Patent US2810699A successfully refreshed from Google Patents.
US2810699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alumina stabilized by hafnia to resist alpha alumina formation
Assignee: Houdry Process Corp
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Filing: 1955-03-29
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Granted: 1957-10-22
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Expires: 1975-03-29
Abstract
No abstract record available.
Inventors
- 👤 Sterling E Voltz
- 👤 Sol W Weiler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:02
CPC Classifications
B; B01; B01J; B01J21/00; B01J21/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
THE METHOD OF PREPARING CONTACT MATERIAL HAVING THE CATALYTIC CHARACTERISTICS OF GAMMA ALUMINA AND SUITABLE AS A CATALYST CARRIER, SAID METHOD CONSISTING OF THE STEPS OF: PREPARING PARTICLES OF GAMMA ALUMINA; IMPREGNATING THE GAMMA ALUMINA PARTICLES WITH A SOLUTION OF HAFNIUM NITRATE PROVIDING A PREDETERMINED PROPORTION OF HAFNIUM IONS TO ALUMINUM IONS; DRYING THE IMPREGNATED PARTICLES; AND CALCINING THE DRIED PARTICLES TO COVERT THE HAFNIUM NITRATE TO HAFNIUM DIOXIDE, THEREBY FORMING PARTICLES CONSISTING PRINCIPALLY OF GAMMA ALUMINA AND CONTAINING FOR EVERY THOUSAND METAL IONS IN SAID CONTAC MATERIAL FROM ABOUT 2 TO ABOUT 26 HAFNIUM IONS OF HALNIUM DIOXIDE COMBINED IN THE GAMMA ALUMINA CRYSTAL LATTICE AS A UNIFORMLY, DILUTELY DISTRIBUTED HAFNIUM DIOXIDE, WHEREBY THE CONTACT MATERIAL RESISTS TRANSFORMATION TO THE ALPHA ALUMINA STATE AT ELEVATED TEMPERATURES.
Claim 2
Independent Claim
127 words
THE METHOD OF PREPARING CONTACT MATERIAL HAVING THE CATALYTIC CHARACTERISTICS OF GAMMA ALUMINA AND SUITABLE AS A CATALYST CARRIER, SAID METHOD CONSISTING OF THE STEPS OF: PREPARING PARTICLES OF GAMMA ALUMINA; IMPREGNATING THE GAMMA ALUMINA PARTICLES WITH A SOLUTION OF HAFNIUM NITRATE PROVIDING A PREDETERMINED PROPORTION OF HAFNIUM IONS TO ALUMINUM IONS; DRYING THE IMPREGNATED PARTICLES; AND CALCINING THE DRIED PARTICLES TO COVERT THE HAFNIUM NITRATE TO HAFNIUM DIOXIDE, THEREBY FORMING PARTICLES CONSISTING PRINCIPALLY OF GAMMA ALUMINA AND CONTAINING FOR EVERY THOUSAND METAL IONS IN SAID CONTAC MATERIAL FROM ABOUT 2 TO ABOUT 26 HAFNIUM IONS OF HALNIUM DIOXIDE COMBINED IN THE GAMMA ALUMINA CRYSTAL LATTICE AS A UNIFORMLY, DILUTELY DISTRIBUTED HAFNIUM DIOXIDE, WHEREBY THE CONTACT MATERIAL RESISTS TRANSFORMATION TO THE ALPHA ALUMINA STATE AT ELEVATED TEMPERATURES.
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) | 1960-10-21 | 1961-04-22 | 1961-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-21 | 1965-04-22 | 1965-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-21 | 1969-04-22 | 1969-10-22 | $7700.00 | Window Closed / Lapsed |