US4454015A
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Composition suitable for use as inert electrode having good electrical conductivity and mechanical properties
Assignee: Alcoa Corp
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Filing: 1982-09-27
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Granted: 1984-06-12
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Expires: 2002-09-27
Abstract
Abstract An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily.
Inventors
- 👤 Siba P. Ray
- 👤 Robert A. Rapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:05
CPC Classifications
C; C25; C25C; C25C7/00; C25C7/02; C25C7/025; C25C3/00; C25C3/06; C25C3/08; C25C3/12
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
112 words
An inert electrode suitable for use in the production of metal by the electrolytic reduction of a metal compound dissolved in a molten salt bath, said inert electrode comprising a composition comprising an interwoven network resulting from the displacement reaction of: (a) a first reactant selected from the class consisting of a metal and a metal compound, and (b) a second reactant consisting of at least one metal compound, said first and second reactants being capable of reacting to form an interwoven network consisting essentially of: (a) at least one metal compound, and (b) a second material selected from the group consisting of free metal, a metal alloy, or a mixture thereof.
Claim 2
Dependent Claim
112 words
An inert electrode suitable for use in the production of metal by the electrolytic reduction of a metal compound dissolved in a molten salt bath, said inert electrode comprising a composition comprising an interwoven network resulting from the displacement reaction of: (a) a first reactant selected from the class consisting of a metal and a metal compound, and (b) a second reactant consisting of at least one metal compound, said first and second reactants being capable of reacting to form an interwoven network consisting essentially of: (a) at least one metal compound, and (b) a second material selected from the group consisting of free metal, a metal alloy, or a mixture thereof.
Claim 3
Dependent Claim
45 words
The inert electrode of claim 1 wherein said first reactant is metallic iron, said second reactant is NiO, and said interwoven network resulting from the displacement reaction of metallic iron with NiO contains interwoven phases of at least one nickel-iron oxide and a nickel-iron alloy.
Claim 4
Dependent Claim
59 words
The inert electrode of claim 1 wherein said first reactant is metallic iron, said second reactant is a mixture of iron oxide and nickel oxide, and said interwoven network resulting from the displacement reaction of metallic iron with the mixture of iron oxide and nickel oxide contains interwoven phases of at least two nickel-iron oxides and a nickel-iron alloy.
Claim 5
Dependent Claim
24 words
The composition of claim 1 wherein said at least one metal compound is selected from the class consisting of Mg, Ca, Zr, and Y.
Claim 6
Dependent Claim
35 words
The inert electrode of claim 1 wherein said metal compound in said interwoven network comprises a plurality of metal compounds, at least one of which includes more than one metal contained in said second material.
Claim 7
Dependent Claim
24 words
The inert electrode of claim 1 wherein at least one of said metal compounds in said interwoven network comprises one or more oxygen-bearing compounds.
Claim 8
Dependent Claim
22 words
The inert electrode of claim 1 wherein at least one of said metal compounds in said interwoven network comprises a metal oxide.
Claim 9
Dependent Claim
24 words
The inert electrode of claim 1 wherein at least one of said metal compounds in said interwoven network comprises a plurality of metal oxides.
Claim 10
Dependent Claim
36 words
The inert electrode of claim 8 wherein more than one metal oxide is present in the composition and at least one of said oxides contains more than one of the metals present in said second material.
Claim 11
Dependent Claim
19 words
The inert electrode of claim 1 wherein 5 to 50 vol.% of the composition consists of said second material.
Claim 12
Dependent Claim
45 words
An inert electrode suitable for use in the production of metal by the electrolytic reduction of a metal compound dissolved in a molten salt, said electrode comprising a composition comprising an interwoven network of at least one nickel-iron oxide with a nickel-iron alloy dispersed therethrough.
Claim 13
Dependent Claim
45 words
An inert electrode suitable for use in the production of metal by the electrolytic reduction of a metal compound dissolved in a molten salt, said electrode comprising a composition comprising an interwoven network of at least one nickel-iron oxide with a nickel-iron alloy dispersed therethrough.
Claim 14
Dependent Claim
19 words
The composition of claim 11 wherein the nickel-iron alloy content is from 5 to 50 vol.% of the composition.
Claim 15
Dependent Claim
13 words
The composition of claim 11 wherein at least two nickel-iron oxides are present.
Claim 16
Dependent Claim
26 words
The composition of claim 3 wherein the nickel-iron oxides have the respective formulas: Ni x Fe 1-x O and Ni x Fe 3-x O 4 .
Claim 17
Dependent Claim
37 words
The composition of claim 14 wherein the ratios of alloy and oxides are: 5 to 50 vol.% alloy, 0 to 30 vol.% Ni x Fe 1-x O and the balance Ni x Fe 3-x O 4 .
Claim 18
Dependent Claim
18 words
The composition of claim 15 wherein the alloy content is from 15 to 25 vol.% of the composition.
Claim 19
Dependent Claim
67 words
An inert electrode suitable for use in the production of metal by electrolytic reduction of a metal compound dissolved in a molten salt comprising a displacement reaction composition comprising a mixture of nickel-iron oxides and nickel-iron alloy interdispersed to form an interwoven network of oxide and alloy to provide an electrode material characterized by chemical inertness, good electrical conductivity and mechanical strength including resistance to thermal shock.
Claim 20
Dependent Claim
67 words
An inert electrode suitable for use in the production of metal by electrolytic reduction of a metal compound dissolved in a molten salt comprising a displacement reaction composition comprising a mixture of nickel-iron oxides and nickel-iron alloy interdispersed to form an interwoven network of oxide and alloy to provide an electrode material characterized by chemical inertness, good electrical conductivity and mechanical strength including resistance to thermal shock.
Claim 21
Dependent Claim
45 words
The composition of claim 17 wherein said mixture consists essentially of nickel-iron compounds and nickel-iron alloy and at least one compound selected from the class consisting of compounds of Al, Mg, Ca, Co, Si, Sn, Ti, Cr, Mn, Zr, Cu, Nb, Ta, Li and Y.
Claim 22
Dependent Claim
17 words
The composition of claim 17 wherein at least one of said metal compounds is an oxygen-bearing compound.
Claim 23
Dependent Claim
16 words
The composition of claim 19 wherein at least one of said oxygen-bearing compounds is an oxide.
Claim 24
Dependent Claim
41 words
The composition of claim 20 wherein said nickel-iron alloy comprises 10 to 35 vol.% and said nickel-iron oxides comprise 0 to 30 vol.% Ni x Fe 1-x O with the balance Ni y Fe 3-y O 4 where 0<x or y<1.0.
Claim 25
Dependent Claim
29 words
The composition of claim 21 wherein the oxides and alloy are the displacement reaction product of reacting metallic iron with iron oxide and nickel oxide at an elevated temperature.
Claim 26
Dependent Claim
20 words
The composition of claim 22 wherein the reactants are sintered at a temperature above 900° C. in an inert atmosphere.
Claim 27
Dependent Claim
21 words
The composition of claim 23 wherein the reactants are sintered at a temperature in the range of 900° to 1500° C.
Claim 28
Dependent Claim
37 words
The composition of claim 24 wherein the reactants consist essentially of NiO, metallic iron and one or more iron oxides selected from the class consisting of FeO, Fe 2 O 3 and Fe 3 O 4 .
Claim 29
Dependent Claim
49 words
The composition of claim 25 wherein the reactants produce, after sintering, a displacement reaction product consisting essentially of about 8 to 10 vol.% Ni x Fe 1-x O, 20 to 22 vol.% nickel-iron alloy and 68 to 70 vol.% Ni y Fe 3-y O 4 where 0<x or y<1.
Claim 30
Dependent Claim
25 words
The composition of claim 26 wherein the weight ratio of nickel to iron in the alloy is approximately in the range of 9:1 to 99:1.
Claim 31
Dependent Claim
9 words
The composition of claim 26 wherein 0.6<x<1 and 0.7<y<1.
Claim 32
Dependent Claim
66 words
An inert electrode comprising a composition consisting essentially of the displacement reaction products of initial reactants provided in a mix comprised of a metal and at least one metal compound, the metal being present in the mix from about 5 to 35 wt.%, the reactants being capable of forming by a displacement reaction an interwoven network of at least one metal compound and a metal alloy.
Claim 33
Dependent Claim
66 words
An inert electrode comprising a composition consisting essentially of the displacement reaction products of initial reactants provided in a mix comprised of a metal and at least one metal compound, the metal being present in the mix from about 5 to 35 wt.%, the reactants being capable of forming by a displacement reaction an interwoven network of at least one metal compound and a metal alloy.
Claim 34
Dependent Claim
19 words
The electrode composition in accordance with claim 29 wherein the metal is present from about 5 to 30 wt.%.
Claim 35
Dependent Claim
15 words
The electrode composition in accordance with claim 29 wherein the metal is iron and nickel.
Claim 36
Dependent Claim
15 words
The electrode composition in accordance with claim 29 wherein the compound is a metal oxide.
Claim 37
Dependent Claim
17 words
The electrode composition in accordance with claim 32 wherein the metal oxide is iron oxide and NiO.
Claim 38
Dependent Claim
19 words
The electrode composition in accordance with claim 33 wherein the iron oxide is present from 0 to 25 wt.%.
Claim 39
Dependent Claim
20 words
The electrode composition in accordance with claim 33 wherein the metal oxide is present from about 50 to 70 wt.%.
Claim 40
Dependent Claim
70 words
An inert electrode comprising the reaction products of initial reactions provided in a mix comprised of 5 to 30 wt.% iron; 0 to 25 wt.% Fe 3 O 4 ; 50 to 70 wt.% NiO and 0 to 35 wt.% of one or more additional metal compounds, the reactants being capable of forming by a displacement reaction an interwoven network of at least one metal oxide and a metal alloy.
Claim 41
Dependent Claim
70 words
An inert electrode comprising the reaction products of initial reactions provided in a mix comprised of 5 to 30 wt.% iron; 0 to 25 wt.% Fe 3 O 4 ; 50 to 70 wt.% NiO and 0 to 35 wt.% of one or more additional metal compounds, the reactants being capable of forming by a displacement reaction an interwoven network of at least one metal oxide and a metal alloy.
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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) | 1987-06-12 | 1987-12-12 | 1988-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-12 | 1991-12-12 | 1992-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-12 | 1995-12-12 | 1996-06-12 | $7700.00 | Window Closed / Lapsed |