Patent US3725259A successfully refreshed from Google Patents.
US3725259A
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US
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Process for recovery of mineral pollutants from acidic waste streams
Assignee: Aerojet Rocketdyne Inc
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Filing: 1970-12-04
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Granted: 1973-04-03
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Expires: 1990-12-04
Abstract
Abstract THIS PATENT DESCRIBES A METHOD FOR THE REMOVAL OF GROUP IB, IIB, III, IV, V, VI, VII AND VIII METAL SALTS FROM ACIDIC WASTE STREAMS SUCH AS ACID MINE DRAINAGE, PICKLING WASTE, AND ELECTROPLATING WASTE WHEREIN THE WASTE STREAM IS HIGHLY ACIDIC AND CONTAINS THESE METAL SALTS AS POLLUTANTS WHICH COMPRISES: CONTACTING SAID STREAM IN COUNTERCURRENT FASHION WITH A CATION EXCHANGE BED CONTAINING A MODERATELY STRONG OR WEAKLY ACIDIC CATION EXCHANGE RESIN TO DEPOSIT METAL IONS FROM SAID SALTS THEREON, NEUTRALIZING THE ACIDIC EFFLUENT FROM THE CATION EXCHANGE RESIN TO PROVIDE ANEUTRAL EFFLUENT, AND REGENERATING SAID CATION ION EXCHANGE RESIN WITH A SOLUTION OF A CHELATING AGENT.
Inventors
- 👤 Pree D De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:08
CPC Classifications
C; C02; C02F; C02F9/00; B; B01; B01J; B01J49/00; B01J49/50; B01J49/53; C22; C22B; C22B3/00; C22B3/20; C22B3/42; C02F2101/00; C02F2101/10; C02F2101/20; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |