US4137164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for clarifying iron ore slimes
Assignee: Wyeth Holdings LLC
•
Filing: 1977-05-02
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Granted: 1979-01-30
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Expires: 1997-05-02
Abstract
Abstract Use of quaternized Mannich bases of low molecular weight polyacrylamides is highly effective in clarification of iron ore slimes.
Inventors
- 👤 Anthony T. Coscia
- 👤 Michael N. D. O'Connor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:26
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C08; C08F; C08F8/00; C08F8/44
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
156 words
A process for clarifying iron ore slimes containing up to about 100,000 parts per million of suspended inorganic solids with a particle size of up to about 2 microns which comprises mixing with said slimes from about 0.1 to 1,000 parts per million, based on the solids content of said slimes, of a water soluble polymer consisting essentially of a polyacrylamide having a content of at least about 50 mol percent of amide groups chemically-modified to contain dimethylaminomethyl groups, the dimethylaminomethyl groups being further modified by quaternization with an alkylating agent, the chemically-modified polyacrylamide having an intrinsic viscosity in the range of about 0.1 to below about 0.5 deciliters per gram measured in 3M NaCl at 30° C. to form suspendible flocs from a portion of the solids present, maintaining said suspendible flocs in suspension in said water until a substantial portion of the remaining solids are adsorbed thereo; and thereafter settling the resulting flocs formed.
Claim 2
Dependent Claim
156 words
A process for clarifying iron ore slimes containing up to about 100,000 parts per million of suspended inorganic solids with a particle size of up to about 2 microns which comprises mixing with said slimes from about 0.1 to 1,000 parts per million, based on the solids content of said slimes, of a water soluble polymer consisting essentially of a polyacrylamide having a content of at least about 50 mol percent of amide groups chemically-modified to contain dimethylaminomethyl groups, the dimethylaminomethyl groups being further modified by quaternization with an alkylating agent, the chemically-modified polyacrylamide having an intrinsic viscosity in the range of about 0.1 to below about 0.5 deciliters per gram measured in 3M NaCl at 30° C. to form suspendible flocs from a portion of the solids present, maintaining said suspendible flocs in suspension in said water until a substantial portion of the remaining solids are adsorbed thereo; and thereafter settling the resulting flocs formed.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said polyacrylamide contains at least 60-90 mol percent of modified acrylamide groups.
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein the dimethylaminomethyl groups are modified by quaternization with dimethyl sulfate.
Claim 5
Dependent Claim
25 words
The process of claim 1 wherein the intrinsic viscosity of said chemically-modified polyacrylamide is in the range of about 0.3 to below about 0.5 dl./g.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein from 0.5 to 100 ppm of said chemically modified polyacrylamide are mixed with said slimes.
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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) | 1982-01-29 | 1982-07-31 | 1983-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-29 | 1986-07-31 | 1987-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-29 | 1990-07-31 | 1991-01-30 | $7700.00 | Window Closed / Lapsed |