electrolysis
cell assembly is provided, comprising: a cell body having a bottom
and at least one sidewall, wherein the cell body is configured to
retain a molten electrolyte bath, wherein the sidewall comprises: a
first sidewall portion comprising an anodic polarized sidewall
portion, configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte; 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 and the
second sidewall portion define a gap; and a frozen ledge device
configured to fit in the gap between the first sidewall portion and
the second sidewall portion, wherein via the frozen ledge device,
heat is extracted from the molten electrolyte bath to define a
frozen ledge along the frozen ledge device extending between the
first sidewall portion and the second sidewall portion.
[0068] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
sidewall comprises: a cathodically polarized sidewall portion in
liquid communication with the molten electrolyte, wherein the
cathodically polarized sidewall is positioned adjacent to and in
communication with the bottom of the cell body (e.g. across the
bath-metal interface) and extends above the bath-vapor interface.
In this embodiment, the cathodic sidewall has a localized frozen
ledge where the cathodic sidewall portion extends above the
bath-vapor interface.
[0069] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
sidewall comprises: a cathodically polarized sidewall portion in
liquid communication with the molten electrolyte, wherein the
cathodically polarized sidewall is positioned adjacent to and in
communication with the bottom of the cell body (e.g. across the
bath-metal interface); and a non-polarized sidewall portion
adjacent to and in communication with the cathodically polarized
sidewall portion, wherein the non-polarized sidewall portion is
located adjacent to and in communication with the bath-air
interface.
[0070] In some embodiments, the sidewall comprises a portion of
thermally conductive material along the bath-to-air interface to
remove heat from the bath and/or create a frozen portion along the
bath-to-air interface.
[0071] In some embodiments, the sidewall comprises a portion of
refractory wall adjacent to/on top of the thermally conductive
material.
[0072] In one aspect of the instant disclosure, an electrolysis
cell assembly is provided, comprising: a cell body configured to
retain a molten electrolyte bath, wherein the cell body comprises:
at least one sidewall and a bottom; wherein the sidewall comprises:
a cathodically polarized sidewall portion in liquid communication
with the molten electrolyte, wherein the cathodically polarized
sidewall is positioned adjacent to and in communication with the
bottom of the cell body (e.g. across the bath-metal interface); and
a non-polarized sidewall portion adjacent to and in communication
with the cathodically polarized sidewall portion, wherein the
non-polarized sidewall portion is located adjacent to and in
communication with the bath-vapor interface.
[0073] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
sidewall comprises: a cathodically polarized sidewall portion in
liquid communication with the molten electrolyte bath, wherein the
cathodically polarized sidewall is positioned adjacent to and in
communication with the bottom of the cell body (e.g. across the
bath-metal interface); and a non-polarized sidewall portion
adjacent to and in communication with the cathodically polarized
sidewall portion, wherein the non-polarized sidewall portion is
located adjacent to and in communication with the bath-air
interface, wherein the non-polarized sidewall comprises a
non-reactive material which is a component of the bath chemistry
further wherein, via the bath chemistry and percent saturation of
the non-reactive material in the bath, the sidewall is
substantially non-reactive with the molten salt electrolyte (e.g.
during cell operation).
[0074] In some embodiments, the non-polarized sidewall (stable
sidewall/first sidewall portion) extends the entire length of the
thermal insulation package (i.e. to the cell bottom) and the
cathodic sidewall is configured to attach immediately adjacent to
and in communication with the stable sidewall material, such that
the cathodic sidewall is in liquid communication with at least one
of (1) the metal pad; and (2) the bath-metal pad interface. In some
embodiments, the cathodic sidewall has a flat top portion. In some
embodiments, the cathodic sidewall has a sloped top portion (i.e.
sloped towards the stable sidewall to define a recessed area/trough
therein). In some embodiments, the cathodic sidewall has a sloped
top portion (i.e. sloped towards the metal pad/canter of the cell
(to assist in draining metal product to the bottom of the cell). In
some embodiments, the cell further comprises a feeder, which is
configured to provide a feed to the cell, which is retained in the
sloped top portion of the cathodic sidewall as a protecting
deposit.
[0075] In one aspect of the instant disclosure, an electrolysis
cell assembly is provided, comprising: a cell body configured to
retain a molten electrolyte bath, wherein the cell body comprises:
at least one sidewall and a bottom; wherein the sidewall comprises:
a cathodically polarized sidewall portion in liquid communication
with the molten electrolyte bath, wherein the cathodically
polarized sidewall is positioned adjacent to and in communication
with the bottom of the cell body (e.g. across the bath-metal
interface); and a non-polarized sidewall portion adjacent to and in
communication with the cathodically polarized sidewall portion,
wherein the non-polarized sidewall portion is located adjacent to
and in communication with the bath-vapor interface, wherein the
non-polarized sidewall comprises a non-reactive material which is a
component of the bath chemistry further wherein, via the bath
chemistry and percent saturation of the non-reactive material in
the bath, the sidewall is substantially non-reactive with the
molten salt electrolyte (e.g. during cell operation).
[0076] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
sidewall comprises: a cathodically polarized sidewall portion in
liquid communication with the electrolyte bath, wherein the
cathodically polarized sidewall is positioned adjacent to and in
communication with the bottom of the cell body (e.g. across the
bath-metal interface); and a non-polarized sidewall portion
adjacent to and in communication with the cathodically polarized
sidewall portion, wherein the non-polarized sidewall portion is
located adjacent to and in communication with the bath-air
interface, wherein the non-polarized sidewall comprises a frozen
ledge device, wherein, via the frozen ledge device, heat is
extracted from the molten salt bath adjacent to the frozen ledge
device to define a frozen ledge along a portion of the sidewall
adjacent to the frozen ledge device.
[0077] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body configured to retain a molten
electrolyte bath, wherein the cell body comprises: at least one
sidewall and a bottom; wherein the sidewall comprises: a
cathodically polarized sidewall portion in liquid communication
with the electrolyte bath, wherein the cathodically polarized
sidewall is positioned adjacent to and in communication with the
bottom of the cell body (e.g. across the bath-metal interface); and
a non-polarized sidewall portion adjacent to and in communication
with the cathodically polarized sidewall portion, wherein the
non-polarized sidewall portion is located adjacent to and in
communication with the bath-air interface, wherein the
non-polarized sidewall comprises a frozen ledge device, wherein,
via the frozen ledge device, heat is extracted from the molten salt
bath adjacent to the frozen ledge device to define a frozen ledge
along a portion of the sidewall adjacent to the frozen ledge
device.
[0078] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
sidewall comprises: a cathodically polarized sidewall portion in
liquid communication with the electrolyte bath, wherein the
cathodically polarized sidewall is positioned adjacent to and in
communication with the bottom of the cell body (e.g. across the
bath-metal interface, in communication with the metal pad); and a
non-polarized sidewall portion adjacent to and in communication
with the cathodically polarized sidewall portion, wherein the
non-polarized sidewall portion is located adjacent to and in
communication with the bath-air interface, wherein the
non-polarized sidewall comprises a thermal conductor adjacent to
the cathodically polarized sidewall portion and in communication
with the bath-air interface, wherein the thermal conductor is
configured to transfer heat from the molten electrolyte bath
wherein, via the thermal conductor, a frozen ledge is defined along
the thermal conductor portion of the sidewall.
[0079] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body configured to retain a molten
electrolyte bath, wherein the cell body comprises: at least one
sidewall and a bottom; wherein the sidewall comprises: a
cathodically polarized sidewall portion in liquid communication
with the electrolyte bath, wherein the cathodically polarized
sidewall is positioned adjacent to and in communication with the
bottom of the cell body (e.g. across the bath-metal interface, in
communication with the metal pad); and a non-polarized sidewall
portion adjacent to and in communication with the cathodically
polarized sidewall portion, wherein the non-polarized sidewall
portion is located adjacent to and in communication with the
bath-air interface, wherein the non-polarized sidewall comprises a
thermal conductor adjacent to the cathodically polarized sidewall
portion and in communication with the bath-air interface, wherein
the thermal conductor is configured to transfer heat from the
molten electrolyte bath wherein, via the thermal conductor, a
frozen ledge is defined along the thermal conductor portion of the
sidewall.
[0080] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; an electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion, configured to fit
onto a thermal insulation package of the sidewall and retain the
electrolyte, the first sidewall portion comprising non-polarized
sidewall portion; and a second sidewall portion comprising a
cathodically polarized sidewall, the 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 (e.g. metal pad).
[0081] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion, configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte, the first sidewall portion
comprising non-polarized sidewall portion; and a second sidewall
portion comprising a cathodically polarized sidewall, the 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 (e.g. metal
pad).
[0082] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; an electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion, configured to fit
onto a thermal insulation package of the sidewall and retain the
electrolyte, the first sidewall portion comprising a non-polarized
sidewall portion; and a second sidewall portion comprising a
cathodically polarized sidewall, the 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 bottom of the cell body (e.g. metal pad); and a
directing member, wherein the directing member is positioned
between the second sidewall portion (e.g. cathodic sidewall
portion) and the first sidewall portion (e.g. non-polarized
sidewall portion), further wherein the directing member is
laterally spaced above the base of the trough, such that the
directing member is configured to direct the protecting deposit
into the trough.
[0083] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion, configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte, the first sidewall portion
comprising a non-polarized sidewall portion; and a second sidewall
portion comprising a cathodically polarized sidewall, the 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 bottom of the cell body
(e.g. metal pad); and a directing member, wherein the directing
member is positioned between the second sidewall portion (e.g.
cathodic sidewall portion) and the first sidewall portion (e.g.
non-polarized sidewall portion), further wherein the directing
member is laterally spaced above the base of the trough, such that
the directing member is configured to direct the protecting deposit
into the trough.
[0084] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; an electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion, configured to fit
onto a thermal insulation package of the sidewall and retain the
electrolyte, the first sidewall portion comprising a non-polarized
sidewall portion; and a second sidewall portion comprising a
cathodically polarized sidewall, the 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 and the
second sidewall portion define a gap; and a thermal conductor
configured to fit in the gap and extend between the first sidewall
portion and the second sidewall portion; wherein thermal conductor
is configured to transfer heat from the molten electrolyte bath to
define via the thermal conductor, a frozen ledge between the first
sidewall portion and the second sidewall portion along the thermal
conductor.
[0085] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain the molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion, configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte, the first sidewall portion
comprising a non-polarized sidewall portion; and a second sidewall
portion comprising a cathodically polarized sidewall, the 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 and the second sidewall portion define a gap; and
a thermal conductor configured to fit in the gap and extend between
the first sidewall portion and the second sidewall portion; wherein
thermal conductor is configured to transfer heat from the molten
electrolyte bath to define via the thermal conductor, a frozen
ledge between the first sidewall portion and the second sidewall
portion along the thermal conductor.
[0086] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion, configured to fit
onto a thermal insulation package of the sidewall and retain the
electrolyte, the first sidewall portion comprising a non-polarized
sidewall portion; a second sidewall portion comprising a
cathodically polarized sidewall, the 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 and the
second sidewall portion define a gap; and a frozen ledge device
configured to fit in the gap between the first sidewall portion and
the second sidewall portion, wherein via the frozen ledge device,
heat is extracted from the molten salt bath adjacent to the frozen
ledge device to define a frozen ledge along a portion of the
sidewall between the first sidewall portion and the second sidewall
portion.
[0087] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion, configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte, the first sidewall portion
comprising a non-polarized sidewall portion; a second sidewall
portion comprising a cathodically polarized sidewall, the 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 and the second sidewall portion define a gap; and
a frozen ledge device configured to fit in the gap between the
first sidewall portion and the second sidewall portion, wherein via
the frozen ledge device, heat is extracted from the molten salt
bath adjacent to the frozen ledge device to define a frozen ledge
along a portion of the sidewall between the first sidewall portion
and the second sidewall portion.
[0088] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
sidewall comprises: an anodically polarized sidewall portion
positioned at or above the metal pad-to-bath interface; a
cathodically polarized sidewall portion positioned at or below the
metal-to-bath interface; and a portion of non-polarized sidewall
portion extending between the anodically polarized sidewall portion
and the cathodically polarized sidewall portion, wherein the
non-polarized sidewall portion comprises an insulator configured to
electrically insulate the anodic sidewall from the cathodic
sidewall.
[0089] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body configured to retain a molten
electrolyte bath, wherein the cell body comprises: at least one
sidewall and a bottom; wherein the sidewall comprises: an
anodically polarized sidewall portion positioned at or above the
metal pad-to-bath interface; a cathodically polarized sidewall
portion positioned at or below the metal-to-bath interface; and a
portion of non-polarized sidewall portion extending between the
anodically polarized sidewall portion and the cathodically
polarized sidewall portion, wherein the non-polarized sidewall
portion comprises an insulator configured to electrically insulate
the anodic sidewall from the cathodic sidewall.
[0090] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
side comprises: an anodically polarized sidewall portion positioned
across the vapor-to-bath interface; a cathodically polarized
sidewall portion positioned below the vapor-to-bath interface (e.g.
at the bath-to-metal interface); and a non-polarized sidewall
portion extending between the anodically polarized sidewall portion
and the cathodically polarized sidewall portion, wherein the
non-polarized sidewall portion comprises an insulator.
[0091] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body configured to retain a molten
electrolyte bath, wherein the cell body comprises: at least one
sidewall and a bottom; wherein the side comprises: an anodically
polarized sidewall portion positioned across the vapor-to-bath
interface; a cathodically polarized sidewall portion positioned
below the vapor-to-bath interface (e.g. at the bath-to-metal
interface); and a non-polarized sidewall portion extending between
the anodically polarized sidewall portion and the cathodically
polarized sidewall portion, wherein the non-polarized sidewall
portion comprises an insulator.
[0092] In one aspect of the instant disclosure, an electrolysis
cell assembly is provided, comprising: an anode; a cathode in
spaced relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
side comprises: an anodically polarized sidewall portion positioned
across the vapor-to-bath interface; a cathodically polarized
sidewall portion positioned below the vapor-to-bath interface (e.g.
at the bath-to-metal interface); and a non-polarized sidewall
portion comprising a thermal conductor, wherein the thermal
conductor is configured to extend between the anodically polarized
sidewall portion and the cathodically polarized sidewall portion,
wherein the thermal conductor is configured to transfer heat from
the molten electrolyte bath wherein via the thermal conductor, a
frozen ledge is formed between the anodically polarized sidewall
and the cathodically polarized sidewall, adjacent to and along the
surface of the thermal conductor.
[0093] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body configured to retain a molten
electrolyte bath, wherein the cell body comprises: at least one
sidewall and a bottom; wherein the side comprises: an anodically
polarized sidewall portion positioned across the vapor-to-bath
interface; a cathodically polarized sidewall portion positioned
below the vapor-to-bath interface (e.g. at the bath-to-metal
interface); and a non-polarized sidewall portion comprising a
thermal conductor, wherein the thermal conductor is configured to
extend between the anodically polarized sidewall portion and the
cathodically polarized sidewall portion, wherein the thermal
conductor is configured to transfer heat from the molten
electrolyte bath wherein via the thermal conductor, a frozen ledge
is formed between the anodically polarized sidewall and the
cathodically polarized sidewall, adjacent to and along the surface
of the thermal conductor.
[0094] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
side comprises: an anodically polarized sidewall portion positioned
across the vapor-to-bath interface; a cathodically polarized
sidewall portion positioned below the vapor-to-bath interface (e.g.
at the bath-to-metal interface); and a non-polarized sidewall
portion extending between the anodically polarized sidewall portion
and the cathodically polarized sidewall portion, wherein the
non-polarized sidewall comprises a frozen ledge device, wherein,
via the frozen ledge device, heat is extracted from the molten
electrolyte bath (e.g. adjacent to the frozen ledge device)
wherein, via the frozen ledge device, a frozen ledge is defined
between the anodically polarized sidewall portion and the
cathodically polarized sidewall portion.
[0095] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body configured to retain a molten
electrolyte bath, wherein the cell body comprises: at least one
sidewall and a bottom; wherein the side comprises: an anodically
polarized sidewall portion positioned across the vapor-to-bath
interface; a cathodically polarized sidewall portion positioned
below the vapor-to-bath interface (e.g. at the bath-to-metal
interface); and a non-polarized sidewall portion extending between
the anodically polarized sidewall portion and the cathodically
polarized sidewall portion, wherein the non-polarized sidewall
comprises a frozen ledge device, wherein, via the frozen ledge
device, heat is extracted from the molten electrolyte bath (e.g.
adjacent to the frozen ledge device) wherein, via the frozen ledge
device, a frozen ledge is defined between the anodically polarized
sidewall portion and the cathodically polarized sidewall
portion.
[0096] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body
configured to retain the molten electrolyte bath, wherein the cell
body comprises: at least one sidewall and a bottom; wherein the
side comprises: an anodically polarized sidewall portion positioned
across the vapor-to-bath interface; a cathodically polarized
sidewall portion positioned below the vapor-to-bath interface (e.g.
at the bath-to-metal interface); and a non-polarized sidewall
portion extending between the anodically polarized sidewall portion
and the cathodically polarized sidewall portion, wherein the
non-polarized sidewall comprises a non-reactive sidewall material
which is a component of the bath chemistry, further wherein, via
the bath chemistry and percent saturation of the non-reactive
material in the bath, the non-reactive sidewall material is
substantially non-reactive with the molten salt electrolyte (e.g.
during cell operation).
[0097] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body configured to retain a molten
electrolyte bath, wherein the cell body comprises: at least one
sidewall and a bottom; wherein the side comprises: an anodically
polarized sidewall portion positioned across the air-to-bath
interface; a cathodically polarized sidewall portion positioned
below the air-to-bath interface (e.g. at the bath-to-metal
interface); and a non-polarized sidewall portion extending between
the anodically polarized sidewall portion and the cathodically
polarized sidewall portion, wherein the non-polarized sidewall
comprises a non-reactive sidewall material which is a component of
the bath chemistry, further wherein, via the bath chemistry and
percent saturation of the non-reactive material in the bath, the
non-reactive sidewall material is substantially non-reactive with
the molten salt electrolyte (e.g. during cell operation).
[0098] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; an electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion comprising an anodic
sidewall, wherein the anodic sidewall is configured to fit onto a
thermal insulation package of the sidewall and retain the
electrolyte; a second sidewall portion comprising a cathodic
sidewall, the cathodic sidewall configured to extend up from the
bottom of the cell body, wherein the cathodic sidewall is
longitudinally spaced from the anodic sidewall, such that the
anodic sidewall and the cathodic sidewall define a gap there
between; and a non-polarized portion comprising an insulator
located in the gap and extending between the anodic sidewall and
the cathodic sidewall, wherein the insulator is configured to
electrically insulate the anodic sidewall from the cathodic
sidewall.
[0099] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion comprising an anodic sidewall, wherein the anodic sidewall
is configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte; a second sidewall portion
comprising a cathodic sidewall, the cathodic sidewall configured to
extend up from the bottom of the cell body, wherein the cathodic
sidewall is longitudinally spaced from the anodic sidewall, such
that the anodic sidewall and the cathodic sidewall define a gap
there between; and a non-polarized portion comprising an insulator
located in the gap and extending between the anodic sidewall and
the cathodic sidewall, wherein the insulator is configured to
electrically insulate the anodic sidewall from the cathodic
sidewall.
[0100] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion comprising an anodic
sidewall, wherein the anodic sidewall is configured to fit onto a
thermal insulation package of the sidewall and retain the
electrolyte; and a second sidewall portion comprising a cathodic
sidewall, the cathodic sidewall configured to extend up from the
bottom of the cell body, wherein the cathodic sidewall is
longitudinally spaced from the anodic sidewall, such that the
anodic sidewall, the cathodic sidewall, and a base between the
anodic sidewall and the cathodic sidewall define a trough; wherein
the trough is configured to receive a protecting deposit and retain
the protecting deposit separately from the cell bottom (e.g. metal
pad).
[0101] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion comprising an anodic sidewall, wherein the anodic sidewall
is configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte; and a second sidewall portion
comprising a cathodic sidewall, the cathodic sidewall configured to
extend up from the bottom of the cell body, wherein the cathodic
sidewall is longitudinally spaced from the anodic sidewall, such
that the anodic sidewall, the cathodic sidewall, and a base between
the anodic sidewall and the cathodic sidewall define a trough;
wherein the trough is configured to receive a protecting deposit
and retain the protecting deposit separately from the cell bottom
(e.g. metal pad).
[0102] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion comprising an anodic
sidewall, wherein the anodic sidewall is configured to fit onto a
thermal insulation package of the sidewall and retain the
electrolyte; and a second sidewall portion comprising a cathodic
sidewall, the cathodic sidewall configured to extend up from the
bottom of the cell body, wherein the cathodic sidewall is
longitudinally spaced from the anodic sidewall, such that the
anodic sidewall, the cathodic sidewall, and a base between the
anodic sidewall and the cathodic sidewall define a trough; wherein
the trough is configured to receive a protecting deposit and retain
the protecting deposit separately from the cell bottom (e.g. metal
pad); and a directing member, wherein the directing member is
positioned between the cathodic sidewall and the anodic sidewall,
further wherein the directing member is laterally spaced above the
base of the such that the directing member is configured to direct
the protecting deposit into the trough.
[0103] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain the molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion comprising an anodic sidewall, wherein the anodic sidewall
is configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte; and a second sidewall portion
comprising a cathodic sidewall, the cathodic sidewall configured to
extend up from the bottom of the cell body, wherein the cathodic
sidewall is longitudinally spaced from the anodic sidewall, such
that the anodic sidewall, the cathodic sidewall, and a base between
the anodic sidewall and the cathodic sidewall define a trough;
wherein the trough is configured to receive a protecting deposit
and retain the protecting deposit separately from the cell bottom
(e.g. metal pad); and a directing member, wherein the directing
member is positioned between the cathodic sidewall and the anodic
sidewall, further wherein the directing member is laterally spaced
above the base of the such that the directing member is configured
to direct the protecting deposit into the trough.
[0104] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion comprising an anodic
sidewall, wherein the anodic sidewall is configured to fit onto a
thermal insulation package of the sidewall and retain the
electrolyte; and a second sidewall portion comprising a cathodic
sidewall, the cathodic sidewall configured to extend up from the
bottom of the cell body, wherein the cathodic sidewall is
longitudinally spaced from the anodic sidewall, such that the
anodic sidewall and the cathodic sidewall define a gap there
between; and a non-polarized portion comprising a frozen ledge
device located in the gap and extending between the anodic sidewall
and the cathodic sidewall, wherein the frozen ledge device is
configured to fit in the gap between the anodic sidewall and the
cathodic sidewall, wherein via the frozen ledge device, heat is
extracted from the molten salt bath to define a frozen ledge along
the gap between the first sidewall portion and the second sidewall
portion.
[0105] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion comprising an anodic sidewall, wherein the anodic sidewall
is configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte; and a second sidewall portion
comprising a cathodic sidewall, the cathodic sidewall configured to
extend up from the bottom of the cell body, wherein the cathodic
sidewall is longitudinally spaced from the anodic sidewall, such
that the anodic sidewall and the cathodic sidewall define a gap
there between; and a non-polarized portion comprising a frozen
ledge device located in the gap and extending between the anodic
sidewall and the cathodic sidewall, wherein the frozen ledge device
is configured to fit in the gap between the anodic sidewall and the
cathodic sidewall, wherein via the frozen ledge device, heat is
extracted from the molten salt bath to define a frozen ledge along
the gap between the first sidewall portion and the second sidewall
portion.
[0106] In one aspect of the instant disclosure, an electrolysis
cell is provided, comprising: an anode; a cathode in spaced
relation from the anode; a molten electrolyte bath in liquid
communication with the anode and the cathode; a cell body having a
bottom and at least one sidewall, wherein the cell body is
configured to retain the molten electrolyte bath, wherein the
sidewall comprises: a first sidewall portion comprising an anodic
sidewall, wherein the anodic sidewall is configured to fit onto a
thermal insulation package of the sidewall and retain the
electrolyte; and a second sidewall portion comprising a cathodic
sidewall, the cathodic sidewall configured to extend up from the
bottom of the cell body, wherein the cathodic sidewall is
longitudinally spaced from the anodic sidewall, such that the
anodic sidewall and the cathodic sidewall define a gap there
between; and a non-polarized portion comprising a thermal
conductor, wherein the thermal conductor is configured to fit in
the gap between the anodic sidewall and the cathodic sidewall,
wherein via the thermal conductor, heat is extracted from the
molten salt bath adjacent to the thermal conductor to define a
frozen ledge along the gap between the anodic sidewall and the
cathodic sidewall.
[0107] In one aspect of the instant disclosure, an assembly is
provided, comprising: a cell body having a bottom and at least one
sidewall, wherein the cell body is configured to retain a molten
electrolyte bath, wherein the sidewall comprises: a first sidewall
portion comprising an anodic sidewall, wherein the anodic sidewall
is configured to fit onto a thermal insulation package of the
sidewall and retain the electrolyte; and a second sidewall portion
comprising a cathodic sidewall, the cathodic sidewall configured to
extend up from the bottom of the cell body, wherein the cathodic
sidewall is longitudinally spaced from the anodic sidewall, such
that the anodic sidewall and the cathodic sidewall define a gap
there between; and a non-polarized portion comprising a thermal
conductor, wherein the thermal conductor is configured to fit in
the gap between the anodic sidewall and the cathodic sidewall,
wherein via the thermal conductor, heat is extracted from the
molten salt bath adjacent to the thermal conductor to define a
frozen ledge along the gap between the anodic sidewall and the
cathodic sidewall.
[0108] In some embodiments, the bath comprises a feed material
(e.g. alumina) at a content above its saturation limit (e.g. such
that there is particulate present in the bath).
[0109] In some embodiments, the bath component (e.g. alumina)
comprises an average bath content of: within about 2% of
saturation; within about 1.5% of saturation; within about 1% of
saturation; within about 0.5% of saturation; at saturation; or
above saturation (e.g. undissolved particulate of the bath
component is present in the bath).
[0110] In some embodiments, the saturation of the bath component
is: at least about 95% of saturation; at least about 96% of
saturation; at least about 97% of saturation; at least about 98% of
saturation; at least about 99% of saturation; at 100% of
saturation; or above saturation (e.g. undissolved particulate of
the bath component is present in the bath).
[0111] In some embodiments, the saturation of the bath component
is: not greater than about 95% of saturation; not greater than
about 96% of saturation; not greater than about 97% of saturation;
not greater than about 98% of saturation; not greater than about
99% of saturation; or not greater than 100% of saturation.
[0112] In some embodiments, the sidewall constituent comprises a
percentage of saturation above a certain threshold of saturation in
the electrolyte bath (e.g. with cell operating parameters).
[0113] In some embodiments (e.g. where the sidewall constituent is
alumina), alumina saturation (i.e. average saturation %) is
analytically determined via a LECO analysis. In some embodiments,
(i.e. where the sidewall constituent is other than alumina, e.g.
Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, Y, La, and Ce), the
average saturation % is quantified by AA, ICP, XRF, and/or
combinations thereof, along with other commonly accepted analytical
methodologies. In some embodiments, the analytical methods of
determining the saturation % of stable material includes a
calibration error associated with the analytical method (e.g. LECO
measurement has an error rate of generally +/-5%).
[0114] In some embodiments, the sidewall constituent is at present
in the bath at an average % saturation content of: at least 70% of
saturation; at least 75% of saturation; at least 80% of saturation;
at least 85% of saturation; at least 90% of saturation, at least
95% of saturation, at least 100% of saturation (i.e. saturated); or
at least 105% of saturation (i.e. above saturation).
[0115] In some embodiments, the sidewall constituent is at present
in the bath at an average % saturation content of: not greater than
70% of saturation; not greater than 75% of saturation; 80% of
saturation; not greater than 85% of saturation; not greater than
90% of saturation, not greater than 95% of saturation, not greater
than 100% of saturation (i.e. saturated); or not greater than 105%
of saturation (i.e. above saturation).
[0116] In some embodiments, the bath component comprises a bath
content saturation percentage measured as an average throughout the
cell. In some embodiments, the bath component comprises a bath
content saturation percentage measured at a location adjacent to
the sidewall (e.g. non-reactive/stable sidewall material).
[0117] In some embodiments, the location adjacent to the sidewall
is the bath: touching the wall; not greater than about 1'' from the
wall; not greater than about 2'' from the wall, not greater than
about 4'' from the wall; not greater than about 6'' from the wall;
not greater than about 8'' from the wall; not greater than about
10'' from the wall; not greater than about 12'' from the wall; not
greater than about 14'' from the wall; not greater than about 16''
from the wall; not greater than about 18'' from the wall; not
greater than about 20'' from the wall; not greater than about 22''
from the wall, or not greater than about 24'' from the wall.
[0118] In some embodiments, the location adjacent to the sidewall
is the bath: touching the wall; less than about 1'' from the wall;
less than about 2'' from the wall, less than about 4'' from the
wall; less than about 6'' from the wall; less than about 8'' from
the wall; less than about 10'' from the wall; less than about 12''
from the wall; less than about 14'' from the wall; less than about
16'' from the wall; less than about 18'' from the wall; less than
about 20'' from the wall; less than about 22'' from the wall, or
less than about 24'' from the wall.
[0119] In some embodiments, the protecting deposit comprises the at
least one bath component. In some embodiments, the protecting
deposit comprises at least two bath components.
[0120] In some embodiments, the protecting deposit extends from the
trough and up to at least an upper surface of the electrolyte
bath.
[0121] In some embodiments, the directing member is constructed of
a material which is present in the bath chemistry, such that via
the bath chemistry, the directing member is maintained in the
molten salt electrolyte. In some embodiments, the directing member
is composed of a stable material (e.g. non-reactive material in the
bath and/or vapor phase).
[0122] In some embodiments, the base of the trough is defined by a
feed block, wherein the feed block is 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. In some embodiments, the feed block comprises a stable
material (non-reactive material). In some embodiments, the feed
block comprises alumina.
[0123] In some embodiments, the cell further comprises a feeder
(e.g. feed device) configured to provide the protecting deposit in
the trough.
[0124] In some embodiments, the feed device is attached to the cell
body.
[0125] In one aspect of the instant disclosure, a method is
provided, comprising: passing current from an anode through a
molten electrolyte bath to a cathode in an electrolysis cell;
feeding a feed material into the electrolysis cell at a location
adjacent to a cell wall, such that the feed material is retained in
a trough defined adjacent to the sidewall; and via the feeding
step, maintaining the sidewall in the molten electrolyte during
cell operation, wherein the sidewall is constructed of at least one
component which is within about 95% of saturation in the molten
electrolyte bath.
[0126] In some embodiments, the method includes: concomitant to the
first step, maintaining the bath at a temperature not exceeding
980.degree. C., wherein the sidewalls of the cells are
substantially free of a frozen ledge.
[0127] In some embodiments, the method includes consuming the
protecting deposit to supply metal ions to the electrolyte
bath.
[0128] In some embodiments, the method includes producing a metal
product from the at least one bath component.
[0129] Various ones of the inventive aspects noted hereinabove may
be combined to yield apparatuses, assemblies, and methods related
to primary metal production in electrolytic cells at low
temperature (e.g. below 980.degree. C.).
[0130] These and other aspects, advantages, and novel features of
the invention are set forth in part in the description that follows
and will become apparent to those skilled in the art upon
examination of the following description and figures, or may be
learned by practicing the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0131] FIG. 1 depicts a partial cut-away side view of a cell body
having an anodic sidewall and a non-polarized sidewall in
accordance with the instant disclosure.
[0132] FIG. 2 depicts a partial cut-away side view of a cell body
having an anodic sidewall and a non-polarized sidewall (thermal
conductor with frozen ledge) in accordance with the instant
disclosure.
[0133] FIG. 3A depicts a partial cut-away side view of a cell body
having an anodic sidewall and a non-polarized sidewall (stable
sidewall/non-reactive material) in accordance with the instant
disclosure.
[0134] FIG. 3B depicts a partial cut-away side view of a cell body
having an anodic sidewall and a non-polarized sidewall (stable
sidewall in a stepped/extended configuration) in accordance with
the instant disclosure.
[0135] FIG. 3C depicts a partial cut-away side view of a cell body
having an anodic sidewall and a non-polarized sidewall (stable
sidewall in a stepped/extended configuration) having a feeder
providing a protecting deposit to the non-polarized sidewall, in
accordance with the instant disclosure.
[0136] FIG. 3D depicts another embodiment of a partial cut-away
side view of a cell body having an anodic sidewall and a
non-polarized sidewall (stable sidewall in a stepped/extended
configuration) having a feeder providing a protecting deposit to
the non-polarized sidewall, in accordance with the instant
disclosure.
[0137] FIG. 3E depicts a partial cut-away side view of a cell body
having an anodic sidewall and second sidewall portion including a
non-polarized sidewall (stable sidewall in a stepped/extended
configuration).
[0138] FIG. 3F depicts another embodiment of a partial cut-away
side view of a cell body having an anodic sidewall and second
sidewall portion including a non-polarized sidewall (stable
sidewall in a stepped/extended configuration).
[0139] FIG. 4 depicts a partial cut-away side view of a cell body
having an anodic sidewall and a non-polarized sidewall (frozen
ledge device with a frozen ledge) in accordance with the instant
disclosure.
[0140] FIG. 5 depicts a partial cut-away side view of a cell body
having an anodic sidewall and a second sidewall portion which is a
non-polarized sidewall (stable material), including a feeder
providing a protecting deposit, in accordance with the instant
disclosure.
[0141] FIG. 6 depicts a partial cut-away side view of a cell body
having an anodic sidewall and a second sidewall portion which is a
non-polarized sidewall (stable material), including a feeder
providing a protecting deposit and a directing member, in
accordance with the instant disclosure.
[0142] FIG. 7 depicts a partial cut-away side view of a cell body
having an anodic sidewall and a second sidewall portion which is a
non-polarized sidewall (stable material), including a thermal
conductor material which provides a frozen ledge between the first
sidewall portion and the second sidewall portion, in accordance
with the instant disclosure.
[0143] FIG. 8 depicts a partial cut-away side view of a cell body
having an anodic sidewall and a second sidewall portion which is a
non-polarized sidewall (stable material), including a frozen ledge
device which provides a frozen ledge between the first sidewall
portion and the second sidewall portion, in accordance with the
instant disclosure.
[0144] FIG. 9 depicts a partial cut-away side view of a cell body
having a cathodic sidewall and a non-polarized sidewall in
accordance with the instant disclosure.
[0145] FIG. 10A depicts a partial cut-away side view of a cell body
having a cathodic sidewall and a non-polarized sidewall (stable
sidewall/non-reactive material) in accordance with the instant
disclosure.
[0146] FIG. 10B depicts another embodiment of a partial cut-away
side view of a cell body having a cathodic sidewall and a
non-polarized sidewall, in accordance with the instant
disclosure.
[0147] FIG. 10C depicts another embodiment of a partial cut-away
side view of a cell body having a first sidewall portion which is a
non-polarized sidewall (stable sidewall) and a second sidewall
portion which is a cathodic sidewall, in accordance with the
instant disclosure.
[0148] FIG. 10D depicts another embodiment of a partial cut-away
side view of a cell body having a first sidewall portion which is a
non-polarized sidewall (stable sidewall) and a second sidewall
portion which is a cathodic sidewall, including a feeder which
provides a protecting deposit, in accordance with the instant
disclosure.
[0149] FIG. 11 depicts a partial cut-away side view of a cell body
having a cathodic sidewall and a non-polarized sidewall (frozen
ledge device with a frozen ledge in accordance with the instant
disclosure.
[0150] FIG. 12 depicts a partial cut-away side view of a cell body
having a cathodic sidewall and a non-polarized sidewall (thermal
conductor with a frozen ledge) in accordance with the instant
disclosure.
[0151] FIG. 13 depicts a partial cut-away side view of a cell body
having a first sidewall portion (stable sidewall) and a second
sidewall portion (cathodic sidewall) with a feeder and a protecting
deposit in accordance with the instant disclosure.
[0152] FIG. 14 depicts a partial cut-away side view of a cell body
having a first sidewall portion (stable sidewall) and a second
sidewall portion (cathodic sidewall) with a feeder and a protecting
deposit, including a directing member in accordance with the
instant disclosure.
[0153] FIG. 15 depicts a partial cut-away side view of a cell body
having a first sidewall portion (stable sidewall) and a second
sidewall portion (cathodic sidewall) with a thermal conductor there
between defining a frozen ledge, in accordance with the instant
disclosure.
[0154] FIG. 16 depicts a partial cut-away side view of a cell body
having a first sidewall portion (stable sidewall) and a second
sidewall portion (cathodic sidewall) with a frozen ledge device
defining a frozen ledge, in accordance with the instant
disclosure.
[0155] FIG. 17 depicts a partial cut-away side view of a cell body
having a sidewall which includes an anodic sidewall portion, a
cathodic sidewall portion, and an insulator (e.g. electrical
insulator between the anodic and cathodic sidewall portions), in
accordance with the instant disclosure.
[0156] FIG. 18 depicts a partial cut-away side view of a cell body
having a sidewall which includes an anodic sidewall portion, a
cathodic sidewall portion, and an electrical insulator (thermal
conductor material with frozen ledge) between the anodic and
cathodic sidewall portions), in accordance with the instant
disclosure.
[0157] FIG. 19 depicts a partial cut-away side view of a cell body
having a sidewall which includes an anodic sidewall portion, a
cathodic sidewall portion, and an electrical insulator (frozen
ledge device with a frozen ledge) between the anodic and cathodic
sidewall portions), in accordance with the instant disclosure.
[0158] FIG. 20 depicts a partial cut-away side view of a cell body
having a sidewall which includes an anodic sidewall portion, a
cathodic sidewall portion, and an electrical insulator (stable
sidewall material/non-reactive material) between the anodic and
cathodic sidewall portions), in accordance with the instant
disclosure.
[0159] FIG. 21 depicts a partial cut-away side view of a cell body
having a first sidewall portion which is anodic and a second
sidewall portion which is cathodic, with an electrical insulator
spanning the distance between the first sidewall portion and the
second sidewall portion, in accordance with the instant
disclosure.
[0160] FIG. 22 depicts a partial cut-away side view of a cell body
having a first sidewall portion which is anodic and a second
sidewall portion which is cathodic, with an electrical insulator
(protecting deposit provided via feeder) spanning the distance
between the first sidewall portion and the second sidewall portion,
in accordance with the instant disclosure.
[0161] FIG. 23 depicts a partial cut-away side view of a cell body
having a first sidewall portion which is anodic and a second
sidewall portion which is cathodic, with an electrical insulator
(protecting deposit provided via feeder) spanning the distance
between the first sidewall portion and the second sidewall portion
including a directing member, in accordance with the instant
disclosure.
[0162] FIG. 24 depicts a partial cut-away side view of a cell body
having a first sidewall portion which is anodic and a second
sidewall portion which is cathodic, with an electrical insulator
(frozen ledge device with frozen ledge) spanning the distance
between the first sidewall portion and the second sidewall portion
including a directing member, in accordance with the instant
disclosure.
[0163] FIG. 25 depicts a partial cut-away side view of a cell body
having a first sidewall portion which is anodic and a second
sidewall portion which is cathodic, with an electrical insulator
(frozen ledge device with frozen ledge) spanning the distance
between the first sidewall portion and the second sidewall portion
including a directing member, in accordance with the instant
disclosure.
[0164] FIG. 26 depicts a schematic side view of an electrolysis
cell in operation in accordance with the instant disclosure,
depicting an active sidewall (e.g. one or more sidewalls of the
instant disclosure).
[0165] FIG. 27 is a chart depicting the alumina dissolution rate
(m/s) in electrolytic bath per percent alumina saturation, plotted
at five (5) different temperature lines (750.degree. C.,
800.degree. C., 850.degree. C., 900.degree. C., and 950.degree.
C.).
[0166] FIG. 28 is a chart of temperature and heat flux of the bath,
coolant, and outlet ledge as a function of time.
[0167] FIG. 29 depicts a schematic cut-away side view of a frozen
ledge device (removable/adjustable) in accordance with the instant
disclosure.
[0168] FIG. 30 depicts a schematic cut-away side view of a frozen
ledge device which is configured to be retained at least partly
through the sidewall, in accordance with the instant
disclosure.
[0169] FIG. 31 depicts a partial cut away side view of a cell with
a rotary feeder, in accordance with the Examples section.
[0170] FIG. 32 depicts a partial cut away side view of a cell
having an anodic sidewall portion and a cathodic sidewall portion
with a protecting deposit there between, in accordance with one of
the experiments run for the Examples section.
[0171] FIGS. 33A-H depicts a partial cut away side view of various
angles of the protecting deposit and the trough bottom/base
(sometimes called a feed block) beneath the protecting deposit.
Various angles of the protecting deposit are depicted (angling
towards the second sidewall portion, angled towards the first
sidewall portion, flat, angled, and the like). Also, various angles
of the trough bottom/base are depicted (angling towards the second
sidewall portion, angled towards the first sidewall portion, flat,
angled, and the like).
[0172] FIGS. 34A-D depicts a partial cut-away side view of the
various configurations of the shelf top and/or second sidewall
portion. FIG. 34A depicts a transverse configuration, angled
towards the center of the cell (to promote cell drain). FIG. 34B
depicts a transverse configuration, angled towards the sidewall (to
promote retention of the feed material in the protecting deposit).
FIG. 34C depicts an angled configuration (e.g. pointed). FIG. 34D
depicts a curved, or arcuate upper most region of the shelf or
second sidewall portion.
[0173] FIG. 35 depicts a schematic cut away side view of a
transverse sidewall portion (e.g. sloped anodically polarized
sidewall, depicted with feed device, trough, and second sidewall
portion.
[0174] FIG. 36 depicts a schematic cut away side view of a
cathodically polarized sidewall of the present disclosure, wherein
the cathodically polarized sidewall extends through the bath-metal
interface and the bath-vapor (sometimes called air) interface.
DETAILED DESCRIPTION
[0175] Reference will now be made in detail to the accompanying
drawings, which at least assist in illustrating various pertinent
embodiments of the present invention.
[0176] As used herein, "electrolysis" means any process that brings
about a chemical reaction by passing electric current through a
material. In some embodiments, electrolysis occurs where a species
of metal is reduced in an electrolysis cell to produce a metal
product. Some non-limiting examples of electrolysis include primary
metal production. Some non-limiting examples of electrolytically
produced metals include: rare earth metals, non-ferrous metals
(e.g. copper, nickel, zinc, magnesium, lead, titanium, aluminum,
and rare earth metals).
[0177] As used herein, "electrolysis cell" means a device for
producing electrolysis. In some embodiments, the electrolysis cell
includes a smelting pot, or a line of smelters (e.g. multiple
pots). In one non-limiting example, the electrolysis cell is fitted
with electrodes, which act as a conductor, through which a current
enters or leaves a nonmetallic medium (e.g. electrolyte bath).
[0178] As used herein, "electrode" means positively charged
electrodes (e.g. anodes) or negatively charged electrodes (e.g.
cathodes).
[0179] As used herein, "anode" means the positive electrode (or
terminal) by which current enters an electrolytic cell. In some
embodiments, the anodes are constructed of electrically conductive
materials. Some non-limiting examples of anode materials include:
metals, metal alloys, oxides, ceramics, cermets, carbon, and
combinations thereof.
[0180] As used herein, "anode assembly" includes one or more
anode(s) connected with, a support. In some embodiments, the anode
assembly includes: the anodes, the support (e.g. refractory block
and other bath resistant materials), and the electrical bus
work.
[0181] As used herein, "support" means a member that maintains
another object(s) in place. In some embodiments, the support is the
structure that retains the anode(s) in place. In one embodiment,
the support facilitates the electrical connection of the electrical
bus work to the anode(s). In one embodiment, the support is
constructed of a material that is resistant to attack from the
corrosive bath. For example, the support is constructed of
insulating material, including, for example refractory material. In
some embodiments, multiple anodes are connected (e.g. mechanically
and electrically) to the support (e.g. removably attached), which
is adjustable and can be raised, lowered, or otherwise moved in the
cell.
[0182] As used herein, "electrical bus work" refers to the
electrical connectors of one or more component. For example, the
anode, cathode, and/or other cell components can have electrical
bus work to connect the components together. In some embodiments,
the electrical bus work includes pin connectors in the anodes, the
wiring to connect the anodes and/or cathodes, electrical circuits
for (or between) various cell components, and combinations
thereof.
[0183] As used herein, "cathode" means the negative electrode or
terminal by which current leaves an electrolytic cell. In some
embodiments, the cathodes are constructed of an electrically
conductive material. Some non-limiting examples of the cathode
material include: carbon, cermet, ceramic material(s), metallic
material(s), and combinations thereof. In one embodiment, the
cathode is constructed of a transition metal boride compound, for
example TiB.sub.2. In some embodiments, the cathode is electrically
connected through the bottom of the cell (e.g. current collector
bar and electrical buswork). As some non-limiting examples,
cathodes and/or cathodically polarized sidewall portions are
constructed of: TiB.sub.2, TiB.sub.2--C composite materials, boron
nitride, zirconium borides, hafnium borides, graphite, and
combinations thereof.
[0184] As used herein, "cathode assembly" refers to the cathode
(e.g. cathode block), the current collector bar, the electrical bus
work, and combinations thereof.
[0185] As used herein "current collector bar" refers to a bar that
collects current from the cell. In one non-limiting example, the
current collector bar collects current from the cathode and
transfers the current to the electrical buswork to remove the
current from the system.
[0186] As used herein, "electrolyte bath" refers to a liquefied
bath having at least one species of metal to be reduced (e.g. via
an electrolysis process). A non-limiting example of the
electrolytic bath composition includes: NaF--AlF.sub.3 (in an
aluminum electrolysis cell), NaF, AlF.sub.3, CaF.sub.2, MgF.sub.2,
LiF, KF, and combinations thereof--with dissolved alumina.
[0187] As used herein, "molten" means in a flowable form (e.g.
liquid) through the application of heat. As a non-limiting example,
the electrolytic bath is in molten form (e.g. at least about
750.degree. C.). As another example, the metal product that forms
at the bottom of the cell (e.g. sometimes called a "metal pad") is
in molten form.
[0188] In some embodiments, the molten electrolyte bath/cell
operating temperature is: at least about 750.degree. C.; at least
about 800.degree. C.; at least about 850.degree. C.; at least about
900.degree. C.; at least about 950.degree. C.; or at least about
980.degree. C. In some embodiments, the molten electrolyte
bath/cell operating temperature is: not greater than about
750.degree. C.; not greater than about 800.degree. C.; not greater
than about 850.degree. C.; not greater than about 900.degree. C.;
not greater than about 950.degree. C.; or not greater than about
980.degree. C.
[0189] As used herein, "metal product" means the product which is
produced by electrolysis. In one embodiment, the metal product
forms at the bottom of an electrolysis cell as a metal pad. Some
non-limiting examples of metal products include: aluminum, nickel,
magnesium, copper, zinc, and rare earth metals.
[0190] As used herein, "sidewall" means the wall of an electrolysis
cell. In some embodiments, the sidewall runs parametrically around
the cell bottom and extends upward from the cell bottom to defines
the body of the electrolysis cell and define the volume where the
electrolyte bath is held. In some embodiments, the sidewall
includes: an outer shell, a thermal insulation package, and an
inner wall. In some embodiments, the inner wall and cell bottom are
configured to contact and retain the molten electrolyte bath, the
feed material which is provided to the bath (i.e. to drive
electrolysis) and the metal product (e.g. metal pad). In some
embodiments, the sidewall (inner sidewall) includes a polarized
sidewall portion. In some embodiments, the sidewall (inner
sidewall) includes a non-reactive sidewall portion (e.g. stable
sidewall portion). In some embodiments, the sidewall (inner
sidewall) includes: a thermal conductor portion. In some
embodiments, the sidewall (inner sidewall) includes: a frozen ledge
device. In some embodiments, the sidewall (inner sidewall) is
configured to accept and retain a protecting deposit along a
portion thereof.
[0191] As used herein, "transverse" means an angle between two
surfaces. In some embodiments, the surfaces make an acute or an
obtuse angle. In some embodiments, transverse includes an angle at
or that is equal to the perpendicular angle or almost no angle,
i.e. surfaces appearing as continuous (e.g. 180.degree.). In some
embodiments, a portion of the sidewall (inner wall) is transverse,
or angled towards the cell bottom. In some embodiments, the entire
sidewall is transverse to the cell bottom.
[0192] In some embodiments, the entire wall is transverse. In some
embodiments, a portion of the wall (first sidewall portion, second
sidewall portion, shelf, trough, directing member) is transverse
(or, sloped, angled, curved, arcuate).
[0193] In some embodiments, the shelf is transverse. In some
embodiments, the second sidewall portion is transverse. Without
being bound by any particular theory or mechanism, it is believed
that by configuring the sidewall (first sidewall portion, second
sidewall portion, trough, or shelf) in a transverse manner, it is
possible to promote certain characteristics of the cell in
operation (e.g. metal drain, feed material direction into the
cell/towards the cell bottom). As a non-limiting example, by
providing a transverse sidewall, the sidewall is configured to
promote feed material capture into a protecting deposit in a trough
or shelf (e.g. angled towards /or is configured to promote metal
drain into the bottom of the cell. An angle to the shelf,
[0194] In some embodiments, the first sidewall portion is
transverse (angled/sloped) and the second sidewall portion is not
sloped. In some embodiments, the first sidewall portion is not
sloped and the second sidewall portion is sloped. In some
embodiments, both the first sidewall portion and the second
sidewall portion are transverse (angled/sloped).
[0195] In some embodiments, the base (or feed block) is transverse
(sloped or angled). In some embodiments, the upper portion of the
shelf/trough or second sidewall portion is sloped, angled, flat,
transverse, or curved.
[0196] As used herein, "wall angle", means the angle of the inner
sidewall relative to the cell bottom measurable in degrees. For
example, a wall angle of 0 degrees refers to a vertical angle (or
no angle). In some embodiments, the wall angle comprises: an angle
(theta) from 0 degrees to about 30 degrees. In some embodiments,
the wall angle comprises an angle (theta) from 0 degrees to 60
degrees. In some embodiments, the wall angle comprises an angle
(theta) from about 0 to about 85 degrees.
[0197] In some embodiments, the wall angle (theta) is: at least
about 5.degree.; at least about 10.degree.; at least about
15.degree.; at least about 20.degree.; at least about 25.degree.;
at least about 30.degree.; at least about 35.degree.; at least
about 40.degree.; at least about 45.degree.; at least about
50.degree.; at least about 55.degree.; or at least about
60.degree.. In some embodiments, the wall angle (theta) is: not
greater than about 5.degree.; not greater than about 10.degree.;
not greater than about 15.degree.; not greater than about
20.degree.; not greater than about 25.degree.; not greater than
about 30.degree.; not greater than about 35.degree.; not greater
than about 40.degree.; not greater than about 45.degree.; not
greater than about 50.degree.; not greater than about 55.degree.;
or not greater than about 60.degree..
[0198] As used herein, "outer shell" means an outer-most protecting
cover portion of the sidewall. In one embodiment, the outer shell
is the protecting cover of the inner wall of the electrolysis cell.
As non-limiting examples, the outer shell is constructed of a hard
material that encloses the cell (e.g. steel).
[0199] As used herein, "frozen" refers to something that is rigid
and immobilized as a result of thermal energy.
[0200] As used herein, "ledge" refers to projecting member.
[0201] As used herein, "frozen ledge" refers to something that is
rigid and immobilized in a projecting configuration. In some
embodiments, the frozen ledge includes a portion of the
electrolytic bath adjacent to the sidewall that freezes to form a
rigid ledge along a portion of the sidewall (e.g. in a generally
horizontal manner). In some embodiments, the frozen ledge is formed
and/or maintained by the sidewall materials (e.g. frozen ledge
device or thermal conductor material) which are configured to
extract/transfer heat from the bath adjacent to the sidewall. In
some embodiments, the frozen ledge is formed due to temperature
differences in the bath (e.g. lower temperature along the sidewall
as compared to the center of the cell).
[0202] As used herein, "first sidewall portion" means a portion of
the inner sidewall.
[0203] As used herein, "second sidewall portion" means another
portion of the inner sidewall. In some embodiments, the second
portion is a distance (e.g. longitudinally spaced) from the first
portion. As one non-limiting example, the second sidewall portion
is an upright member having a length and a width, wherein the
second portion is spaced apart from the first portion.
[0204] In some embodiments, the second portion cooperates with the
first portion to retain a material or object (e.g. protecting
deposit, portion of frozen ledge).
[0205] In some embodiments, the second portion is of a continuous
height, while in other embodiments, the second portion's height
varies. In one embodiment, the second portion is constructed of a
material that is resistant to the corrosive environment of the bath
and resistant to the metal product (e.g. metal pad), and thus, does
not break down or otherwise react in the bath. As some non-limiting
examples, the wall is constructed of: Al.sub.2O.sub.3, TiB.sub.2,
SiC, Si.sub.3N.sub.4, BN, a bath component that is at or near
saturation in the bath chemistry (e.g. alumina), and combinations
thereof.
[0206] In some embodiments, the second portion is electrically
conductive and assists in transferring current from the bath to the
cathode(s). In some embodiments, the second portion is cast, hot
pressed, or sintered into the desired dimension, theoretical
density, porosity, and the like. In some embodiments, the second
portion is secured to one or more cell components in order to keep
the second portion in place.
[0207] As used herein, "directing member" means a member which is
configured to direct an object or material in a particular manner.
In some embodiments, the directing member is adapted and configured
to direct a feed material into a trough (e.g. to be retained in the
trough as protecting deposit.) In some embodiments, the directing
member is suspended in the cell between the first sidewall portion
and the second sidewall, and above the trough in order to direct
the flow of the feed material into the trough. In some embodiments,
the directing member comprises a polarized sidewall portion (e.g.
cathodically polarized sidewall portion or anodically polarized
sidewall portion). In some embodiments, the directing member is
constructed of a material (at least one bath component) which is
present in the bath chemistry at or near saturation, such that in
the bath the directing member is maintained. In some embodiments,
the directing member is configured to attach to a frame (e.g. of
bath resistant material), where the frame is configured to adjust
the directing member in the cell (i.e. move the directing member
laterally (e.g. up or down relative to the cell height) and/or move
the directing member longitudinally (e.g. left or right relative to
the trough/cell bottom).
[0208] In some embodiments, the dimension of and/or the location of
the directing member is selected to promote a certain configuration
of the protecting deposit and/or a predetermined feed material flow
pattern into the trough. In some embodiments, the directing member
is attached to the anode assembly. In some embodiments, the
directing member is attached to the sidewall of the cell. In some
embodiments, the directing member is attached to the feed device
(e.g. frame which holds the feed device into position. As
non-limiting examples, the directing member comprises a plate, a
rod, a block, an elongated member form, and combinations thereof.
Some non-limiting examples of directing member materials include:
anode materials; SiC; SiN; and/or components which are present in
the bath at or near saturation such that the directing member is
maintained in the bath.
[0209] As used herein, "longitudinally spaced" means the placement
of one object from another object in relation to a length. In some
embodiments, laterally spaced (i.e. the second sidewall portion
from the first sidewall portion--or the trough) means: at least
1'', at least 11/2'', at least 2'', at least 2 1/2'', at least 3'',
at least 3 1/2'', at least 4'', at least 4 1/2'', at least 5'', at
least 5 1/2'', at least 6'', at least 6 1/2'', at least 7'', at
least 7 1/2'', at least 8'', at least 8 1/2'', at least 9'', at
least 9 1/2'', at least 10'', at least 10 1/2'', at least 11'', at
least 11 1/2'', or at least 12''.
[0210] In some embodiments, laterally spaced (i.e. the second
sidewall portion from the first sidewall portion--or the trough)
means: not greater than 1'', not greater than 11/2'', not greater
than 2'', not greater than 2 1/2'', not greater than 3'', not
greater than 3 1/2'', not greater than 4'', not greater than 4
1/2'', not greater than 5'', not greater than 5 1/2'', not greater
than 6'', not greater than 6 1/2'', not greater than 7'', not
greater than 7 1/2'', not greater than 8'', not greater than 8
1/2'', not greater than 9'', not greater than 9 1/2'', not greater
than 10'', not greater than 10 1/2'', not greater than 11'', not
greater than 11 1/2'', or not greater than 12''. As used herein,
"laterally spaced" means the placement of one object from another
object in relation to a width.
[0211] In some embodiments, the first sidewall portion is set a
given distance from the second sidewall portion to define a trough
(i.e. having trough width). In some embodiments, the trough width
is from 10 mm to not greater than 500 mm. In some embodiments, the
trough width is from 50 mm to not greater than 200 mm. In some
embodiments, the trough width is from 75 mm to not greater than 150
mm.
[0212] In some embodiments, the trough (e.g. trough width) is: at
least 10 mm; at least 20 mm; at least 30 mm; at least 40 mm; at
least 50 mm; at least 60 mm; at least 70 mm; at least 80 mm; at
least 90 mm; at least 100 mm; at least 110 mm; at least 120 mm; at
least 130 mm; at least 140 mm; at least 150 mm; at least 160 mm; at
least 170 mm; at least 180 mm; at least 190 mm; at least 200 mm; at
least 210 mm; at least 220 mm; at least 230 mm; at least 240 mm; at
least 250 mm; at least 260 mm; at least 270 mm; at least 280 mm; at
least 290 mm; at least 300 mm; at least 310 mm; at least 320 mm; at
least 330 mm; at least 340 mm; at least 350 mm; at least 360 mm; at
least 370 mm; at least 380 mm; at least 390 mm; at least 400 mm; at
least 410 mm; at least 420 mm; at least 430 mm; at least 440 mm; at
least 450 mm; at least 460 mm; at least 470 mm; at least 480 mm; at
least 490 mm; or at least 500 mm.
[0213] In some embodiments, the trough (e.g. trough width) is: not
greater than 10 mm; not greater than 20 mm; not greater than 30 mm;
not greater than 40 mm; not greater than 50 mm; not greater than 60
mm; not greater than 70 mm; not greater than 80 mm; not greater
than 90 mm; not greater than 100 mm; not greater than 110 mm; not
greater than 120 mm; not greater than 130 mm; not greater than 140
mm; not greater than 150 mm; not greater than 160 mm; not greater
than 170 mm; not greater than 180 mm; not greater than 190 mm; not
greater than 200 mm; not greater than 210 mm; not greater than 220
mm; not greater than 230 mm; not greater than 240 mm; not greater
than 250 mm; not greater than 260 mm; not greater than 270 mm; 280
mm; not greater than 290 mm; at least 300 mm; at least 310 mm; at
least 320 mm; at least 330 not greater than mm; not greater than
340 mm; not greater than 350 mm; not greater than 360 mm; not
greater than 370 mm; not greater than 380 mm; not greater than 390
mm; not greater than 400 mm; not greater than 410 mm; not greater
than 420 mm; not greater than 430 mm; not greater than 440 mm; not
greater than 450 mm; not greater than 460 mm; not greater than 470
mm; not greater than 480 mm; not greater than 490 mm; or not
greater than 500 mm.
[0214] As used herein, "at least" means greater than or equal
to.
[0215] As used herein, "not greater than" means less than or equal
to.
[0216] As used herein, "trough" means a receptacle for retaining
something. In one embodiment, the trough is defined by the first
sidewall portion, the second sidewall portion, and the base (or
bottom of the cell). In some embodiments, the trough retains the
protecting deposit. In other embodiments, the trough retains a
frozen ledge or frozen portion (e.g. defined via a thermal
conductor or the frozen ledge device). In some embodiments the
trough retains a feed material in the form of a protecting deposit,
such that the trough is configured to prevent the protecting
deposit from moving within the cell (i.e. into the metal pad and/or
electrode portion of the cell).
[0217] In some embodiments, the trough further comprises a height
(e.g. relative to the sidewall). As non-limiting embodiments, the
trough height (as measured from the bottom of the cell to the
bath/vapor interface comprises: at least 1/4'', at least 1/2'', at
least 3/4'', at least 1'', at least 1 1/4'', at least 1 1/2'', at
least 1 3/4'', at least 2'', at least 2 1/4'', at least 2 1/2'', at
least 2 3/4'', at least 3'', 3 1/2'', at least 3 3/4'', at least 3
3/4'', at least 4'', 4 1/4'', at least 4 1/2'', at least 4 3/4'',
at least 5'', 5 1/4'', at least 5 1/2'', at least 5 3/4'', or at
least 6''. In some embodiments, the trough height comprises: at
least 6'' at least 12'' at least 18'', at least 24'', or at least
30''.
[0218] As non-limiting embodiments, the trough height (as measured
from the bottom of the cell to the bath/vapor interface comprises:
not greater than 1/4'', not greater than 1/2'', not greater than
3/4'', not greater than 1'', not greater than 11/4'', not greater
than 11/2'', not greater than 13/4'', not greater than 2'', not
greater than 21/4'', not greater than 2 1/2'', not greater than 2
3/4'', not greater than 3'', 3 1/4'', not greater than 3 1/2'', not
greater than 3 3/4'', not greater than 4'', 4 1/4'', not greater
than 4 1/2'', not greater than 4 3/4'', not greater than 5'', 5
1/4'', not greater than 5 1/2'', not greater than 5 3/4'',or not
greater than 6''. In some embodiments, the trough height comprises:
not greater than 6'' not greater than 12'' not greater than 18'',
not greater than 24'', or not greater than 30''.
[0219] In some embodiments, the second sidewall portion extends in
an upward position (i.e. relative to the cell bottom), such that
the second sidewall portion overlaps for a given distance with the
first sidewall portion (i.e. to define a portion where two sidewall
portions overlap, a common "trough overlap"). In some embodiments,
the trough overlap is quantifiable via the overlap relative to the
overall cell wall height (e.g. expressed as a percentage). In some
embodiments, the trough overlap is from 0% to not greater than 90%
of the total cell wall height. In some embodiments, the trough
overlap is from 20% to not greater than 80% of the total cell wall
height. In some embodiments, the trough overlap is from 40% to not
greater than 60% of the total cell wall height.
[0220] In some embodiments, the trough overlap is: 0% (i.e. no
overlap); at least 5% of the total wall height; at least 10% of the
total wall height; at least 15% of the total wall height; at least
20% of the total wall height; at least 25% of the total wall
height; at least 30% of the total wall height; at least 35% of the
total wall height; at least 40% of the total wall height; at least
45% of the total wall height; at least 50% of the total wall
height; at least 55% of the total wall height; at least 60% of the
total wall height; at least 65% of the total wall height; at least
70% of the total wall height; at least 75% of the total wall
height; at least 80% of the total wall height; at least 85% of the
total wall height; or at least 90% of the total wall height.
[0221] In some embodiments, the trough overlap is: 0% (i.e. no
overlap); not greater than 5% of the total wall height; not greater
than 10% of the total wall height; not greater than 15% of the
total wall height; not greater than 20% of the total wall height;
not greater than 25% of the total wall height; not greater than 30%
of the total wall height; not greater than 35% of the total wall
height; not greater than 40% of the total wall height; not greater
than 45% of the total wall height; not greater than 50% of the
total wall height; not greater than 55% of the total wall height;
not greater than 60% of the total wall height; not greater than 65%
of the total wall height; not greater than 70% of the total wall
height; not greater than 75% of the total wall height; not greater
than 80% of the total wall height; not greater than 85% of the
total wall height; or not greater than 90% of the total wall
height.
[0222] In some embodiments, the trough comprises a polarized
sidewall portion (e.g. cathodically polarized sidewall portion). In
some embodiments, the trough is constructed of a material (at least
one bath component) which is present in the bath chemistry at or
near saturation, such that in the bath it is maintained.
[0223] As used herein, "protecting deposit" refers to an
accumulation of a material that protects another object or
material. As a non-limiting example, a "protecting deposit" refers
to the feed material that is retained in the trough. In some
embodiments, the protecting deposit is: a solid; a particulate
form; a sludge; a slurry; and/or combinations thereof. In some
embodiments, the protecting deposit is dissolved into the bath
(e.g. by the corrosive nature of the bath) and/or is consumed
through the electrolytic process. In some embodiments, the
protecting deposit is retained in the trough, between the first
sidewall portion and the second sidewall portion. In some
embodiments, the protecting deposit is configured to push the metal
pad (molten metal) away from the sidewall, thus protecting the
sidewall from the bath-metal interface. In some embodiments, the
protecting deposit is dissolved via the bath to provide a
saturation at or near the cell wall which maintains the
stable/non-reactive sidewall material (i.e. composed of a bath
component at or near saturation). In some embodiments the
protecting deposit comprises an angle of deposit (e.g. the
protecting deposit forms a shape as it collects in the trough),
sufficient to protect the sidewall and provide feed material to the
bath for dissolution.
[0224] As used herein, "feed material" means a material that is a
supply that assists the drive of further processes. As one
non-limiting example, the feed material is a metal oxide which
drives electrolytic production of rare earth and/or non-ferrous
metals (e.g. metal products) in an electrolysis cell. In some
embodiments, the feed material once dissolved or otherwise
consumed, supplies the electrolytic bath with additional starting
material from which the metal oxide is produced via reduction in
the cell, forming a metal product. In some embodiments, the feed
material has two non-limiting functions: (1) feeding the reactive
conditions of the cell to produce metal product; and (2) forming a
feed deposit in the channel between the wall at the inner sidewall
to protect the inner sidewall from the corrosive bath environment.
In some embodiments, the feed material comprises alumina in an
aluminum electrolysis cell. Some non-limiting examples of feed
material in aluminum smelting include: smelter grade alumina (SGA),
alumina, tabular aluminum, and combinations thereof. In the
smelting of other metals (non-aluminum), feed materials to drive
those reactions are readily recognized in accordance with the
present description. In some embodiments, the feed material is of
sufficient size and density to travel from the bath-air interface,
through the bath and into the trough to form a protecting
deposit.
[0225] As used herein, "average particle size" refers to the mean
size of a plurality of individual particles. In some embodiments,
the feed material in particulate (solid) form having an average
particle size. In one embodiment, the average particle size of the
feed material is large enough so that it settles into the bottom of
the cell (e.g. and is not suspended in the bath or otherwise
"float" in the bath). In one embodiment, the average particle size
is small enough so that there is adequate surface area for surface
reactions/dissolution to occur (e.g. consumption rate).
[0226] As used herein, "feed rate" means a certain quantity (or
amount) of feed in relation to a unit of time. As one non-limiting
example, feed rate is the rate of adding the feed material to the
cell. In some embodiments, the size and/or position of the
protecting deposit is a function of the feed rate. In some
embodiment, the feed rate is fixed. In another embodiment, the feed
rate is adjustable. In some embodiments, the feed is continuous. In
some embodiments, the feed is discontinuous.
[0227] As used herein, "consumption rate" means a certain quantity
(or amount) of use of a material in relation to a unit of time. In
one embodiment, consumption rate is the rate that the feed material
is consumed by the electrolysis cell (e.g. by the bath, and/or
consumed to form metal product).
[0228] In some embodiments, the feed rate is higher than the
consumption rate. In some embodiment, the feed rate is configured
to provide a protecting deposit above the bath-air interface.
[0229] As used herein, "feeder" (sometimes called a feed device)
refers to a device that inputs material (e.g. feed) into something.
In one embodiment, the feed device is a device that feeds the feed
material into the electrolysis cell. In some embodiments, the feed
device is automatic, manual, or a combination thereof. As
non-limiting examples, the feed device is a curtain feeder or a
choke feeder. As used herein, "curtain feeder" refers to a feed
device that moves along the sidewall (e.g. with a track) to
distribute feed material. In one embodiment, the curtain feeder is
movably attached so that it moves along at least one sidewall of
the electrolysis cell. As used herein, "choke feeder" refers to a
feed device that is stationary on a sidewall to distribute feed
material into the cell. In some embodiments, the feed device is
attached to the sidewall by an attachment apparatus. Non-limiting
examples include braces, and the like.
[0230] In some embodiments, the feed device is automatic. As used
herein, "automatic" refers to the capability to operate
independently (e.g. as with machine or computer control). In some
embodiments, the feed device is manual. As used herein, "manual"
means operated by human effort.
[0231] As used herein, "feed block" refers to feed material in
solid form (e.g. cast, sintered, hot pressed, or combinations
thereof). In some embodiments, the base of the trough comprises a
feed block. As one non-limiting example, the feed block is made of
alumina. In some embodiments, the feed block is a solid block (e.g.
of any shape or dimension) of the feed material and/or another bath
component.
[0232] As used herein, "polarized" means a material that has a
positive or negative electric potential imparted in it.
[0233] As used herein, "polarized sidewall" refers to a wall
portion that is polarized to have a charge. In one embodiment,
polarized sidewall is a portion of the inner wall of the cell that
has a positive polarization (e.g. anodic or anodically polarized),
negative polarization (cathodic or cathodically polarized), or
combination thereof. In some embodiments, the polarized sidewall
assists in the electrolysis process. In some embodiments, the
polarized sidewall portions include a first material and a second
material, where the first material is different from the second
material.
[0234] In some embodiments, the polarized sidewall comprises a
percentage of the total sidewall/percentage of the total surface
area of the sidewall (e.g. portion of the sidewall attached to the
thermal insulation package). In some embodiments, the polarized
sidewall is: at least about 1%; at least about 5%; at least about
10%; at least about 15%; at least about 20%; at least about 25%; at
least about 30%; at least about 35%; at least about 40%; at least
about 45%; at least about 50%; at least about 55%; at least about
60%; at least about 65%; at least about 70%; at least about 75%; at
least about 80%; at least about 85%; at least about 90%; at least
about 95%; or 100% of the surface area of the sidewall (i.e.
sidewall configured to attach to the thermal insulation package, or
second sidewall portion).
[0235] In some embodiments, the polarized sidewall is: not greater
than about 1%; not greater than about 5%; not greater than about
10%; not greater than about 15%; not greater than about 20%; not
greater than about 25%; not greater than about 30%; not greater
than about 35%; not greater than about 40%; not greater than about
45%; not greater than about 50%; not greater than about 55%; not
greater than about 60%; not greater than about 65%; not greater
than about 70%; not greater than about 75%; not greater than about
80%; not greater than about 85%; not greater than about 90%; not
greater than about 95%; or 100% of the surface area of the sidewall
(i.e. sidewall configured to attach to the thermal insulation
package, or second sidewall portion).
[0236] As used herein, "anodic sidewall" (also called an anodically
polarized sidewall), means a sidewall material that has a positive
charge on it (or through it) so that the sidewall acts in an anodic
fashion in an electrolysis cell. In some embodiments, the anodic
sidewall is located above the cell bottom. In some embodiments, the
anodic sidewall is located at a height which is above the metal
pad. In some embodiments, the anodic sidewall is located at a
height above the bath-metal interface. In some embodiments, the
electrically connected portion of the anodic sidewall is located in
an elevated position along the inner sidewall, remote from the
bottom.
[0237] As used herein, "anodic sidewall electrical connection"
means the electrical connection which provides the positive charge
to the surface of the anodic sidewall. In some embodiments, the
electrical connection supplies current to the anodic sidewall. In
some embodiments, the electrical connection includes a conductor
pin. In some embodiments, the electrical connection includes a
conductor bar. As one non-limiting example, the electrical
connection is the collector bar and the conductor pin, which are
embedded inside of the anodic sidewall.
[0238] As used herein, "cathodic sidewall", means a sidewall that
has a negative charge on it (or through it) so that it acts in a
cathodic fashion in an electrolysis cell. In some embodiments, the
cathodic sidewall is in communication with the cell bottom. In some
embodiments, the cathodic sidewall is in communication with the
metal product/metal pad. In some embodiments, the cathodic sidewall
is at a height which is below the bath-air interface. In some
embodiments, the cathodic sidewall is located in the electrolyte
bath.
[0239] As used herein, "cathodic sidewall electrical connection"
means the electrical connection which provides the negative charge
to the surface of the anodic sidewall. In some embodiments, the
electrical connection removes current from the cathodic sidewall.
In some embodiments, the electrical connection includes a conductor
bar. As one non-limiting example, the electrical connection is the
collector bar, which is embedded inside of the cathodic sidewall.
In some embodiments, the electrical connection is provided by
contact of (e.g. mechanical connection/attachment) of the cathodic
sidewall to the cathode. In some embodiments, the electrical
connection is provided by the contact of the cathodic sidewall to
the metal pad, which is cathodic due to its contact with the
cathode.
[0240] As used herein, "non-polarized" means an object or material
which is not configured to carry current (i.e. is not anodically or
cathodically polarized). In some embodiments, the non-polarized
sidewall is configured to provide electrical insulation to at least
one (or two) polarized sidewall portions. Some non-limiting
examples of a non-polarized material include: a thermal conductor
material, a non-reactive material, and a frozen ledge device.
[0241] In some embodiments, the non-polarized sidewall comprises a
percentage of the total sidewall/percentage of the total surface
area of the sidewall (e.g. portion of the sidewall attached to the
thermal insulation package). In some embodiments, the non-polarized
sidewall is: at least about 1%; at least about 5%; at least about
10%; at least about 15%; at least about 20%; at least about 25%; at
least about 30%; at least about 35%; at least about 40%; at least
about 45%; at least about 50%; at least about 55%; at least about
60%; at least about 65%; at least about 70%; at least about 75%; at
least about 80%; at least about 85%; at least about 90%; at least
about 95%; or 100% of the surface area of the sidewall (i.e.
sidewall configured to attach to the thermal insulation package, or
second sidewall portion).
[0242] In some embodiments, the non-polarized sidewall is: not
greater than about 1%; not greater than about 5%; not greater than
about 10%; not greater than about 15%; not greater than about 20%;
not greater than about 25%; not greater than about 30%; not greater
than about 35%; not greater than about 40%; not greater than about
45%; not greater than about 50%; not greater than about 55%; not
greater than about 60%; not greater than about 65%; not greater
than about 70%; not greater than about 75%; not greater than about
80%; not greater than about 85%; not greater than about 90%; not
greater than about 95%; or 100% of the surface area of the sidewall
(i.e. sidewall configured to attach to the thermal insulation
package, or second sidewall portion).
[0243] As used herein, "thermal conductor" refers to a substance
(or medium) that conducts thermal energy (e.g. heat). In some
embodiments, the thermal conductor material is a portion of the
sidewall. In some embodiments, the thermal conductor material is
configured to transfer heat from the molten electrolyte bath
through its body, thus removing heat from the cell. In some
embodiments, due to the heat transfer across the face of the
thermal conductor, a frozen ledge portion is generated at the
bath-thermal conductor interface. In some embodiments, the frozen
ledge defined by the thermal conductor acts as an electrical
insulator along a portion of the sidewall of the cell. Some
non-limiting examples of thermal conductor materials include: SiC,
graphite, metal, or metal alloys, Si3N4, BN, stainless steel,
metal, and metal alloy, and combinations thereof.
[0244] As used herein, "insulator", means a material or an object
that does not easily allow electricity, to pass through it. As a
non-limiting example, an insulator refers to a material that is
resistant to the transfer of electricity. In some embodiments of
the instant disclosure, insulators are provided along portions of
the sidewall to electrically insulate one portion from another
(e.g. an anodically polarized sidewall portion from a cathodically
polarized sidewall portion; an anodically polarized sidewall
portion from a cell bottom (or metal pad); or combinations thereof.
Some non-limiting examples of insulators include: non-reactive
(e.g. stable) sidewall materials, thermal conductor sidewalls,
polarized sidewalls, and/or a frozen ledge device.
[0245] As used herein, "stable" means a material that is generally
non-reactive and/or retains its properties within an environment.
In some embodiments, the sidewall material is stable (or
non-reactive, as set out below) in the electrolytic cell
environment, given the cell conditions and operating
parameters.
[0246] Though not wishing to be bound by a particular mechanism or
theory, if the cell environment is maintained /kept constant (e.g.
including maintaining the feed material in the cell at saturation
for the particular cell system), then the sidewall material is
truly stable in that it will not react or dissolve into the bath.
However, an operating electrolytic cell is difficult, if not
impossible to maintain at constant cell operating parameters, as
the operating cell is characterized by constant change (at least as
far as reducing feed material into metal product via
electrochemistry). Without wanting to be bound by a particular
mechanism or theory, it is believed that the temperature flux is
changing (as the current flux and any other process variation will
change the temperature of the cell/bath); the feed flux is ever
changing, even with optimized distribution, as different feed
locations and/or feed rates will impact solubility (i.e. of the
stable material(s)) throughout the cell; and analytical tools and
methods to quantify and control cell processes inherently have some
attributable error to the calibration of solubility limits (e.g.
LECO methods used to determine the alumina content in the cell has
an error range of +/-5%).
[0247] In some embodiments, stable materials and/or non-reactive
sidewall materials do not react or degrade (e.g. when the bath is
at saturation for that particular material). In other embodiments,
stable materials and/or non-reactive materials undergo a small
amount of dissolution (i.e. within a predetermined threshold), such
that the sidewall material does not fail cell during electrolysis
and cell operation (i.e. maintains the molten electrolyte). In this
embodiment, as the content of the feed material in the bath (i.e.
quantifiable as % of saturation) inevitably varies as a function of
cell operation, so too will the dissolution either cease or
initiate, and/or the dissolution rate of the stable sidewall
material decrease or increase.
[0248] In some embodiments, a stable sidewall is maintained via
modulating dissolution. In some embodiments, dissolution is
modulated to within acceptable limits (e.g. small amounts of and/or
no dissolution) by controlled the feed rate and/or feed locations
(e.g. to impact the % saturation of feed material in the bath).
[0249] In some embodiments, the cations of such component materials
(Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, Y, La, and Ce) are
electrochemically less noble than the metal that is produced, so
they are not consumed during electrolysis. Put another way, since
the electrochemical potential of these materials is more negative
than aluminum, in an aluminum electrolytic cell, these materials
are less likely to be reduced.
[0250] As used here, "non-reactive sidewall" refers to a sidewall
which is constructed or composed of (e.g. coated with) a material
which is stable (e.g. non-reactive, inert, dimensionally stable,
and/or maintained) in the molten electrolyte bath at cell operating
temperatures (e.g. above 750.degree. C. to not greater than
980.degree. C.). In some embodiments, the non-reactive sidewall
material is maintained in the bath due to the bath chemistry. In
some embodiments, the non-reactive sidewall material is stable in
the electrolyte bath since the bath comprises the non-reactive
sidewall material as a bath component in a concentration at or near
its saturation limit in the bath. In some embodiments, the
non-reactive sidewall material comprises at least one component
that is present in the bath chemistry. In some embodiments, the
bath chemistry is maintained by feeding a feed material into the
bath, thus keeping the bath chemistry at or near saturation for the
non-reactive sidewall material, thus maintaining the sidewall
material in the bath.
[0251] Some non-limiting examples of non-reactive sidewall
materials include: Al; Li; Na; K; Rb; Cs; Be; Mg; Ca; Sr; Ba; Sc;
Y; La; or Ce-containing materials, and combinations thereof. In
some embodiments, the non-reactive material is an oxide of the
aforementioned examples. In some embodiments, the non-reactive
material is a halide salt and/or fluoride of the aforementioned
examples. In some embodiments, the non-reactive material is an
oxofluoride of the aforementioned examples. In some embodiments,
the non-reactive material is pure metal form of the aforementioned
examples. In some embodiments, the non-reactive sidewall material
is selected to be a material (e.g. Ca, Mg) that has a higher
electrochemical potential than (e.g. cations of these materials are
electrochemically more noble than) the metal product being produced
(e.g. Al), the reaction of the non-reactive sidewall material is
less desirable (electrochemically) than the reduction reaction of
Alumina to Aluminum. In some embodiments, the non-reactive sidewall
is made from castable materials. In some embodiments, the
non-reactive sidewall is made of sintered materials.
[0252] In some embodiments the sidewall has a thickness of from 3
mm to not greater than 500 mm.
[0253] In some embodiments, the thickness of the sidewall is: at
least 3 mm; at least 5 mm; at least 10 mm; at least 15 mm; at least
20 mm; at least 25 mm; at least 30 mm; at least 35 mm; at least 40
mm; at least 45 mm; at least 50 mm; at least 55 mm; at least 60 mm;
at least 65 mm; at least 70 mm; at least 75 mm; at least 80 mm; at
least 85 mm; at least 90 mm; at least 95 mm; or at least 100
mm.
[0254] In some embodiments, the thickness of the sidewall is: at
least 100 mm; at least 125 mm; at least 150 mm; at least 175 mm; at
least 200 mm; at least 225 mm; at least 250 mm; at least 275 mm; at
least 300 mm; at least 325 mm; at least 350 mm; at least 375 mm; at
least 400 mm; at least 425 mm; at least 450 mm; at least 475 mm; or
at least 500 mm.
[0255] In some embodiments, the thickness of the sidewall is: not
greater than 3 mm; not greater than 5 mm; not greater than 10 mm;
not greater than 15 mm; not greater than 20 mm; not greater than 25
mm; not greater than 30 mm; not greater than 35 mm; not greater
than 40 mm; not greater than 45 mm; not greater than 50 mm; not
greater than 55 mm; not greater than 60 mm; not greater than 65 mm;
not greater than 70 mm; not greater than 75 mm; not greater than 80
mm; not greater than 85 mm; not greater than 90 mm; not greater
than 95 mm; or not greater than 100 mm.
[0256] In some embodiments, the thickness of the sidewall is: not
greater than 100 mm; not greater than 125 mm; not greater than 150
mm; not greater than 175 mm; not greater than 200 mm; not greater
than 225 mm; not greater than 250 mm; not greater than 275 mm; not
greater than 300 mm; not greater than 325 mm; not greater than 350
mm; not greater than 375 mm; not greater than 400 mm; not greater
than 425 mm; not greater than 450 mm; not greater than 475 mm; or
not greater than 500 mm.
[0257] In some embodiments the polarized sidewall has a thickness
of from 3 mm to not greater than 500 mm. In some embodiments, the
polarized sidewall has a thickness of from 10 mm to 200 mm. In some
embodiments, the polarized sidewall has a thickness of from 40 mm
to 100 mm.
[0258] In some embodiments the stable sidewall has a thickness of
from 3 mm to not greater than 500 mm. In some embodiments, the
stable sidewall has a thickness of from 50 mm to not greater than
400 mm. In some embodiments, the stable sidewall has a thickness of
from 100 mm to not greater than 300 mm. In some embodiments, the
stable sidewall has a thickness of from 150 mm to not greater than
250 mm.
EXAMPLE
Bench Scale Study: Side Feeding
[0259] Bench scale tests were completed to evaluate the
corrosion-erosion of an aluminum electrolysis cell. The
corrosion-erosion tests showed that alumina, and chromia-alumina
materials were preferentially attacked at the bath-metal interface.
Also, it was determined that the corrosion-erosion rate at the
bath-metal interface is accelerated dramatically when alumina
saturation concentration is low (e.g. below about 95 wt. %). With a
physical barrier of feeding materials, i.e. to feed increase the
alumina saturation concentration, the barrier (e.g. of alumina
particles) operated to keep alumina saturated at bath-metal
interface to protect the sidewall from being dissolved by the bath.
Thus, the sidewall at the bath-metal interface is protected from
corrosive-erosive attack and the aluminum saturation concentration
was kept at about 98 wt. %. After performing electrolysis for a
period of time, the sidewall was inspected and remained intact.
EXAMPLE
Pilot Scale Test: Automated Side feeding with Rotary Feeder
[0260] A single hall cell was operated continuously for about 700
hr with a trough along the sidewall around the perimeter of the
cell (e.g. via a rotary feeder). The feeder included a hopper, and
rotated along the sidewall to feed the entire sidewall (along one
sidewall). A feed material of tabular alumina was fed into the cell
at a location to be retained in the trough by an automatic feeder
device. After electrolysis was complete, the sidewall was inspected
and found intact (i.e. the sidewall was protected by the side
feeding). The rotary feeder along the sidewall is depicted in FIG.
31.
EXAMPLE
Full Pot Test Side Feeding (Manual)
[0261] A commercial scale test on sidewall feeding was operated
continuously for a period of time (e.g. at least one month) with a
trough along the sidewall via manual feeding. A feed material of
tabular alumina was fed into the cell manually at a location
adjacent to the sidewall such that the alumina was retained in a
trough in the cell, located adjacent to the sidewall. Measurements
of the sidewall profile showed minimum corrosion-erosion of the
sidewall above the trough, and trough profile measurements
indicated that the trough maintained its integrity throughout the
operation of the cell. Thus, the manually fed alumina protected the
metal-bath interface of the sidewall of the cell from
corrosion-erosion. An autopsy of the cell was performed to
conclusively illustrate the foregoing.
EXAMPLE
Polarized Sidewalls with Side Feeding
[0262] Bench tests and pilot tests were performed (e.g. 100 A cell
up to 25 kA cell), with some tests running for as long as nine
months. The Sidewall included an anodic portion and a cathodic
portion, with a feeder providing a protecting deposit to act as an
insulator there between, as depicted in FIGS. 22 and 33. After the
cell was run, the sidewalls were evaluated and confirmed to be
intact.
EXAMPLE
Frozen Ledge Device
[0263] A pilot scale test was performed with a frozen ledge device
(e.g. frozen finger) due to the scale-down, in a crucible reactor.
The frozen ledge device operated to form a frozen portion of bath
along the surface of the frozen ledge device. FIGS. 29-30 depict
the frozen ledge device and the experimental set up within the
crucible reactor.
EXAMPLE
Average % Saturation of Alumina vs. Max Wear Rate (Dissolution
Rate)
[0264] Five Electrolytic Cells (i.e. Cell 1-5) were operated for a
period of time to produce aluminum on a bench scale. The Cells were
each the same size and had the same sidewall material (e.g.
alumina) with no seams in the sidewalls, where each Cell had the
same molten electrolyte material (bath). Each Cell was operated at
a different average saturation percentage of alumina in the bath,
where the Cells ranged from an average of 85.5% saturation (Cell 1)
to 98.92% saturation (Cell 5). Measurements were obtained on each
cell (e.g. at a position along the sidewall surface) to determine
the dissolution rate of the alumina sidewall. The maximum wear rate
(in mm/year) is provided in the table below. The data supports the
trend that as the average saturation increases, the max wear rate
decreases. The table provides that where the average saturation %
was within 2% of saturation (i.e. Cell 5), the maximum wear rate
(dissolution rate) was less than half of that than for Cell 1 (i.e.
31.97 mm/year vs. 75.77 mm/year), which operated at 85.5% of
saturation.
Average Saturation % and Max Wear Rate (Dissolution Rate) in
mm/Year for Cells 1-5
TABLE-US-00001 Max Wear Rate Cell Avg Sat'n % (mm/yr) Cell 1 85.5
75.77 Cell 2 91.99 73.58 Cell 3 93.65 57.81 Cell 4 94.42 45.11 Cell
5 98.92 31.97
EXAMPLE
Average % Saturation of Alumina vs. Max Wear Rate (Dissolution
Rate)
[0265] Three Electrolytic Cells (i.e. Cell 5-7) were operated for a
period of time to produce aluminum on a bench scale. Cells 5-7 were
operated to produce aluminum from alumina (feed material) and each
cell had alumina sidewalls and the same bath material (molten
electrolyte). Cells 5 and 6 were the same size (and also, Cells 1-6
were the same size), while Cell 7 was a larger pilot cell than
cells 1-6). Cell 7 had at least one seam, in addition to the
alumina sidewall material. For Cells 5-7, alumina saturation was
determined via analytical measurements every 4 hours (e.g. LECO
measurements). For Cell 5, alumina feed (saturation control) was
completed manually (e.g. via visual observation of the bath), while
alumina feed was automated for Cells 6 & 7 (e.g. with at least
the LECO measurement being incorporated into the automated system).
The three cells were each operated for varying periods of time
prior to shut down. During operation, alumina was added to Cell 5
based upon visual inspection (e.g. clear denoting an indication for
an "overfeed" event and cloudy denoting an indication for an
"underfeed" event). Cells 6 and 7 were fed based upon the automated
control system parameters, including the LECO measurements.
[0266] For Cells 5-7, each Cell was operated at a different average
saturation percentage of alumina in the bath, where the Cells
ranged from an average of 101.7% saturation (Cell 5) to 99.8%
saturation (Cell 6). Measurements were obtained on each cell (e.g.
at a position along the sidewall surface) to determine the
dissolution rate of the alumina sidewall as cell operation
progressed. For each cell, the average saturation % (alumina) is
provided, along with the maximum wear rate (dissolution rate) in
mm/year in the table below. Average saturation % values were
obtained via LECO measurements, which had a potential error of
+/-5%. In this instance, each Cell was operated with an average
saturation % that was close to or slightly above the saturation
limit of alumina (as computer for) the cell system with operating
parameters. In each Cell, muck was observed at one time or another,
where muck (alumina which settles from the bath) will accumulate
towards the cell bottom in the case where the cell is operated for
long periods of time with alumina contents above the saturation
limit (i.e. for the cell system and its operating parameters). Wear
rates were evaluated for Cell 7 at the seam (in addition to the
face/surface of the sidewall) and it is noted that, as expected,
the measured average wear rate at the seam was larger than that of
the face for Cell 7. It is noted that Cell 5 from the previous
Example is the same as Cell 5 from this Example, but the average
saturation was increased (i.e. from 98.92% to 101.7%).
Average Saturation % and Max Wear Rate (Dissolution Rate) in
mm/Year for Cells 5-7
TABLE-US-00002 Max Wear Rate Cell Avg Sat'n % (mm/yr) Cell 5 101.7
45.72 Cell 6 99.8 109.22 Cell 7 100.1 119.38
EXAMPLE
Average % Saturation of Alumina vs. Max Wear Rate (Dissolution
Rate)
[0267] Cell 8 was the same size as Cell 7 from the previous example
(e.g. larger size bench scale cell, with at least one seam and
alumina sidewall material). Cell 8 was operated at a number of days
at an average saturation of 98.5%, during which time a number of
wear measurements were taken along a given portion of one seam in
the cell. For Cell 8 operating at 98.5% of alumina saturation with
alumina walls, the wear rate at the seam was calculated. Following
operation for a number of days at an average saturation of 98.5%,
Cell 8 was operated for a number of days at an average saturation
of 98%, during which time a number of wear measurements were taken.
Again, wear rates at the seam were calculated for the same cell,
operating at 98% of alumina saturation. The average saturation
percents and maximum wear rates at the seam are provided in the
table, below. It is noted, that Cell 8 was operated for over a
month longer at an average saturation of 98.5% as compared its
operation at an average saturation of 98%. From the Table below, it
is shown that by operating the Cell at an average saturation of
just 0.5% higher, the wear rate at the seam was less than half the
rate of the lower average saturation's wear rate (dissolution rate)
(i.e. 109.73 mm/yr vs. 241.40 mm/yr).
Average Saturation % and Max Wear Rate @ Seam (Dissolution Rate)
for Cell 8
TABLE-US-00003 [0268] Avg Sat'n % Max Wear Rate @ seam(mm/yr) 98.5
109.73 98 241.40
[0269] While various embodiments of the present invention have been
described in detail, it is apparent that modifications and
adaptations of those embodiments will occur to those skilled in the
art. However, it is to be expressly understood that such
modifications and adaptations are within the spirit and scope of
the present invention.
REFERENCE NUMBERS
[0270] Cell 10 [0271] Anode 12 [0272] Cathode 14 [0273] Electrolyte
bath 16 [0274] Metal pad 18 [0275] Cell body 20 [0276] Electrical
bus work 22 [0277] Anode assembly 24 [0278] Current collector bar
40 [0279] Active sidewall 30 [0280] Sidewall 38 (e.g. includes
active sidewall and thermal insulation package) [0281] Bottom 32
[0282] Outer shell 34 [0283] Polarized sidewall 50 [0284] Feed
block 60 [0285] Anodic sidewall 70 [0286] Cathodic sidewall 52
[0287] Bath-air (vapor) interface 26 [0288] Metal-bath interface 28
[0289] Frozen ledge device 80 [0290] Inlet 82 [0291] Outlet 84
[0292] Body 86 [0293] Outer wall 92 (contacts electrolyte) [0294]
Heat absorption section 88 (comprising thermal conducting material
e.g. steel, SiC, graphite sleeve) [0295] Channel 90 [0296] Pump 100
[0297] Energy output 102 [0298] Coolant 96 [0299] Expanded areas
(e.g. fins) 104 [0300] Heat exchanger 98
* * * * *