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Patent US3529957A successfully refreshed from Google Patents.
US3529957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of elemental sulphur and iron from iron sulphides
Assignee: Viridian Inc Canada
•
Filing: 1968-02-09
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Granted: 1970-09-22
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Expires: 1988-02-09
Abstract
No abstract record available.
Inventors
- 👤 Wasyl Kunda
- 👤 Herbert Arthur Hancock
- 👤 Nicolas Zubryckyj
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:41
CPC Classifications
C; C22; C22B; C22B1/00; C22B1/11; C22B1/02; C22B1/14; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2130278A
Cited
US3088820A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-09-21 | 1974-03-23 | 1974-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-09-21 | 1978-03-23 | 1978-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-09-21 | 1982-03-23 | 1982-09-22 | $7700.00 | Window Closed / Lapsed |