Patent US4324665A successfully refreshed from Google Patents.
US4324665A
Expired / Lapsed
US
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Process for recovering bromine from waste liquid
Assignee: Ishihara Sangyo Kaisha Ltd
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Filing: 1980-11-05
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Granted: 1982-04-13
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Expires: 2000-11-05
Abstract
Abstract This is a process for recovering bromine from a waste liquid formed in the production of an aniline derivative by ammonolysis of a nuclear substituted bromobenzene derivative with a halogen atom or a functional group. The waste liquid is first subjected to chlorine treatment in alkaline region to remove most part of ammonia and aniline derivatives, and then it is subjected to chlorine treatment in acidic region to recover bromine. The process does not involve danger of explosion accidents and can be smoothly operated.
Inventors
- 👤 Isao Yokomichi
- 👤 Takeo Yamada
- 👤 Akio Mohri
- 👤 Kiyoshi Ota
- 👤 Minoru Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:46
CPC Classifications
C; C01; C01B; C01B7/00; C01B7/09; C01B7/096; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F1/72; C02F1/76; C02F2101/00; C02F2101/10; C02F2101/12; C02F2209/00; C02F2209/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
166 words
A process for recovering bromine, from a waste liquid formed in the production of an aniline derivative by ammonolysis of a bromobenzene derivative nuclear substituted with at last one halogen atom or functional group, or from a similar liquid, said process being characterized by containing the following steps: (a) adding to said liquid an alkaline material in an amount of not less than 1.1 mole-times the combined ammonia content in said liquid; (b) bringing the resulting liquid into contact with gaseous chlorine until the oxidation-reduction potential of the liquid reaches at least 400 mV; (c) filtering and removing the formed percipitate; (d) adding a mineral acid or an acidic waste liquid containing a mineral acid before or after the above-said step (c) to adjust the pH of the liquid to 3 or less; then, (e) bringing the resulting liquid into contact with gaseous chlorine while allowing the liquid to flow down through a vertically long, gas-liquid contact equipment, and simultaneously introducing steam to distill bromine out.
Claim 2
Dependent Claim
166 words
A process for recovering bromine, from a waste liquid formed in the production of an aniline derivative by ammonolysis of a bromobenzene derivative nuclear substituted with at last one halogen atom or functional group, or from a similar liquid, said process being characterized by containing the following steps: (a) adding to said liquid an alkaline material in an amount of not less than 1.1 mole-times the combined ammonia content in said liquid; (b) bringing the resulting liquid into contact with gaseous chlorine until the oxidation-reduction potential of the liquid reaches at least 400 mV; (c) filtering and removing the formed percipitate; (d) adding a mineral acid or an acidic waste liquid containing a mineral acid before or after the above-said step (c) to adjust the pH of the liquid to 3 or less; then, (e) bringing the resulting liquid into contact with gaseous chlorine while allowing the liquid to flow down through a vertically long, gas-liquid contact equipment, and simultaneously introducing steam to distill bromine out.
Claim 3
Dependent Claim
57 words
A process for recovering bromine from a waste liquid according to claim 1, wherein said process is characterized in that the liquid obtained in the above-said step (a) is subjected to distillation to remove at least part of ammonia and aniline derivatives in the liquid and subsequently is treated as in the above-said steps (b) to (e).
Claim 4
Dependent Claim
47 words
A process for recovering bromine from a waste liquid according to claim 1 or 2, wherein said process is characterized in that in the above-said step (a) an alkaline material is added in an amount of 1.2 to 1.5 mole-times the combined ammonia content in the liquid.
Claim 5
Dependent Claim
46 words
A process for recovering bromine from a waste liquid according to claim 1 or 2, wherein said process is characterized in that in the above-said step (b) gaseous chlorine is introduced until the oxidation-reduction potential of the liquid becomes a voltage of 600 to 700 mV.
Claim 6
Dependent Claim
44 words
A process for recovering bromine from a waste liquid according to claim 3, wherein said process is characterized in that in the above-said step (b) gaseous chlorine is introduced until the oxidation-reduction potential of the liquid reaches a voltage of 600 to 700 mV.
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) | 1985-04-12 | 1985-10-12 | 1986-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-12 | 1989-10-12 | 1990-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-12 | 1993-10-12 | 1994-04-13 | $7700.00 | Window Closed / Lapsed |