Patent US3853789A successfully refreshed from Google Patents.
US3853789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of macroporous alumina extrudates
Assignee: Individual
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Filing: 1973-03-09
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Granted: 1974-12-10
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Expires: 1993-03-09
Abstract
Abstract Strong, attrition resistant, activated alumina extrudates, suitable for use as adsorbents or catalyst carriers and having large mercury pore volumes due to a combination of microporosity and macroporosity, are prepared by extruding specific proportions and particle size distributions of alumina monohydrate and gamma alumina powders.
Inventors
- 👤 F Ciapetta
- 👤 C Ciapetta
- 👤 J Warthen
- 👤 W Briggs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:35
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/0009; B01J21/00; B01J21/02; B01J21/04; B01J35/00; B01J35/60; B01J35/61; B01J35/615; B01J35/63; B01J35/633; B01J35/635; B01J35/64; B01J35/651; Y; Y10; Y10S; Y10S502/00; Y10S502/50; Y10S502/503
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
A METHOD FOR PREPARING MECHANICALLY STRONG MACROPOROUS ALUMINA EXTRUDATES HAVING A MERCURY PORE VOLUME OF ABOUT 0.3 TO ABOUT 0.7 CC/G WHEREIN 40 TO 100 PERCENT OF THE PORE VOLUME IS CONTAINED IN PORES HAVING A SIZE ABOVE 3500A IN DIAMETER AND A SURFACE AREA OF ABOUT 200 TO 400 M2/G WHICH COMPRISES; A. PREPARING A MIXTURE WHICH COMPRISES: 1. 40 TO 90 PERCENT BY WEIGHT GAMMA ALUMINA POWDER HAVING A PARTICLE SIZE RANGE OF ABOUT 100 TO 200 MICRONS, AND 2. 10 TO 60 PERCENT BY WEIGHT ALUMINA MONOHYDRATES PARTICLES HAVING A SIZE RANGE OF ABOUT 5 TO 65 MICRONS; B. COMBINING SAID MIXTURE WITH WATER TO FORM AN EXTRUDABLE PASTE; C. EXTRUDING SAID PASTE TO FORM COHESIVE EXTRUDATES; AND D. DRYING AND CALCINING THE EXTRUDATE TO FORM HARD MECHANICALLY STRONG PARTICLES.
Claim 2
Independent Claim
133 words
A METHOD FOR PREPARING MECHANICALLY STRONG MACROPOROUS ALUMINA EXTRUDATES HAVING A MERCURY PORE VOLUME OF ABOUT 0.3 TO ABOUT 0.7 CC/G WHEREIN 40 TO 100 PERCENT OF THE PORE VOLUME IS CONTAINED IN PORES HAVING A SIZE ABOVE 3500A IN DIAMETER AND A SURFACE AREA OF ABOUT 200 TO 400 M2/G WHICH COMPRISES; A. PREPARING A MIXTURE WHICH COMPRISES: 1. 40 TO 90 PERCENT BY WEIGHT GAMMA ALUMINA POWDER HAVING A PARTICLE SIZE RANGE OF ABOUT 100 TO 200 MICRONS, AND 2. 10 TO 60 PERCENT BY WEIGHT ALUMINA MONOHYDRATES PARTICLES HAVING A SIZE RANGE OF ABOUT 5 TO 65 MICRONS; B. COMBINING SAID MIXTURE WITH WATER TO FORM AN EXTRUDABLE PASTE; C. EXTRUDING SAID PASTE TO FORM COHESIVE EXTRUDATES; AND D. DRYING AND CALCINING THE EXTRUDATE TO FORM HARD MECHANICALLY STRONG PARTICLES.
Claim 3
Dependent Claim
51 words
10 to 60 percent by weight alumina monohydrate particles having a size range of about 5 to 65 microns; b. combining said mixture with water to form an extrudable paste; c. extruding said paste to form cohesive extrudates; and d. drying and calcining the extrudate to form hard mechanically strong particles.
Claim 4
Dependent Claim
51 words
10 to 60 percent by weight alumina monohydrate particles having a size range of about 5 to 65 microns; b. combining said mixture with water to form an extrudable paste; c. extruding said paste to form cohesive extrudates; and d. drying and calcining the extrudate to form hard mechanically strong particles.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein said gamma alumina is prepared by calcining alumina hydrogel at a temperature of 1,000* to 1, 550*F. for 2 to 16 hours.
Claim 6
Dependent Claim
27 words
The method of claim 1 wherein said alumina monohydrate is prepared by heating alumina hydrogel to a temperature of 150* to 400*F. for 8 to 24 hours.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein said cohesive extrudates are calcined at a temperature of 1,150* to 1,250*F. for 2 to 6 hours.
References Cited (Backward Citations)
US3251783A
Cited
US3669904A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |