US4470847A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making titanium, zirconium and hafnium-based metal particles for powder metallurgy
Assignee: Occidental Research Corp
•
Filing: 1982-11-08
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Granted: 1984-09-11
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Expires: 2002-11-08
Abstract
Abstract A process to produce passified Group IVb transition metal based metal particles having a controlled particle size distribution is disclosed which produces particles suitable for metallurgy usage without additional particle size reduction. Such particles are also substantially free of halides and are produced at temperatures considerably below that of arc melting temperatures of Group IVb transition metals and alloys based thereon.
Inventors
- 👤 Robert A. Hard
- 👤 Joseph A. Megy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:24
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/023
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
342 words
A process to produce passified Group IVb transition metal-based metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-zinc alloy comprising: (a) heating a Group IVb transition metal-zinc alloy, which is substantially free of halides, at a temperature between about 500° and about 1150° C. under conditions operative to vaporize and separate zinc therefrom and to produce Group IVb transition metal values which are substantially free of zinc and halides; (b) heating said transition metal values to, or maintaining said transition metal values at, a sintering temperature between about 850° and about 1150° C. under conditions operative to sinter said transition metal values; (c) cooling said sintered transition metal values to a lower temperature between aboout 300° and about 700° C., and simultaneously contacting said sintered transition metal values with hydrogen under conditions operative to hydride and embrittle said sintered transition metal values, thereby forming embrittled transition metal values; (d) comminuting said embrittled transition metal values under a nondeleteriously-reactive atmosphere, to a predetermined particle size distribution thereby forming particles of transition metal values; (e) dehydriding said particles of transition metal values at a temperature between about 400° and about 700° C. under conditions operative to remove essentially all hydrogen values from said particles of transition metal values and to produce dehydrided particles of transition metal values; and (f) contacting said dehydrided particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said dehydrated particles thereby producing passified Group IVb transition metal based metal particles which are substantially free of halides; and (g) said comminuting of said embrittled transition metal values to predetermined particle size distribution in step (d) being operative to cause said passified transition metal based metal particles produced in step (f) to have a particle size distribution such that at least a substantial amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage without further particle size reduction.
Claim 2
Dependent Claim
342 words
A process to produce passified Group IVb transition metal-based metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-zinc alloy comprising: (a) heating a Group IVb transition metal-zinc alloy, which is substantially free of halides, at a temperature between about 500° and about 1150° C. under conditions operative to vaporize and separate zinc therefrom and to produce Group IVb transition metal values which are substantially free of zinc and halides; (b) heating said transition metal values to, or maintaining said transition metal values at, a sintering temperature between about 850° and about 1150° C. under conditions operative to sinter said transition metal values; (c) cooling said sintered transition metal values to a lower temperature between aboout 300° and about 700° C., and simultaneously contacting said sintered transition metal values with hydrogen under conditions operative to hydride and embrittle said sintered transition metal values, thereby forming embrittled transition metal values; (d) comminuting said embrittled transition metal values under a nondeleteriously-reactive atmosphere, to a predetermined particle size distribution thereby forming particles of transition metal values; (e) dehydriding said particles of transition metal values at a temperature between about 400° and about 700° C. under conditions operative to remove essentially all hydrogen values from said particles of transition metal values and to produce dehydrided particles of transition metal values; and (f) contacting said dehydrided particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said dehydrated particles thereby producing passified Group IVb transition metal based metal particles which are substantially free of halides; and (g) said comminuting of said embrittled transition metal values to predetermined particle size distribution in step (d) being operative to cause said passified transition metal based metal particles produced in step (f) to have a particle size distribution such that at least a substantial amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage without further particle size reduction.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein steps (a) and (b) are conducted in the same vessel.
Claim 4
Dependent Claim
17 words
The process of claim 1 wherein steps (a), (b) and (c) are conducted in the same vessel.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein said nondeleteriously-reactive atmosphere used in step (d) is an inert gas.
Claim 6
Dependent Claim
90 words
The process of claim 1 wherein said Group IVb transition metal-zinc alloy is produced from a process comprising fluorinating a Group IVb transition metal-bearing ore, which comprises Group IVb transition metal oxides, by contacting with an alkali metal fluosilicate at a temperature of from about 600° to about 1000° C. to form a fluorinated ore and to convert said Group IVb transition metal oxides to Group IVb transition metal fluorides; and reducing said Group IVb transition metal fluorides with a zinc alloy to produce said Group IVb transition metal-zinc alloy.
Claim 7
Dependent Claim
22 words
The process of claim 4 wherein said Group IVb transition metal-zinc alloy is produced from Group IVb transition metal sponge and zinc.
Claim 8
Dependent Claim
33 words
The process of claim 1 wherein said Group IVb transition metal-zinc alloy is produced from the reduction of a transition metal halide with a metal alloy which comprises a reductant metal and zinc.
Claim 9
Dependent Claim
16 words
The process of claim 1 wherein said Group IVb transition metal-zinc alloy is a titanium-zinc alloy.
Claim 10
Dependent Claim
17 words
The process of claim 1 wherein said heating in step (a) is conducted under a partial vacuum.
Claim 11
Dependent Claim
22 words
The process of claim 1 wherein said heating in step (a) is conducted under a continuous flow of a nondeleteriously-reactive sweep gas.
Claim 12
Dependent Claim
24 words
The process of claim 10 wherein said nondeleteriously-reactive sweep gas is selected from the group consisting of hydrogen, an inert gas, and mixtures thereof.
Claim 13
Dependent Claim
17 words
The process of claim 1 wherein said dehydriding in step (e) is conducted under a partial vacuum.
Claim 14
Dependent Claim
21 words
The process of claim 5 wherein the entire process is conducted at temperatures which are no higher than about 1300° C.
Claim 15
Dependent Claim
431 words
A process to produce passified Group IVb transition metal-based, metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-bearing ore comprising: (a) fluorinating a Group IVb transition metal-bearing ore, which comprises Group IVb transition metal oxides, by contacting said ore with an alkali metal fluosilicate at a temperature of from about 600° to about 1000° C. to form a fluorinated ore and to convert said Group IVb transition metal oxides to Group IVb transition metal fluorides; (b) reducing said Group IVb transition metal fluorides with a zinc alloy to produce a Group IVb transition metal-zinc alloy; (c) heating said Group IVb transition metal-zinc alloy, which is substantially free of halides, at a temperature between about 500° and about 1150° C. under conditions operative to vaporize and separate zinc therefrom and to produce Group IVb transition metal values which are substantially free of zinc and halides; (d) heating said transition metal values to, or maintaining said transition metal values at, a sintering temperature between about 850° and about 1150° C. under conditions operative to sinter said transition metal values; (e) cooling said sintered transition metal values to a lower temperature between about 300° and about 700° C., and simultaneously contacting said sintered transition metal values with hydrogen under conditions operative to hydride and embrittle said sintered transition metal values, thereby forming embrittled transition metal values; (f) comminuting said embrittled transition metal values under a nondeleteriously-reactive atmosphere, to a predetermined particle size distribution thereby forming particles of transition metal values; (g) dehydriding said particles of transition metal values at a temperature between about 400° and about 700° C. under conditions operative to remove essentially all hydrogen values from said particles of transition metal values and to produce dehydrided particles of transition metal values; (h) contacting said dehydrided particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said dehydrided particles thereby producing passified Group IVb transition metal-based, metal particles which are substantially free of halides; and (i) said comminuting of said embrittled transition metal values to predetermined particle size distribution in step (f) being operative to cause said passified transition metal-based, metal particles produced in step (h) to have a particle size distribution such that at least a substantial amount by weight of said passified transition metal-based, metal particles are suitable for powder metallurgy usage without further particle size reduction, and wherein the entire process is conducted at temperatures which are no higher than about 1150° C.
Claim 16
Dependent Claim
431 words
A process to produce passified Group IVb transition metal-based, metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-bearing ore comprising: (a) fluorinating a Group IVb transition metal-bearing ore, which comprises Group IVb transition metal oxides, by contacting said ore with an alkali metal fluosilicate at a temperature of from about 600° to about 1000° C. to form a fluorinated ore and to convert said Group IVb transition metal oxides to Group IVb transition metal fluorides; (b) reducing said Group IVb transition metal fluorides with a zinc alloy to produce a Group IVb transition metal-zinc alloy; (c) heating said Group IVb transition metal-zinc alloy, which is substantially free of halides, at a temperature between about 500° and about 1150° C. under conditions operative to vaporize and separate zinc therefrom and to produce Group IVb transition metal values which are substantially free of zinc and halides; (d) heating said transition metal values to, or maintaining said transition metal values at, a sintering temperature between about 850° and about 1150° C. under conditions operative to sinter said transition metal values; (e) cooling said sintered transition metal values to a lower temperature between about 300° and about 700° C., and simultaneously contacting said sintered transition metal values with hydrogen under conditions operative to hydride and embrittle said sintered transition metal values, thereby forming embrittled transition metal values; (f) comminuting said embrittled transition metal values under a nondeleteriously-reactive atmosphere, to a predetermined particle size distribution thereby forming particles of transition metal values; (g) dehydriding said particles of transition metal values at a temperature between about 400° and about 700° C. under conditions operative to remove essentially all hydrogen values from said particles of transition metal values and to produce dehydrided particles of transition metal values; (h) contacting said dehydrided particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said dehydrided particles thereby producing passified Group IVb transition metal-based, metal particles which are substantially free of halides; and (i) said comminuting of said embrittled transition metal values to predetermined particle size distribution in step (f) being operative to cause said passified transition metal-based, metal particles produced in step (h) to have a particle size distribution such that at least a substantial amount by weight of said passified transition metal-based, metal particles are suitable for powder metallurgy usage without further particle size reduction, and wherein the entire process is conducted at temperatures which are no higher than about 1150° C.
Claim 17
Dependent Claim
306 words
A process to produce passified Group IVb transition metal based metal particles which are substantially free of halides, and which are suitable for power metallurgy usage, from a Group IVb transition metal-zinc alloy comprising: (a) forming a Group IVb transition metal-zinc alloy, which is substantially free of halides, into particles having a particle size distribution of about 90% by weight between about 80 mesh and about 1/4 inch; (b) heating said particles in a zone maintained at a temperature between about 500° and about 1150° C., and simultaneously introducing into said zone a continuous flow of a nondeleteriously-reactive sweep gas, said zone being maintained under conditions operative to vaporize and separate zinc from said transition metal-zinc alloy particles and to produce first particles of Group IVb transition metal values which are substantially free of zinc and halides; (c) heating said first particles to, or maintaining said first particles at, a sintering temperature between about 850° and 1150° C. under conditions operative to sinter said first particles; (d) cooling said sintered first particles to a lower temperature between about ambient temperature and about 200° C.; (e) contacting said cooled sintered first particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said cooled sintered first particles, thereby producing Group IVb passified transition metal-based metal particles which are substantially free of halides; and (f) said forming a transition metal-zinc alloy of a specified particle size distribution in step (a), and said heating of said first particles in step (c) being operative to cause said passified transition metal-based metal particles produced in step (e) to have a particle size distribution such that a significant amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage without additional particle size reduction.
Claim 18
Dependent Claim
306 words
A process to produce passified Group IVb transition metal based metal particles which are substantially free of halides, and which are suitable for power metallurgy usage, from a Group IVb transition metal-zinc alloy comprising: (a) forming a Group IVb transition metal-zinc alloy, which is substantially free of halides, into particles having a particle size distribution of about 90% by weight between about 80 mesh and about 1/4 inch; (b) heating said particles in a zone maintained at a temperature between about 500° and about 1150° C., and simultaneously introducing into said zone a continuous flow of a nondeleteriously-reactive sweep gas, said zone being maintained under conditions operative to vaporize and separate zinc from said transition metal-zinc alloy particles and to produce first particles of Group IVb transition metal values which are substantially free of zinc and halides; (c) heating said first particles to, or maintaining said first particles at, a sintering temperature between about 850° and 1150° C. under conditions operative to sinter said first particles; (d) cooling said sintered first particles to a lower temperature between about ambient temperature and about 200° C.; (e) contacting said cooled sintered first particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said cooled sintered first particles, thereby producing Group IVb passified transition metal-based metal particles which are substantially free of halides; and (f) said forming a transition metal-zinc alloy of a specified particle size distribution in step (a), and said heating of said first particles in step (c) being operative to cause said passified transition metal-based metal particles produced in step (e) to have a particle size distribution such that a significant amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage without additional particle size reduction.
Claim 19
Dependent Claim
16 words
The process of claim 15 wherein steps (b) and (c) are conducted in the same vessel.
Claim 20
Dependent Claim
18 words
The process of claim 15 wherein steps (b), (c), (d) and (e) are conducted in the same vessel.
Claim 21
Dependent Claim
90 words
The process of claim 15 wherein said Group IVb transition metal-zinc alloy is produced from a process comprising fluorinating a Group IVb transition metal-bearing ore, which comprises Group IVb transition metal oxides, by contacting with an alkali metal fluosilicate at a temperature of from about 600° to about 1000° C. to form a fluorinated ore and to convert said Group IVb transition metal oxides to Group IVb transition metal fluorides; and reducing said Group IVb transition metal fluorides with a zinc alloy to produce said Group IVb transition metal-zinc alloy.
Claim 22
Dependent Claim
22 words
The process of claim 15 wherein said Group IVb transition metal-zinc alloy is produced from Group IVb transition metal sponge and zinc.
Claim 23
Dependent Claim
35 words
The process of claim 15 wherein said Group IVb transition metal-zinc alloy is produced from the reduction of a Group IVb transition metal halide with a metal alloy which comprises a reductant metal and zinc.
Claim 24
Dependent Claim
16 words
The process of claim 15 wherein said Group IVb transition metal-zinc alloy is a titanium-zinc alloy.
Claim 25
Dependent Claim
18 words
The process of claim 15 wherein said nondeleteriously-reactive sweep gas used in step (b) is an inert gas.
Claim 26
Dependent Claim
17 words
The process of clam 15 wherein said heating in step (b) is conducted under a partial vacuum.
Claim 27
Dependent Claim
17 words
The process of clam 15 wherein said heating in step (b) is conducted under a partial vacuum.
Claim 28
Dependent Claim
401 words
A process to produce passified Group IVb transition metal-based, metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-bearing ore comprising: (a) fluorinating a Group IVb transition metal-bearing ore, which comprises Group IVb transition metal oxides, by contacting with an alkali metal fluosilicate at a temperature of from about 600° to about 1000° C. to form a fluorinated ore and to convert said Group IVb transition metal oxides to Group IVb transition metal fluorides; (b) reducing said Group IVb transition metal fluorides with a zinc alloy to produce said Group IVb transition metal-zinc alloy which is substantially free of halides; (c) forming said Group IVb transition metal-zinc alloy, which is substantially free of halides, into particles having a particle size distribution of about 90% by weight between about 80 mesh and about 1/4 inch; (d) heating said particles in a zone maintained at a temperature between about 500° and about 1150° C., and simultaneously introducing into said zone a continuous flow of a nondeleteriously-reactive sweep gas, said zone being maintained under conditions operative to vaporize and separate zinc from said transition metal-zinc alloy particles and to produce first particles of Group IVb transition metal values which are substantially free of zinc and halides; (e) heating said first particles to, or, maintaining said first particles at, a sintering temperature between about 850° and 1150° C. under conditions operative to sinter said first particles; (f) cooling said sintered first particles to a lower temperature between about ambient temperature and about 200° C.; (g) contacting said cooled sintered first particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said cooled sintered first particles, thereby producing Group IVb passified transition metal-based, metal particles which are substantially free of halides; and (h) said forming a transition metal-zinc alloy of a specified particle size distribution in step (c), and said heating of said first particles in step (d) being operative to cause said passified transition metal-based, metal particles produced in step (g) to have a particle size distribution such that a significant amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage without additional particle size reduction; and wherein the entire process is conducted at temperatures which are no higher than about 1150° C.
Claim 29
Dependent Claim
401 words
A process to produce passified Group IVb transition metal-based, metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-bearing ore comprising: (a) fluorinating a Group IVb transition metal-bearing ore, which comprises Group IVb transition metal oxides, by contacting with an alkali metal fluosilicate at a temperature of from about 600° to about 1000° C. to form a fluorinated ore and to convert said Group IVb transition metal oxides to Group IVb transition metal fluorides; (b) reducing said Group IVb transition metal fluorides with a zinc alloy to produce said Group IVb transition metal-zinc alloy which is substantially free of halides; (c) forming said Group IVb transition metal-zinc alloy, which is substantially free of halides, into particles having a particle size distribution of about 90% by weight between about 80 mesh and about 1/4 inch; (d) heating said particles in a zone maintained at a temperature between about 500° and about 1150° C., and simultaneously introducing into said zone a continuous flow of a nondeleteriously-reactive sweep gas, said zone being maintained under conditions operative to vaporize and separate zinc from said transition metal-zinc alloy particles and to produce first particles of Group IVb transition metal values which are substantially free of zinc and halides; (e) heating said first particles to, or, maintaining said first particles at, a sintering temperature between about 850° and 1150° C. under conditions operative to sinter said first particles; (f) cooling said sintered first particles to a lower temperature between about ambient temperature and about 200° C.; (g) contacting said cooled sintered first particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said cooled sintered first particles, thereby producing Group IVb passified transition metal-based, metal particles which are substantially free of halides; and (h) said forming a transition metal-zinc alloy of a specified particle size distribution in step (c), and said heating of said first particles in step (d) being operative to cause said passified transition metal-based, metal particles produced in step (g) to have a particle size distribution such that a significant amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage without additional particle size reduction; and wherein the entire process is conducted at temperatures which are no higher than about 1150° C.
Claim 30
Dependent Claim
35 words
The process of claim 15 wherein said Group IVb transition metal-zinc alloy particles formed in step (a) has a particle size distribution of about 90% by weight between about 60 mesh and about 20 mesh.
Claim 31
Dependent Claim
25 words
The process of claim 15 wherein said forming of a Group IVb transition metal-zinc alloy into particles in step (a) comprises comminuting of said alloy.
Claim 32
Dependent Claim
24 words
The process of claim 15 wherein said forming of a Group IVb transition metal-zinc alloy into particles in step (a) comprises casting said alloy.
Claim 33
Dependent Claim
411 words
A process to produce passified Group IVb transition metal-based metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-zinc alloy comprising: (a) forming a Group IVb transition metal-zinc alloy, which is substantially free of halides, into particles having a particle size distribution of about 90% by weight between about 80 mesh and about 1/4 inch; (b) heating said particles in a zone maintained at a temperature between about 500° and about 1150° C., and simultaneously introducing into said zone a continuous flow of a nondeleteriously-reactive sweep gas, said zone being maintained under conditions operative to vaporize and separate zinc from said transition metal-zinc alloy particles and to produce first particles of Group IVb transition metal values which are substantially free of zinc and halides; (c) heating said first particles to, or maintaining said first particles at, a sintering temperature between about 850° and 1150° C. under conditions operative to sinter said first particles; (d) cooling said sintered first particles to a lower temperature between about 300° and about 700° C, and simultaneously contacting said first particles with hydrogen under conditions operative to hydride and embrittle said first particles, thereby forming embrittled transition metal values; (e) comminuting said embrittled transition metal values under a nondeleteriously-reactive atmosphere, to a predetermined particle size distribution thereby forming particles of transition metal values; (f) dehydriding said particles of transition metal values at a temperature between about 400° and 700° C. under conditions operative to remove essentially all hydrogen values from said particles of transition metal values and to produce dehydrided particles of transition metal values; and (g) contacting said dehydrided particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said dehydrided particles thereby producing passified Group IVb transition metal based metal particles which are substantially free of halides; and (h) said forming of a transition metal-zinc alloy of a specified particles size distribution in step (a), said heating of said first particles in step (c), and said comminuting of said embrittled transition metal values to predetermined particle size distribution in step (e) being operative to cause said passified transition metal-based metal particles produced in step (g) to have a particle size distribution such that at least a substantial amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage with further particle size reduction.
Claim 34
Dependent Claim
411 words
A process to produce passified Group IVb transition metal-based metal particles which are substantially free of halides, and which are suitable for powder metallurgy usage, from a Group IVb transition metal-zinc alloy comprising: (a) forming a Group IVb transition metal-zinc alloy, which is substantially free of halides, into particles having a particle size distribution of about 90% by weight between about 80 mesh and about 1/4 inch; (b) heating said particles in a zone maintained at a temperature between about 500° and about 1150° C., and simultaneously introducing into said zone a continuous flow of a nondeleteriously-reactive sweep gas, said zone being maintained under conditions operative to vaporize and separate zinc from said transition metal-zinc alloy particles and to produce first particles of Group IVb transition metal values which are substantially free of zinc and halides; (c) heating said first particles to, or maintaining said first particles at, a sintering temperature between about 850° and 1150° C. under conditions operative to sinter said first particles; (d) cooling said sintered first particles to a lower temperature between about 300° and about 700° C, and simultaneously contacting said first particles with hydrogen under conditions operative to hydride and embrittle said first particles, thereby forming embrittled transition metal values; (e) comminuting said embrittled transition metal values under a nondeleteriously-reactive atmosphere, to a predetermined particle size distribution thereby forming particles of transition metal values; (f) dehydriding said particles of transition metal values at a temperature between about 400° and 700° C. under conditions operative to remove essentially all hydrogen values from said particles of transition metal values and to produce dehydrided particles of transition metal values; and (g) contacting said dehydrided particles with a small amount of a gas selected from the group consisting of oxygen, nitrogen, and mixtures thereof under conditions operative to passify said dehydrided particles thereby producing passified Group IVb transition metal based metal particles which are substantially free of halides; and (h) said forming of a transition metal-zinc alloy of a specified particles size distribution in step (a), said heating of said first particles in step (c), and said comminuting of said embrittled transition metal values to predetermined particle size distribution in step (e) being operative to cause said passified transition metal-based metal particles produced in step (g) to have a particle size distribution such that at least a substantial amount by weight of said passified transition metal-based metal particles are suitable for powder metallurgy usage with further particle size reduction.
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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) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |