US4115260A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective removal of iron cyanide anions from fluids containing thiocyanates
Assignee: Rohm and Haas Co
•
Filing: 1977-04-07
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Granted: 1978-09-19
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Expires: 1997-04-07
Abstract
Abstract Certain strongly basic, acrylic-based anion exchange resins are employed to selectively remove ferrocyanide and ferricyanide anions from aqueous fluids containing thiocyanate anions. A portion of the resin regeneration fluid may be reclaimed for re-use.
Inventors
- 👤 Noyes L. Avery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:00
CPC Classifications
B; B01; B01J; B01J41/00; B01J41/04; B01J41/05
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
A process for separating iron cyanide complex anions from an aqueous fluid comprising thiocyanate anions and anions of at least one iron cyanide complex selected from the group consisting of ferrocyanide and ferricyanide, said iron cyanide complex anions being present at a concentration of at least about 100 parts per billion parts of said fluid, and said thiocyanate anions being present at a concentration of at least five weight percent of the iron cyanide complex anion concentration, said process comprising: (a) contacting said fluid with an acrylic, strongly basic anion exchange resin having the ability to adsorb the iron cyanide complex anions preferentially over the thiocyanate anions, and (b) separating said fluid from said resin.
Claim 2
Dependent Claim
115 words
A process for separating iron cyanide complex anions from an aqueous fluid comprising thiocyanate anions and anions of at least one iron cyanide complex selected from the group consisting of ferrocyanide and ferricyanide, said iron cyanide complex anions being present at a concentration of at least about 100 parts per billion parts of said fluid, and said thiocyanate anions being present at a concentration of at least five weight percent of the iron cyanide complex anion concentration, said process comprising: (a) contacting said fluid with an acrylic, strongly basic anion exchange resin having the ability to adsorb the iron cyanide complex anions preferentially over the thiocyanate anions, and (b) separating said fluid from said resin.
Claim 3
Dependent Claim
23 words
The process according to claim 1 wherein the acrylic based, strongly basic anion exchange resin is the quaternary ammonium salt of crosslinked N-(dimethylaminopropyl)acrylamide.
Claim 4
Dependent Claim
28 words
The process according to claim 2 wherein the polymer is crosslinked with from about 2 to about 15 weight percent of at least one polyethylenically unsaturated crosslinking agent.
Claim 5
Dependent Claim
29 words
The process according to claim 1 wherein the exhausted resin is regenerated by contacting it with an aqueous solution of sodium chloride, and separating said solution from the resin.
Claim 6
Dependent Claim
24 words
The process according to claim 4 wherein the concentration of the sodium chloride solution is between about 1 and about 25 percent by weight.
Claim 7
Dependent Claim
32 words
The process according to claim 1 wherein at least a portion of sodium chloride solution which has been used to regenerate said exhausted resin is re-used without further treatment for resin regeneration.
Claim 8
Dependent Claim
17 words
The process according to claim 1 wherein said aqueous fluid comprises anions of thiocyanate, ferrocyanide and ferricyanide.
Claim 9
Dependent Claim
31 words
The process according to claim 1 wherein said iron cyanide complex anions are present at a concentration from about 50 to about 1000 parts per million parts of said aqueous fluid.
Claim 10
Dependent Claim
17 words
The process according to claim 8 wherein the iron cyanide complex anions are present as ferricyanide anions.
Claim 11
Dependent Claim
17 words
The process according to claim 8 wherein said iron cyanide complex anions are present as ferrocyanide anions.
References Cited (Backward Citations)
US3869383A
Cited
US3931004A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |