US3318718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acid treatment of calcined kaolin
Assignee: Freeport Kaolin Co
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Filing: 1966-02-21
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Granted: 1967-05-09
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Expires: 1986-02-21
Abstract
No abstract record available.
Inventors
- 👤 John W Beamesderfer
- 👤 Horton H Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:38
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/36; C01B33/38; C01B33/40; C04; C04B; C04B33/00; C04B33/02; C04B33/04; C04B33/06; C04B33/30; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/40; C09C1/42; C01P; C01P2002/00; C01P2002/02; C01P2004/00; C01P2004/20; C01P2004/51; C01P2004/80; C01P2006/00; C01P2006/12; C01P2006/21; C01P2006/40; C01P2006/60; C01P2006/80; C01P2006/82
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
170 words
THE METHOD OF PRODUCING A SILICA COATING PAPER PIGMENT WHICH COMPRISES TREATING CALCINED KAOLIN CLAY WITH HOT DILUTE ACID SELECTED FROM A MEMBER OF THE GROUP CONSISTING OF PHOSPHORIC ACID AND A MIXTURE OF PHOSPHORIC ACID AND SULFURIC ACID TO EXTRACT A SUBSTANTIAL AMOUNT OF ALUMINA FROM THE CALCINED CLAY, THE AMOUNT OF PHOSPHORIC ACID IN THE HOT DILUTE ACID BEING AT LEAST APPROXIMATELY EQUAL TO THE ALUMINA CONTENT OF THE CLAY AND THE TOTAL AMOUNT OF HOT DILUTE ACID BEING IN SUFFICIENT EXCESS TO KEEP THE DISSOLVED ALUMINUM SALTS IN SOLUTION, SEPARATING THE RESULTING ACID SOLUTION FROM THE SILICA RESIDUE TO PRODUCE A SILICA PRODUCT CONTAINING ALUMINA OF THE CALCINED CLAY AND PHOSPHORIC ACID IN COMBINED FORM AND CLAY IMPUIRITIES INSOLUBLE IN DILUTE ACID BUT SOLUBLE IN CONCENTRATED SULFURIC ACID, SAID SILICA PRODUCTS HAVING AN ACID SURFACE, A PLATE-LIKE STRUCTURE AND A PARTICLE SIZE DISTRIBUTION SIMILAR TO THAT OF THE CLAY TREATED, AND NEUTRALIZING THE SILICA PRODUCT WITH AN ALKALINE TO FORM A SILICA PRODUCT HAVING AN ALKALINE SURFACE.
Claim 2
Independent Claim
170 words
THE METHOD OF PRODUCING A SILICA COATING PAPER PIGMENT WHICH COMPRISES TREATING CALCINED KAOLIN CLAY WITH HOT DILUTE ACID SELECTED FROM A MEMBER OF THE GROUP CONSISTING OF PHOSPHORIC ACID AND A MIXTURE OF PHOSPHORIC ACID AND SULFURIC ACID TO EXTRACT A SUBSTANTIAL AMOUNT OF ALUMINA FROM THE CALCINED CLAY, THE AMOUNT OF PHOSPHORIC ACID IN THE HOT DILUTE ACID BEING AT LEAST APPROXIMATELY EQUAL TO THE ALUMINA CONTENT OF THE CLAY AND THE TOTAL AMOUNT OF HOT DILUTE ACID BEING IN SUFFICIENT EXCESS TO KEEP THE DISSOLVED ALUMINUM SALTS IN SOLUTION, SEPARATING THE RESULTING ACID SOLUTION FROM THE SILICA RESIDUE TO PRODUCE A SILICA PRODUCT CONTAINING ALUMINA OF THE CALCINED CLAY AND PHOSPHORIC ACID IN COMBINED FORM AND CLAY IMPUIRITIES INSOLUBLE IN DILUTE ACID BUT SOLUBLE IN CONCENTRATED SULFURIC ACID, SAID SILICA PRODUCTS HAVING AN ACID SURFACE, A PLATE-LIKE STRUCTURE AND A PARTICLE SIZE DISTRIBUTION SIMILAR TO THAT OF THE CLAY TREATED, AND NEUTRALIZING THE SILICA PRODUCT WITH AN ALKALINE TO FORM A SILICA PRODUCT HAVING AN ALKALINE SURFACE.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-05-08 | 1970-11-07 | 1971-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-05-08 | 1974-11-07 | 1975-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-05-08 | 1978-11-07 | 1979-05-09 | $7700.00 | Window Closed / Lapsed |