US4332779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phosphoric acid filtration process
Assignee: Wyeth Holdings LLC
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Filing: 1980-11-24
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Granted: 1982-06-01
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Expires: 2000-11-24
Abstract
Abstract An improved process for the filtration of phosphoric acid wherein the prefilt phosphoric acid produced from the "wet process" is conditioned with a flocculant and a dispersant and thereafter filtered to concentrate the acid.
Inventors
- 👤 Michael J. Thibodeau
- 👤 James S. Balcerski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:06
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/22; C01B25/222; C01B25/223
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
78 words
A process for the filtration of phosphoric acid produced by the wet-process comprising initially adding to the prefilt phosphoric acid an effective amount of a cationic flocculant and a dispersant said dispersant being selected from the group consisting of polyacrylates, polysulfonates polyphosphates, and sulfonated polycondensates wherein the ratio of the flocculant to dispersant is from about 0.1:1.0 to 10.0:1.0, respectively, conditioning the prefilt phosphoric acid and thereafter filtering the phosphoric acid to remove impurities and concentrate the acid.
Claim 2
Dependent Claim
78 words
A process for the filtration of phosphoric acid produced by the wet-process comprising initially adding to the prefilt phosphoric acid an effective amount of a cationic flocculant and a dispersant said dispersant being selected from the group consisting of polyacrylates, polysulfonates polyphosphates, and sulfonated polycondensates wherein the ratio of the flocculant to dispersant is from about 0.1:1.0 to 10.0:1.0, respectively, conditioning the prefilt phosphoric acid and thereafter filtering the phosphoric acid to remove impurities and concentrate the acid.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein the cationic flocculant employed is a copolymer containing an ethylenically unsaturated monomer and either an amine or quaternary comonomer.
Claim 4
Dependent Claim
17 words
The process of claim 2 wherein the cationic flocculant is a copolymer of methacrylamidopropyltriammonium chloride and acrylamide.
Claim 5
Dependent Claim
17 words
The process of claim 2 wherein the cationic flocculant is a copolymer of dimethylaminoethylmethylacrylate quaternary and acrylamide.
Claim 6
Dependent Claim
67 words
A process for the filtration of phosphoric acid produced by the wet process comprising initially adding to the prefilt phosphoric acid an effective amount of a cationic flocculant and a polyacrylate dispersant wherein the ratio of the flocculant to the polyacrylate dispersant is from about 0.1:1.0 to 10.0:1.0, respectively, conditioning the prefilt phosphoric acid and thereafter filtering the phosphoric acid to remove impurities and concentrate the acid.
Claim 7
Dependent Claim
67 words
A process for the filtration of phosphoric acid produced by the wet process comprising initially adding to the prefilt phosphoric acid an effective amount of a cationic flocculant and a polyacrylate dispersant wherein the ratio of the flocculant to the polyacrylate dispersant is from about 0.1:1.0 to 10.0:1.0, respectively, conditioning the prefilt phosphoric acid and thereafter filtering the phosphoric acid to remove impurities and concentrate the acid.
Claim 8
Dependent Claim
87 words
A process for the filtration of phosphoric produced by the wet process comprising initially adding to the prefilt phosphoric acid about 5 to 20 parts of a cationic flocculant and a dispersant said dispersant being selected from the group consisting of polyacrylates, polysulfonates polyphosphates, and sulfonated polycondensates per million parts of phosphoric acid wherein the ratio of the flocculant to the dispersant is from about 0.1:1.0 to 10.0:1.0, respectively, conditioning the prefilt phosphoric acid and thereafter filtering the phosphoric acid to remove impurities and concentrate the acid.
Claim 9
Dependent Claim
87 words
A process for the filtration of phosphoric produced by the wet process comprising initially adding to the prefilt phosphoric acid about 5 to 20 parts of a cationic flocculant and a dispersant said dispersant being selected from the group consisting of polyacrylates, polysulfonates polyphosphates, and sulfonated polycondensates per million parts of phosphoric acid wherein the ratio of the flocculant to the dispersant is from about 0.1:1.0 to 10.0:1.0, respectively, conditioning the prefilt phosphoric acid and thereafter filtering the phosphoric acid to remove impurities and concentrate the acid.
Claim 10
Dependent Claim
17 words
The process of claim 5 wherein the flocculant is a copolymer of acrylamide and dimethylamino ethylmethylacrylate quaternary.
Claim 11
Dependent Claim
17 words
The process of claim 5 wherein the flocculant is a copolymer of acrylamide and dimethylamino ethylmethylacrylate quaternary.
Claim 12
Dependent Claim
21 words
The process of claim 1 wherein the ratio of flocculant to dispersant being added is from about 1.0:1.0 to 2.0:1.0, respectively.
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) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |