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US4399037A
Expired / Lapsed
US
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Process for working up waste water containing phosphorus
Assignee: Hoechst AG
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Filing: 1981-10-05
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Granted: 1983-08-16
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Expires: 2001-10-05
Abstract
Abstract The invention relates to a process for working up phosphorus-containing waste water by subjecting it to filtration with the use of a filter aid in a centrifugal filter. To this end, waste water with a temperature of at least 46° C. and a pH-value within the range 0.5 to 4.0 is introduced into the centrifugal filter and fitrate coming from the centrifugal filter is introduced into a calming zone and separated therein within an average period of 10 to 60 minutes into yellow phosphorus and water containing 1 to 30 ppm of phosphorus. Water overflowing from the calming zone is treated with an oxidant and the waste water so freed from phosphorus is reacted with a neutralizing agent.
Inventors
- 👤 Herbert Diskowski
- 👤 Johannes Krause
- 👤 Dietrich Mandelkow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:38
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/38; C02F1/385; C02F1/66; C02F1/72; C02F1/74; C02F2103/00; C02F2103/34; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/906
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
118 words
A process for working up phosphorus-containing waste water obtained in the electrothermal production of phosphorus by subjecting it to filtration with the use of a filter aid in a centrifugal filter, which comprises: introducing the waste water with a temperature of at least 46° C. and a pH-value of at least 0.5 but less than 4.0 into the centrifugal filter; introducing filtrate coming from the centrifugal filter into a calming zone and separating it therein with an average period of 10 to 60 minutes into yellow phosphorus and water containing 1 to 30 ppm of phosphorus; treating water overflowing from the calming zone with an oxidant; and neutralizing the waste water so freed from phosphorus with calcium metasilicate.
Claim 2
Dependent Claim
118 words
A process for working up phosphorus-containing waste water obtained in the electrothermal production of phosphorus by subjecting it to filtration with the use of a filter aid in a centrifugal filter, which comprises: introducing the waste water with a temperature of at least 46° C. and a pH-value of at least 0.5 but less than 4.0 into the centrifugal filter; introducing filtrate coming from the centrifugal filter into a calming zone and separating it therein with an average period of 10 to 60 minutes into yellow phosphorus and water containing 1 to 30 ppm of phosphorus; treating water overflowing from the calming zone with an oxidant; and neutralizing the waste water so freed from phosphorus with calcium metasilicate.
Claim 3
Dependent Claim
24 words
A process as claimed in claim 1, wherein the waste water introduced into the centrifugal filter has a temperature of 50° to 75° C.
Claim 4
Dependent Claim
19 words
A process as claimed in claim 2, wherein the waste water has a temperature of 60° to 70° C.
Claim 5
Dependent Claim
25 words
A process as claimed in claim 1, wherein the waste water introduced into the centrifugal filter has a pH-value within the range 2.0 and 3.5.
Claim 6
Dependent Claim
14 words
A process as claimed in claim 1, wherein air is used as the oxidant.
Claim 7
Dependent Claim
16 words
A process as claimed in claim 1, wherein a bleaching liquor is used as the oxidant.
Claim 8
Dependent Claim
16 words
A process as claimed in claim 1, wherein phosphorus furnace slag is used as calcium metasilicate.
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) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |