US3986978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing spheroidal silica-alumina particles
Assignee: Honeywell UOP LLC
•
Filing: 1974-12-17
•
Granted: 1976-10-19
•
Expires: 1994-12-17
Abstract
Abstract An insoluble basic aluminum sulfate characterized by an SO 3 /Al 2 O 3 mole ratio of from about 0.6 to about 0.4 and a particle size of from about 1 to about 10 microns is commingled with acidic silica sol to form a stable suspension which is convertible to spheroidal particles by the oil-drop method.
Inventors
- 👤 Edward Michalko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:53
CPC Classifications
B; B01; B01J; B01J2/00; B01J2/02; B01J2/06; B01J2/08; B01J21/00; B01J21/02; B01J21/04; B01J35/00; B01J35/50; B01J35/51
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
177 words
A method of manufacturing spheroidal silica-alumina particles which comprises: a. precipitating basic aluminum sulfate from a common aqueous solution of aluminum sulfate and ammonium hydroxide having a pH of from about 5.5 to about 6.5, the precipitated basic aluminum sulfate having an SO 3 /Al 2 O 3 mole ratio of from about 0.6 to about 0.4 and a particle size of from about 1 to about 10 microns; b. suspending said precipitated basic aluminum sulfate in a silica sol having a pH of from about 1 to about 3; c. dispersing the resultant suspension as droplets in a hot, water-immiscible, suspending media, and retaining the droplets therein until they set to firm hydrogel particles; d. aging the hydrogel particles for a period of from about 1/2 to about 2 hours at a temperature of from about 50° C to about 105° C in an aqueous alkaline solution; and e. thereafter washing and drying the aged particles and then calcining the same in an oxidizing atmosphere at a temperature of from about 425° to about 750° C.
Claim 2
Independent Claim
177 words
A method of manufacturing spheroidal silica-alumina particles which comprises: a. precipitating basic aluminum sulfate from a common aqueous solution of aluminum sulfate and ammonium hydroxide having a pH of from about 5.5 to about 6.5, the precipitated basic aluminum sulfate having an SO 3 /Al 2 O 3 mole ratio of from about 0.6 to about 0.4 and a particle size of from about 1 to about 10 microns; b. suspending said precipitated basic aluminum sulfate in a silica sol having a pH of from about 1 to about 3; c. dispersing the resultant suspension as droplets in a hot, water-immiscible, suspending media, and retaining the droplets therein until they set to firm hydrogel particles; d. aging the hydrogel particles for a period of from about 1/2 to about 2 hours at a temperature of from about 50° C to about 105° C in an aqueous alkaline solution; and e. thereafter washing and drying the aged particles and then calcining the same in an oxidizing atmosphere at a temperature of from about 425° to about 750° C.
Claim 3
Dependent Claim
31 words
The method of claim 1 further characterized in that said basic aluminum sulfate is utilized in an amount to provide a silica-alumina product comprising up to about 60 wt. percent alumina.
Claim 4
Dependent Claim
18 words
The method of claim 1 further characterized in that said aqueous alkaline solution is an aqueous ammoniacal solution.
Claim 5
Dependent Claim
31 words
The method of claim 1 further characterized in that said suspension is dispersed as droplets in an oil bath maintained at a temperature of from about 50° to about 105° C.
Claim 6
Dependent Claim
35 words
The method of claim 1 further characterized in that said aged hydrogel particles are washed in aqueous ammoniacal solution and then water-washed to reduce the sulfate content thereof to less than about 0.5 wt. percent.
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) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |