US4717550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purifying alumina
Assignee: Wyeth Holdings LLC
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Filing: 1986-10-09
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Granted: 1988-01-05
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Expires: 2006-10-09
Abstract
Abstract The iron content of Bayer process streams is reduced by contacting said stream with a tertiary hydroxyl-containing polyamine.
Inventors
- 👤 Donald P. Spitzer
- 👤 David W. Lipp
- 👤 Alan S. Rothenberg
- 👤 Hans P. Panzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:18
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/46; C01F7/47; C22; C22B; C22B3/00; C22B3/20; C22B3/26; C22B3/28; C22B3/282; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
46 words
In a process for separating insoluble red mud from Bayer process streams the improvement which comprises contacting and mixing a Bayer process stream with a tertiary polyamine having a molecular weight of at least about 10,000 in an amount effective to reduce the iron content thereof.
Claim 2
Dependent Claim
46 words
In a process for separating insoluble red mud from Bayer process streams the improvement which comprises contacting and mixing a Bayer process stream with a tertiary polyamine having a molecular weight of at least about 10,000 in an amount effective to reduce the iron content thereof.
Claim 3
Dependent Claim
25 words
A process as defined in claim 1 wherein the amount of tertiary polyamine employed comprises at least about 1.0 mg per liter of process stream.
Claim 4
Dependent Claim
38 words
A process as defined in claim 1 wherein the tertiary polyamine employed is produced from (1) a monoalkylamine or monoalkanol amine and (2) epihalohydrin and (3) up to about 10 mole percent of, an alkylene diamine or ammonia.
Claim 5
Dependent Claim
13 words
A process as defined in claim 3 wherein the monoalkylamine employed is monomethylamine.
Claim 6
Dependent Claim
13 words
A process as defined in claim 3 wherein the monoalkylamine employed is monoethanolamine.
Claim 7
Dependent Claim
24 words
A process as defined in claim 1 wherein the polyamine is added between the digestion step and the filtration step of the Bayer process.
Claim 8
Dependent Claim
16 words
A process as defined in claim 1 wherein the polyamine is added to the settler overflow.
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) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |