US4156635A
Expired / Lapsed
US
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Electrolytic method for the production of lithium using a lithium-amalgam electrode
Assignee: United States Department of Energy
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Filing: 1978-03-29
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Granted: 1979-05-29
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Expires: 1998-03-29
Abstract
Abstract A method for recovering lithium from its molten amalgam by electrolysis of the amalgam in an electrolytic cell containing as a molten electrolyte a fused-salt consisting essentially of a mixture of two or more alkali metal halides, preferably alkali metal halides selected from lithium iodide, lithium chloride, potassium iodide and potassium chloride. A particularly suitable molten electrolyte is a fused-salt consisting essentially of a mixture of at least three components obtained by modifying an eutectic mixture of LiI-KI by the addition of a minor amount of one or more alkali metal halides. The lithium-amalgam fused-salt cell may be used in an electrolytic system for recovering lithium from an aqueous solution of a lithium compound, wherein electrolysis of the aqueous solution in an aqueous cell in the presence of a mercury cathode produces a lithium amalgam. The present method is particularly useful for the regeneration of lithium from the aqueous reaction products of a lithium-water-air battery.
Inventors
- 👤 John F. Cooper
- 👤 Oscar H. Krikorian
- 👤 Robert V. Homsy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:39
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
41 words
A method for recovering lithium from a molten lithium amalgam which comprises employing said amalgam as an anode in an electrolysis cell which contains as molten electrolyte a fused-salt consisting essentially of a mixture of at least two alkali metal halides.
Claim 2
Independent Claim
41 words
A method for recovering lithium from a molten lithium amalgam which comprises employing said amalgam as an anode in an electrolysis cell which contains as molten electrolyte a fused-salt consisting essentially of a mixture of at least two alkali metal halides.
Claim 3
Dependent Claim
42 words
The method as in claim 1 wherein the alkali metal halides are formed from ions selected from Cs + , Li + , Na + , K + , F - , Cl - , Br - , and I - .
Claim 4
Dependent Claim
23 words
The method as in claim 2 wherein the alkali metal halides are selected from lithium iodide, lithium chloride, potassium iodide and potassium chloride.
Claim 5
Dependent Claim
44 words
The method as in claim 2 wherein the fused-salt is a mixture of at least three alkali metal halides and consists essentially of a major proportion of a lithium iodide-potassium iodide mixture and a minor amount of at least one other alkali metal halide.
Claim 6
Dependent Claim
22 words
The method as in claim 4 wherein the other alkali metal halide is selected from lithium chloride, potassium chloride, and mixtures thereof.
Claim 7
Dependent Claim
32 words
The method as in claim 5 wherein the fused salt consists essentially of about 8 mole percent lithium chloride, about 42 mole percent potassium iodide, and about 50 mole percent lithium iodide.
Claim 8
Independent Claim
125 words
A method for the production of lithium which comprises: maintaining in a first electrolysis cell an aqueous solution of a lithium compound in contact with an anode and an amalgam of lithium as cathode; maintaining in a second electrolysis cell a fused-salt which is molten at cell operating temperature and consists essentially of a mixture of at least two alkali halides as molten electrolyte in contact with a lithium amalgam and a cathode, the cathodic amalgam of the first cell serving as anodic amalgam of the second cell; and passing an electric current through the first and second cells by electrically contacting the anode of the first cell and the cathode of the second cell, thereby producing lithium at the cathode of the second cell.
Claim 9
Independent Claim
125 words
A method for the production of lithium which comprises: maintaining in a first electrolysis cell an aqueous solution of a lithium compound in contact with an anode and an amalgam of lithium as cathode; maintaining in a second electrolysis cell a fused-salt which is molten at cell operating temperature and consists essentially of a mixture of at least two alkali halides as molten electrolyte in contact with a lithium amalgam and a cathode, the cathodic amalgam of the first cell serving as anodic amalgam of the second cell; and passing an electric current through the first and second cells by electrically contacting the anode of the first cell and the cathode of the second cell, thereby producing lithium at the cathode of the second cell.
Claim 10
Dependent Claim
42 words
The method as in claim 7 wherein the alkali metal halides are formed from ions selected from Cs + , Li + , Na + , K + , F - , Cl - , Br - , and I - .
Claim 11
Dependent Claim
23 words
The method as in claim 8 wherein the alkali metal halides are selected from lithium iodide, lithium chloride, potassium iodide, and potassium chloride.
Claim 12
Dependent Claim
44 words
The method as in claim 8 wherein the fused-salt is a mixture of at least three alkali metal halides and consists essentially of a major proportion of a lithium iodide-potassium iodide mixture and a minor amount of at least one other alkali metal halide.
Claim 13
Dependent Claim
24 words
The method as in claim 10 wherein the mixture of at least three alkali metal halides has a melting point below about 250° C.
Claim 14
Dependent Claim
22 words
The method as in claim 10 wherein the other alkali metal halide is selected from lithium chloride, potassium chloride, and mixtures thereof.
Claim 15
Dependent Claim
31 words
The method as in claim 12 wherein the fused-salt consists essentially of about 8 mole percent lithium chloride, about 42 mole percent potassium iodide, and about 50 mole percent lithium iodide.
Claim 16
Dependent Claim
13 words
The method as in claim 7 wherein the lithium compound is lithium hydroxide.
Claim 17
Dependent Claim
51 words
The method as in claim 7 further including the step of circulating the lithium amalgam between the first cell and the second cell in a manner so as to provide countercurrent heat transfer between an amalgam stream flowing to the first cell and an amalgam stream flowing to the second cell.
References Cited (Backward Citations)
US2148404A
Cited
US2234967A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-28 | 1982-11-27 | 1983-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-28 | 1986-11-27 | 1987-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-28 | 1990-11-27 | 1991-05-29 | $7700.00 | Window Closed / Lapsed |