Patent US3218159A successfully refreshed from Google Patents.
US3218159A
Expired / Lapsed
US
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Manufacture of pure bismuth
Assignee: LA LES PRODUITS SEMI-CONDUCTEURS Ste
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Filing: 1961-04-10
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Granted: 1965-11-16
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Expires: 1981-04-10
Abstract
No abstract record available.
Inventors
- 👤 Champ Roger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:26
CPC Classifications
C; C22; C22B; C22B30/00; C22B30/06; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A METHOD OF PREPARING VERY PURE BISMUTH WHICH COMPRISES SUBJECTING BISMUTH CONTAINING ON THE ORDER OF .5% OF IMPURITIES BY WEIGHT TO A VACUUM ON THE ORDER OF 10**-2 TO 10**-4 MM. HG, HEATING THE BISMUTH PROGRESSIVELY THROUGH THE VOLATILIZING RANGE OF IMPURITIES OF THE GROUP CONSISTING OF ARSENIC, SULFUR, TELLURIUM, MAGNESIUM AND ZINC AND SEPARATING THE VOLATILIZED IMPURITIES FROM THE BISMUTH-CONTAINING SOLID RESIDUE, ARRESTING THE RISE IN TEMPERATURE AT ABOUT 600*C., AND REDUCING THE TEMPERATURE TO ABOUT 540*C. FOR ABOUT A HALF HOUR, INCREASING THE PRESSURE BY ADDING INERT GAS TO ATTAIN ABOUT 4 MM. HG, RAISING THE TEMPERATURE TO ABOUT 750*, AND CONDENSING THE BI AS IT DISTILLS.
Claim 2
Independent Claim
110 words
A METHOD OF PREPARING VERY PURE BISMUTH WHICH COMPRISES SUBJECTING BISMUTH CONTAINING ON THE ORDER OF .5% OF IMPURITIES BY WEIGHT TO A VACUUM ON THE ORDER OF 10**-2 TO 10**-4 MM. HG, HEATING THE BISMUTH PROGRESSIVELY THROUGH THE VOLATILIZING RANGE OF IMPURITIES OF THE GROUP CONSISTING OF ARSENIC, SULFUR, TELLURIUM, MAGNESIUM AND ZINC AND SEPARATING THE VOLATILIZED IMPURITIES FROM THE BISMUTH-CONTAINING SOLID RESIDUE, ARRESTING THE RISE IN TEMPERATURE AT ABOUT 600*C., AND REDUCING THE TEMPERATURE TO ABOUT 540*C. FOR ABOUT A HALF HOUR, INCREASING THE PRESSURE BY ADDING INERT GAS TO ATTAIN ABOUT 4 MM. HG, RAISING THE TEMPERATURE TO ABOUT 750*, AND CONDENSING THE BI AS IT DISTILLS.
References Cited (Backward Citations)
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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) | 1968-11-15 | 1969-05-17 | 1969-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-15 | 1973-05-17 | 1973-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-15 | 1977-05-17 | 1977-11-16 | $7700.00 | Window Closed / Lapsed |