US2894809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of recovering mineral values
Assignee: Individual
•
Filing: 1955-07-06
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Granted: 1959-07-14
•
Expires: 1975-07-06
Abstract
No abstract record available.
Inventors
- 👤 Robert F Mccullough
- 👤 Joseph B Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:33
CPC Classifications
C; C22; C22B; C22B60/00; C22B60/02; C22B60/0204; C22B60/0217; C22B60/0221; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/06; C01F7/0673; C22B60/0208; C22B60/0252; C22B60/026
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
IN A METHOD OF RECOVERING MINERAL VALUES FROM LOW GRADE PHOSPHATE ORE, THE STEPS WHICH COMPRISE ACIDULATING THE ORE WITH SULFURIC ACID UNDER CONDITIONS OF STRONG AGITATION TO FORM A PASTRY SLURRY, HEAT TREATING THE ACID MIX AT TEMPERATURES IN THE RANGE BETWEEN ABOUT 250*C. AND ABOUT 700*C. WHILE DRYING THE ACID MIX TO PRODUCE DRY
Claim 2
Dependent Claim
56 words
IN A METHOD OF RECOVERING MINERAL VALUES FROM LOW GRADE PHOSPHATE ORE, THE STEPS WHICH COMPRISE ACIDULATING THE ORE WITH SULFURIC ACID UNDER CONDITIONS OF STRONG AGITATION TO FORM A PASTRY SLURRY, HEAT TREATING THE ACID MIX AT TEMPERATURES IN THE RANGE BETWEEN ABOUT 250*C. AND ABOUT 700*C. WHILE DRYING THE ACID MIX TO PRODUCE DRY
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) | 1962-07-13 | 1963-01-12 | 1963-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-07-13 | 1967-01-12 | 1967-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-07-13 | 1971-01-12 | 1971-07-14 | $7700.00 | Window Closed / Lapsed |