US4175022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic cell bottom barrier formed from expanded graphite
Assignee: Graftech Technology LLC
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Filing: 1977-04-25
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Granted: 1979-11-20
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Expires: 1997-04-25
Abstract
Abstract The thermal insulation in the bottom of an electrolytic cell for the production of metal by electrolysis of metal ore or ore derivatives is protected from attack by the corrosive elements in the electrolytic bath. The protection is provided by a layer of graphite sheet formed from expanded graphite which is placed on top of the insulation. Preferably the graphite rests on a thin steel sheet.
Inventors
- 👤 Jostein J. Vadla
- 👤 Harold J. Wilder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:57
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/08; C25C3/085; C25C7/00; C25C7/005; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249967; Y10T428/30
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
62 words
In an electrolytic cell, for the electrolytic reduction of metal ores, said cell having a steel shell and a lining of insulation on the bottom and sides thereof, the improvement consisting of a lining on the bottom of said shell comprising thermal insulation and a protective layer of at least one graphite sheet formed from expanded graphite on top of said insulation.
Claim 2
Dependent Claim
62 words
In an electrolytic cell, for the electrolytic reduction of metal ores, said cell having a steel shell and a lining of insulation on the bottom and sides thereof, the improvement consisting of a lining on the bottom of said shell comprising thermal insulation and a protective layer of at least one graphite sheet formed from expanded graphite on top of said insulation.
Claim 3
Dependent Claim
73 words
In an electrolytic cell, for the electrolytic reduction of metal ores, said cell having a steel shell and a lining of insulation of the bottom and sides thereof, the improvement consisting of a lining on the bottom of said shell comprising thermal insulation, a steel sheet on top of said insulation and directly resting on top of said steel sheet, a protective layer comprising at least one graphite sheet formed from expanded graphite.
Claim 4
Dependent Claim
73 words
In an electrolytic cell, for the electrolytic reduction of metal ores, said cell having a steel shell and a lining of insulation of the bottom and sides thereof, the improvement consisting of a lining on the bottom of said shell comprising thermal insulation, a steel sheet on top of said insulation and directly resting on top of said steel sheet, a protective layer comprising at least one graphite sheet formed from expanded graphite.
Claim 5
Dependent Claim
15 words
A lining according to claim 1 wherein said thermal insulation comprises a layer of alumina.
Claim 6
Dependent Claim
17 words
A lining according to claim 1 wherein said thermal insulation comprises a layer of fibrous insulating material.
Claim 7
Dependent Claim
16 words
A lining according to claim 1 wherein said thermal insulation comprises a layer of insulating brick.
Claim 8
Dependent Claim
16 words
A lining according to claim 1 wherein said thermal insulation comprises a layer of fire brick.
Claim 9
Dependent Claim
44 words
A lining according to claim 1 wherein said thermal insulation comprises a bottom layer of fibrous insulating material, at least one layer of insulating brick on top of said fibrous insulating material, and a layer of fire brick on top of said insulating brick.
Claim 10
Dependent Claim
24 words
A lining according to claim 1 wherein the graphite sheet in said protective layer has a total thickness of from 5 to 60 mils.
Claim 11
Dependent Claim
24 words
A lining according to claim 1 wherein the graphite sheet in said protective layer has a total thickness of from 15 to 25 mils.
Claim 12
Dependent Claim
26 words
A lining according to claim 1 wherein the graphite sheet in said protective layer has a density of from 20 to 110 pounds per cubic foot.
Claim 13
Dependent Claim
26 words
A lining according to claim 1 wherein the graphite sheet in said protective layer has a density of from 70 to 95 pounds per cubic foot.
Claim 14
Dependent Claim
32 words
A lining according to claim 1 wherein the graphite sheet in said protective layer has a total thickness of about 20 mils. and a density of about 90 pounds per cubic foot.
Claim 15
Dependent Claim
20 words
A lining according to claim 2 wherein the steel sheet in said protective layer is at least 5 mils thick.
Claim 16
Dependent Claim
35 words
A lining according to claim 1 wherein the graphite sheet in said protective layer at the time it is positioned in the bottom of said shell has a reinforcing structure adhered to its top surface.
Claim 17
Dependent Claim
29 words
A lining according to claim 1 wherein the graphite sheet in said protective layer extends part way up the inside of the end walls of said steel outer shell.
Claim 18
Dependent Claim
15 words
A lining according to claim 2 wherein said thermal insulation comprises a layer of alumina.
Claim 19
Dependent Claim
17 words
A lining according to claim 2 wherein said thermal insulation comprises a layer of fibrous insulating material.
Claim 20
Dependent Claim
16 words
A lining according to claim 2 wherein said thermal insulation comprises a layer of insulating brick.
Claim 21
Dependent Claim
16 words
A lining according to claim 2 wherein said thermal insulation comprises a layer of fire brick.
Claim 22
Dependent Claim
44 words
A lining according to claim 2 wherein said thermal insulation comprises a bottom layer of fibrous insulating material, at least one layer of insulating brick on top of said fibrous insulating material, and a layer of fire brick on top of said insulating brick.
Claim 23
Dependent Claim
24 words
A lining according to claim 2 wherein the graphite sheet in said protective layer has a total thickness of from 5 to 60 mils.
Claim 24
Dependent Claim
24 words
A lining according to claim 2 wherein the graphite sheet in said protective layer has a total thickness of from 15 to 25 mils.
Claim 25
Dependent Claim
26 words
A lining according to claim 2 wherein the graphite sheet in said protective layer has a density of from 20 to 110 pounds per cubic foot.
Claim 26
Dependent Claim
26 words
A lining according to claim 2 wherein the graphite sheet in said protective layer has a density of from 70 to 95 pounds per cubic foot.
Claim 27
Dependent Claim
32 words
A lining according to claim 2 wherein the graphite sheet in said protective layer has a total thickness of about 20 mils. and a density of about 90 pounds per cubic foot.
Claim 28
Dependent Claim
35 words
A lining according to claim 2 wherein the graphite sheet in said protective layer at the time it is positioned in the bottom of said shell has a reinforcing structure adhered to its top surface.
Claim 29
Dependent Claim
29 words
A lining according to claim 2 wherein the graphite sheet in said protective layer extends part way up the inside of the end walls of said steel outer shell.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-19 | 1983-05-21 | 1983-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-19 | 1987-05-21 | 1987-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-19 | 1991-05-21 | 1991-11-20 | $7700.00 | Window Closed / Lapsed |