US2827372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of extracting gold
Assignee: Lakefield Research Ltd
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Filing: 1957-04-19
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Granted: 1958-03-18
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Expires: 1977-04-19
Abstract
No abstract record available.
Inventors
- 👤 John W Britton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:13
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/08
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
74 words
IN THE REMOVAL OF GOLD FROM IRON-CONTAING GOLD BEARING MATERIAL WHEREIN THE MATERIAL IS ROASTED AND TREATED WITH GOLD-DISSOLVING REAGENT, THE METHOD WHICH COMPRISES HEATING THE RESIDUE FROM THE GOLD-DISSOLVING TREATMENT TO A TEMPERATURE OF AT LEAST 1650* F. BUT HIGHER THAN THE MAXIMUM ROASTING TEMPERATURE, COOLING AND FINELY DIVIDING THE SO HEATED RESIDUA TO CAUSE AT LEAST 90% OF IT TO PASS THROUGH A 200 MESH SCREEN AND TREATING WITH A GOLD-DISSOLVING REAGENT
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) | 1961-03-17 | 1961-09-16 | 1962-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-17 | 1965-09-16 | 1966-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-17 | 1969-09-16 | 1970-03-18 | $7700.00 | Window Closed / Lapsed |