Patent US3677366A successfully refreshed from Google Patents.
Patent US3743501A successfully refreshed from Google Patents.
US3743501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zinc recovery process
Assignee: Cyprus Amax Minerals Co
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Filing: 1971-08-17
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Granted: 1973-07-03
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Expires: 1991-08-17
Abstract
Abstract AN IMPROVED PROCESS FOR THE HYDROMETALLURGICAL RECOVERY OF ZINC FROM OXIDIC LEAD-CONTAINING ZINCIFEROUS MATERIAL IS PROVIDED WHEREIN THE IMPROVEMENT RESIDES IN SELECTIVELY LEACHING THE LEAD FROM SAID OXIDIC MATERIAL BY MEANS OF A RELATIVELY DILUTE SOLUTION OF ALKALI METAL HYDROXIDE (E.G. NAOH) AT AN ELEVATED TEMPERATURE AND AT SUPERATMOSPHERIC PRESSURE SUFFICIENT TO REMOVE A SUBSTANTIAL PORTION OF THE LEAD FROM THE OXIDIC MATERIAL AND LEAVE A RESIDUE ENRICHED IN ZINC WHICH MAY THEREAFTER BE RECOVERED IN ANY SUITABLE MANNER.
Inventors
- 👤 H Rajcevic
- 👤 D Cusanelli
- 👤 L Coffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:57
CPC Classifications
C; C22; C22B; C22B19/00; C22B19/20; C22B19/24; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |