US3755530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for treatment of waste solutions
Assignee: AT&T Inc
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Filing: 1971-11-24
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Granted: 1973-08-28
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Expires: 1991-11-24
Abstract
Abstract SOLIDS ARE REMOVED FROM WASTE SOLUTIONS OF METAL FINSIHING PROCESSES BY INJECTING DROPLETS OF THE SOLUTION INTO A REFRIGERANT TO QUICK-FREEZE THEM, FOLLOWED BY REMOVAL OF ICE BY SUBLIMATION IN A CONTROLLED VACUUM. THE SOLIDS MAY THEN BE INCINERATED TO DECOMPOSE METALLIC SALTS AND IN PARTICULAR TOXIC MATERIALS SUCH AS CYANIDES TO LEAVE A RESIDUE WHICH MAY BE RICH IN PRECIOUS OR COSTLY NONPRECIOUS METALS OR THEIR OXIDES, SUCH AS GOLD, SILVER OR COPPER OXIDE. THESE METALS MAY BE RECYCLED, WHILE THE SUBLIMED WATER MAY BE EITHER CONDENSED AND REUSED OR DISCARDED.
Inventors
- 👤 A Avila
- 👤 R Jaeger
- 👤 T Miller
- 👤 H Sauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:07
CPC Classifications
C; C22; C22B; C22B7/00; C22B7/005; C01; C01B; C01B13/00; C01B13/14; C01C; C01C3/00; C01C3/02; C01C3/0262; C01C3/0283; C01C3/0287; C02; C02F; C02F11/00; C02F11/18; C02F11/20; C09; C09K; C09K5/00; C09K5/20; C22B7/001; C02F2101/00; C02F2101/10; C02F2101/16; C02F2101/18; C02F2101/20; C02F2101/22; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
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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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |