Patent US4356028A successfully refreshed from Google Patents.
US4356028A
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US
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In situ phosphorus addition to tantalum
Assignee: TANTALUM PRODUCTION Inc A DE CORP
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Filing: 1981-08-24
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Granted: 1982-10-26
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Expires: 2001-08-24
Abstract
Abstract During the method of preparing tantalum powder from a tantalum rich solution in an organic solvent in which a tantalum salt is precipitated from the tantalum rich solvent and the tantalum salt is reduced to metalic tantalum by an alkali metal, a phosphorus-containing material is added to either the precipitated step or the reduction step or both.
Inventors
- 👤 Victor T. Bates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:53
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/20; C22B34/24; B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
165 words
In the process for making tantalum powder wherein ( 1) a tantalum-containing material is digested in hydrofluoric acid to dissolve tantalum values and other materials in a hydrofluoric acid solution, (2) tantalum is separated from other materials by extraction of said solution with an organic solvent in a liquid-liquid solvent extraction process and a tantalum-rich solution is recovered therefrom, (3) said tantalum-rich solution is treated to precipitate a tantalum salt, (4) said tantalum salt is reduced to metallic tantalum by an alkali metal, and (5) metallic tantalum is recovered from said reduction step in the form of a powder, the improvement wherein a phosphorus-containing material is added to at least one of said steps (3) and (4) in an amount of at least 5 parts of elemental phosphorus per million parts of elemental tantalum at the step of said addition and an amount to provide from about 2 to about 400 parts of elemental phosphorus per million parts of elemental tantalum in the final powder.
Claim 2
Dependent Claim
165 words
In the process for making tantalum powder wherein ( 1) a tantalum-containing material is digested in hydrofluoric acid to dissolve tantalum values and other materials in a hydrofluoric acid solution, (2) tantalum is separated from other materials by extraction of said solution with an organic solvent in a liquid-liquid solvent extraction process and a tantalum-rich solution is recovered therefrom, (3) said tantalum-rich solution is treated to precipitate a tantalum salt, (4) said tantalum salt is reduced to metallic tantalum by an alkali metal, and (5) metallic tantalum is recovered from said reduction step in the form of a powder, the improvement wherein a phosphorus-containing material is added to at least one of said steps (3) and (4) in an amount of at least 5 parts of elemental phosphorus per million parts of elemental tantalum at the step of said addition and an amount to provide from about 2 to about 400 parts of elemental phosphorus per million parts of elemental tantalum in the final powder.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein said phosphorus-containing material is added to said tantalum-rich solution prior to the precipitation of said tantalum salt therefrom.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein said phosphorus-containing material is added to said tantalum-rich solution during the precipitation of said tantalum salt therefrom.
Claim 5
Dependent Claim
26 words
The method of claim 1 wherein said phosphorus-containing material is charged with said tantalum salt into a reaction vessel into which an alkali metal is added.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein said phosphorus-containing material is an inorganic phosphorus-containing salt.
Claim 7
Dependent Claim
14 words
The method of claim 5 wherein said phosphorus-containing salt is an alkali metal salt.
Claim 8
Dependent Claim
13 words
The method of claim 5 wherein said salt is free of metallic ions.
Claim 9
Dependent Claim
21 words
The method of claim 1 wherein said addition of phosphorus-containing material comprises the only addition of phosphorus-containing material to said tantalum.
Claim 10
Dependent Claim
20 words
The method of claim 1 wherein additional phosphorus-containing material is added to said tantalum powder subsequent to said step (5).
Claim 11
Dependent Claim
10 words
The tantalum powder produced by the method of claim 1.
Claim 12
Dependent Claim
10 words
The tantalum powder produced by the method of claim 8.
Claim 13
Dependent Claim
10 words
The tantalum powder produced by the method of claim 9.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |