US3713786A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Evaporative sulfuric acid recovery from sulfuric acids containing sulfates
Assignee: Manufacturers Hanover Trust Co
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Filing: 1971-12-06
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Granted: 1973-01-30
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Expires: 1991-12-06
Abstract
Abstract SULFURIC ACID IN CONCENTRATED FORM IS RECOVERED FROM DILUTE, WASTE SULFURIC ACID LIQUORS CONTAINING METAL SULFATES, SUCH AS THOSE RESULTING FROM THE LEACHING OF MINERAL VALUES FROM ORES AND THE LIKE OF FROM THE CLEANING METALS SUCH AS IRON AND STEEL. SEPARATION OF THE SULFATE SALTS IN SUBSTANTIALLY DRY FORM IS EFFECTED BY TOTAL EVAPORATION OF THE WATER AND OF THE SULFURIC ACID; CONDENSATION OF THESE VAPORS IS CONTROLLED SO THAT THE RESULTING ACID IS OF INCREASED CONCENTRATION.
Inventors
- 👤 C Umstead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:42
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/36; Y; Y10; Y10S; Y10S159/00; Y10S159/19; Y10S423/00; Y10S423/01; Y10S423/02
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |