US4285724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous production of finely divided zirconium powder
Assignee: Alcoa Corp
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Filing: 1979-11-15
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Granted: 1981-08-25
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Expires: 1999-11-15
Abstract
Abstract Process for production of finely divided zirconium powder by reaction of solid magnesium with ZrCl4 in a molten salt bath maintained at a temperature below the melting point of magnesium. A preferred salt bath contains about 8 mole % ZrCl4 in an equimolar mixture of KCl and NaCl and is maintained at about 625 DEG C. Gaseous ZrCl4 and solid magnesium are continuously fed to a lower portion of the bath, the bath is continuously agitated, and bath containing MgCl2 is continuously removed. Zirconium powder recovered from the bath is generally spherical with a median particle size of about 2.2 mu m and is suitable for use in rapid rise time thermal batteries.
Inventors
- 👤 Aaron J. Becker
- 👤 Don R. Careatti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:26
CPC Classifications
H; H01; H01M; H01M6/00; H01M6/30; H01M6/36; B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/24; B22F9/28; C; C22; C22B; C22B34/00; C22B34/10; C22B34/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
123 words
A process for production of finely divided Zr powder by reaction of ZrCl 4 with Mg, comprising the steps of (a) providing a molten salt bath comprising about 5 to 95 mole % ZrCl 4 , about 0 to 45 mole % MgCl 2 , and the remainder KCl, NaCl or mixtures of KCl and NaCl; (b) maintaining the bath at a temperature greater than the solidus temperature of the bath and less than the melting point of Mg, said temperature being about 540° to 649° C.; (c) feeding gaseous ZrCl 4 to a lower portion of the bath; (d) reacting the ZrCl 4 with solid Mg to form MgCl 2 and Zr powder; and (e) separating the Zr powder from the bath.
Claim 2
Dependent Claim
123 words
A process for production of finely divided Zr powder by reaction of ZrCl 4 with Mg, comprising the steps of (a) providing a molten salt bath comprising about 5 to 95 mole % ZrCl 4 , about 0 to 45 mole % MgCl 2 , and the remainder KCl, NaCl or mixtures of KCl and NaCl; (b) maintaining the bath at a temperature greater than the solidus temperature of the bath and less than the melting point of Mg, said temperature being about 540° to 649° C.; (c) feeding gaseous ZrCl 4 to a lower portion of the bath; (d) reacting the ZrCl 4 with solid Mg to form MgCl 2 and Zr powder; and (e) separating the Zr powder from the bath.
Claim 3
Dependent Claim
38 words
The process of claim 1 wherein the bath initially contains essentially no MgCl 2 , further comprising (g) removing MgCl 2 from the bath to maintain the concentration of MgCl 2 in the bath below one mole %.
Claim 4
Dependent Claim
25 words
The process of claim 1 wherein the Mg is fed to the bath together with an equimolar quantity of KCl or NaCl or mixtures thereof.
Claim 5
Dependent Claim
22 words
The process of claim 1 further comprising continuously agitating the bath to promote reaction between the solid Mg and ZrCl 4 .
Claim 6
Dependent Claim
20 words
The process of claim 1 wherein the Zr powder has a median particle size of less than about 4 μm.
Claim 7
Dependent Claim
24 words
The process of claim 1 wherein the gaseous ZrCl 4 has a gas residence time of about 1.1 minute or less in the bath.
Claim 8
Dependent Claim
24 words
The process of claim 1 wherein the gaseous ZrCl 4 and the solid Mg are both fed to a lower portion of the bath.
Claim 9
Dependent Claim
67 words
A process for continuous production of finely divided Zr powder, comprising the process of claim 1 wherein gaseous ZrCl 4 and solid Mg are both fed continuously to a lower portion of the bath, the bath initially contains essentially no MgCl 2 , MgCl 2 is continuously removed from the bath to maintain the MgCl 2 concentration below one mole %, and the bath is continuously agitated.
Claim 10
Dependent Claim
19 words
The process of claim 1 wherein the Zr powder has a particle size of about 12.68 μm or less.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein the solid Mg is finely divided.
Claim 12
Dependent Claim
41 words
The process of claim 1 wherein the bath comprises about 40 to 50 mole % KCl, about 40 to 50 mole % NaCl, about 5 to 20 mole % ZrCl 4 , and less than one mole % MgCl 2 .
Claim 13
Dependent Claim
39 words
The process of claim 11 wherein the bath consists essentially of about 46 mole % KCl, about 46 mole % NaCl, and about 8 mole % ZrCl 4 , and is maintained at a temperature of about 625° C.
References Cited (Backward Citations)
US2214211A
Cited
US2861791A
Cited
US2839385A
Cited
GB810428A
Cited
US2942969A
Cited
US3692294A
Cited
SU558059A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-24 | 1985-02-23 | 1985-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-24 | 1989-02-23 | 1989-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-24 | 1993-02-23 | 1993-08-25 | $7700.00 | Window Closed / Lapsed |