US4267058A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precipitating agent for dephosphatizing effluent
Assignee: Bayer AG
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Filing: 1979-09-20
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Granted: 1981-05-12
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Expires: 1999-09-20
Abstract
Abstract A precipitating agent for the dephosphatization of effluent comprising by weight about 5 to 75% of active iron (III) sulphate, about 25 to 95% of active iron (III) oxide and 0 to about 10% of anhydrous magnesium sulphate. Optionally, an alkaline constituent such as the oxide or hydroxide of calcium or magnesium may also be present and dephosphatization is effected at a pH of about 4.5 to about 8.5. Extremely low contents of residual phosphorous can be obtained in the filtrate, a precipitate containing iron and phosphorous settling out cleanly.
Inventors
- 👤 Hans Kyri
- 👤 Jurgen Dobbers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:44
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/906
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
A process for the dephosphatization of effluent, comprising mixing the effluent having a pH of about 4.5 to 8.5 with a precipitating agent consisting essentially of about 5 to 75% by weight of active iron (III) sulphate, about 25 to 95% by weight of active iron (III) oxide and 0 to about 10% by weight of anhydrous magnesium sulphate, the active iron (III) sulphate and active iron (III) oxide having been produced by supplying oxygen while roasting iron (II) sulphate for a time insufficient to remove all the sulphate but sufficient to stop at the desired sulphate content.
Claim 2
Dependent Claim
98 words
A process for the dephosphatization of effluent, comprising mixing the effluent having a pH of about 4.5 to 8.5 with a precipitating agent consisting essentially of about 5 to 75% by weight of active iron (III) sulphate, about 25 to 95% by weight of active iron (III) oxide and 0 to about 10% by weight of anhydrous magnesium sulphate, the active iron (III) sulphate and active iron (III) oxide having been produced by supplying oxygen while roasting iron (II) sulphate for a time insufficient to remove all the sulphate but sufficient to stop at the desired sulphate content.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein the mixing with precipitating agent is carried out at a pH of about 5.5 to 8.
Claim 4
Dependent Claim
30 words
A process according to claim 1, wherein the pH is adjusted by an alkaline constituent selected from the group consisting of calcium oxide, calcium hydroxide, magnesium oxide and magnesium hydroxide.
Claim 5
Dependent Claim
23 words
A process according to claim 3, wherein the mixing with precipitating agent is carried out at a pH of about 7 to 7.5.
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) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |