Patent US3305302A successfully refreshed from Google Patents.
US3305302A
Expired / Lapsed
US
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Process of beneficiating magnesite
Assignee: General Refractories Co
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Filing: 1963-10-02
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Granted: 1967-02-21
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Expires: 1983-10-02
Abstract
No abstract record available.
Inventors
- 👤 Heuer Russell Pearce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:17
CPC Classifications
C; C01; C01F; C01F11/00; C01F5/00; C01F5/24; C04; C04B; C04B33/00; C04B33/02; C04B33/04; C04B33/06; C04B33/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
A PROCESS OF BENEFICIATING MAGNESIUM CARBONATE CONTAINING A MINOR QUANTITY OF CALCIUM CARBONATE AND HAVING A TOTAL LIME CONTENT WHICH IS APPRECIABLY ABOVE 1% COUNTING THAT OF THE CALCIUM CARBONATE, WHICH COMPRISES TREATING SAID MAGNESIUM CARBONATE WITH SULFURIC ACID IN A CONCENTRATION RANGE BETWEEN 0.05% AND 0.25% BY WEIGHT IN WATER TO PREFERENTIALLY DISSOLVE ENOUGH CALCIUM CARBONATE TO LOWER SAID LIME CONTENT TO BELOW 1% WHILE LEAVING MAGNESIUM CARBONATE, AND THEN SEPARATING THE MAGNESITE RESIDUE REMAINING FROM THE RESULTING SOLUTION.
Claim 2
Dependent Claim
80 words
A PROCESS OF BENEFICIATING MAGNESIUM CARBONATE CONTAINING A MINOR QUANTITY OF CALCIUM CARBONATE AND HAVING A TOTAL LIME CONTENT WHICH IS APPRECIABLY ABOVE 1% COUNTING THAT OF THE CALCIUM CARBONATE, WHICH COMPRISES TREATING SAID MAGNESIUM CARBONATE WITH SULFURIC ACID IN A CONCENTRATION RANGE BETWEEN 0.05% AND 0.25% BY WEIGHT IN WATER TO PREFERENTIALLY DISSOLVE ENOUGH CALCIUM CARBONATE TO LOWER SAID LIME CONTENT TO BELOW 1% WHILE LEAVING MAGNESIUM CARBONATE, AND THEN SEPARATING THE MAGNESITE RESIDUE REMAINING FROM THE RESULTING SOLUTION.
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) | 1970-02-20 | 1970-08-22 | 1971-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-20 | 1974-08-22 | 1975-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-20 | 1978-08-22 | 1979-02-21 | $7700.00 | Window Closed / Lapsed |