US3607777A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing microspheroidal desiccant silica gel
Assignee: WR Grace and Co
•
Filing: 1968-06-18
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Granted: 1971-09-21
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Expires: 1988-06-18
Abstract
Abstract An aqueous alkali metal silicate solution is partially neutralized with a mineral acid until a pH of about 9.6-10.9 is reached. When a soft gel has formed, the mixture is vigorously agitated to obtain a fine slurry, and more mineral acid is added until a pH of about 0.5-3.0 is reached. The resultant slurry is then spray dried and washed. After drying at about 200* C., product particles of desiccant silica gel having average particle sizes ranging from 10 to 100 microns, a surface area of about 650-950 m.2/g., and a pore volume of 0.35-0.8 cc./g. are obtained.
Inventors
- 👤 Milton E Winyall
- 👤 Ellsworth G Acker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:42
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/152; C01B33/154
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
20 words
The process of claim 1 wherein said aqueous solution of alkali metal silicate contains about 5-22 percent silica by weight.
Claim 2
Dependent Claim
13 words
The process of claim 2 wherein said alkali metal silicate is sodium silicate.
Claim 3
Dependent Claim
16 words
The process of claim 3 wherein said acidic silica slurry is dried in about 1-5 seconds.
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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |