US4767540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymers containing hydroxamic acid groups for reduction of suspended solids in bayer process streams
Assignee: Wyeth Holdings LLC
•
Filing: 1987-02-11
•
Granted: 1988-08-30
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Expires: 2007-02-11
Abstract
Abstract The suspended solids content of Bayer process streams is reduced by contacting said stream with a polymer which contains hydroxamic acid groups.
Inventors
- 👤 Donald P. Spitzer
- 👤 Wei S. Yen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:17
CPC Classifications
B; B01; B01D; B01D21/00; B01D21/01; C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/06; C01F7/0646; C01F7/0653; C01F7/46; C01F7/47
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
71 words
A process for removing suspended solids from the Bayer alumina process, the improvement comprising contacting and efficiently mixing a Bayer process stream with a water-soluble polymer containing pendant hydroxamic acid or salt groups in an amount effective to flocculate and settle the suspended solids therein, said polymer having a molecular weight ranging from about 1×10 4 to about 3×10 7 and removing flocculated and settled suspended solids from said process stream.
Claim 2
Dependent Claim
71 words
A process for removing suspended solids from the Bayer alumina process, the improvement comprising contacting and efficiently mixing a Bayer process stream with a water-soluble polymer containing pendant hydroxamic acid or salt groups in an amount effective to flocculate and settle the suspended solids therein, said polymer having a molecular weight ranging from about 1×10 4 to about 3×10 7 and removing flocculated and settled suspended solids from said process stream.
Claim 3
Dependent Claim
22 words
A process according to claim 1 wherein said polymer is derived from a polymer containing pendant ester, amide, anhydride or nitrile groups.
Claim 4
Dependent Claim
15 words
A process according to claim 2 wherein said polymer is derived from an amide polymer.
Claim 5
Dependent Claim
15 words
A process according to claim 2 wherein said polymer is derived from an acrylamide polymer.
Claim 6
Dependent Claim
15 words
A process according to claim 2 wherein said polymer is derived from an ester polymer.
Claim 7
Dependent Claim
17 words
A process according to claim 2 wherein said polymer is derived from an acrylate or methacrylate polymer.
Claim 8
Dependent Claim
13 words
A process according to claim 1 wherein said process stream is settler feed.
Claim 9
Dependent Claim
13 words
A process according to claim 1 wherein said process stream is settler overflow.
Claim 10
Dependent Claim
13 words
A process according to claim 1 wherein said process stream is blow-off discharge.
Claim 11
Dependent Claim
20 words
A process according to claim 1 wherein said process stream is feed to a mud washer in the washer train.
Claim 12
Dependent Claim
16 words
A process according to claim 1 wherein said polymer is in the form of an emulsion.
Claim 13
Dependent Claim
23 words
A process according to claim 1 wherein the degree of hydroxamation of said polymer ranges from about 1 to about 90 mole percent.
Claim 14
Dependent Claim
23 words
A process according to claim 1 wherein the degree of hydroxamation of said polymer ranges from about 5 to about 75 mole percent.
Claim 15
Dependent Claim
23 words
A process according to claim 1 wherein the degree of hydroxamation of said polymer ranges from about 10 to about 50 mole percent.
Claim 16
Dependent Claim
17 words
A process according to claim 1 wherein said polymer is employed in conjunction with an anionic flocculant.
Claim 17
Dependent Claim
14 words
A process according to claim 15 wherein said anionic flocculant is starch or flour.
Claim 18
Dependent Claim
17 words
A process according to claim 15 wherein said anionic flocculant is the salt of a polyacrylate polymer.
Claim 19
Dependent Claim
15 words
A process according to claim 15 wherein said anionic flocculant is an acrylate salt/acrylamide copolymer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |