Patent US2864670A successfully refreshed from Google Patents.
US2864670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovering acid from waste acid liquors
Assignee: NL Industries Inc
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Filing: 1955-04-11
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Granted: 1958-12-16
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Expires: 1975-04-11
Abstract
No abstract record available.
Inventors
- 👤 Iii Roger Walwark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:48
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/69; C01B17/90; C01B17/901
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A PROCESS FOR TREATING WASTE SULFURIC ACID LIQUOR CONTAINING SOLUBILIZED TRIVALENT ALUM-FORMING CATIONS AND DISSOLVED IRON AND MAGNESIUM IMPURITIES TO OBTAIN A RESIDUAL ACID SOLUTION AMENABLE TO CONCENTRATION WHICH COMPRISES: INTRODUCING INTO SAID LIQUOR A MONOVALENT ALUM-FORMING CONSTITUENT IN AT LEAST AN AMOUNT TO REACT STOICHIOMETRICALLY WITH SAID ALUM-FORMING CATIONS; COOLING THE TREATED LIQUOR TO A TEMPERATURE BELOW ABOUT -10*C., HOLDING SAID LIQUOR AT SAID TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO CRYSTALLIZE OUT AN ALUM COMPOUND AND SAID IRON AND MAGNESIUM IMPURITIES AS A FILTERABLE CRYSTALLINE MASS; AND SEPARATING THE FILTERABLE CRYSTALLINE MASS FROM THE LIQUOR TO OBTAIN A RESIDUAL ACID SOLUTION EFFECTIVELY FREE OF SAID METALLIC IMPURITIES.
Claim 2
Dependent Claim
110 words
A PROCESS FOR TREATING WASTE SULFURIC ACID LIQUOR CONTAINING SOLUBILIZED TRIVALENT ALUM-FORMING CATIONS AND DISSOLVED IRON AND MAGNESIUM IMPURITIES TO OBTAIN A RESIDUAL ACID SOLUTION AMENABLE TO CONCENTRATION WHICH COMPRISES: INTRODUCING INTO SAID LIQUOR A MONOVALENT ALUM-FORMING CONSTITUENT IN AT LEAST AN AMOUNT TO REACT STOICHIOMETRICALLY WITH SAID ALUM-FORMING CATIONS; COOLING THE TREATED LIQUOR TO A TEMPERATURE BELOW ABOUT -10*C., HOLDING SAID LIQUOR AT SAID TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO CRYSTALLIZE OUT AN ALUM COMPOUND AND SAID IRON AND MAGNESIUM IMPURITIES AS A FILTERABLE CRYSTALLINE MASS; AND SEPARATING THE FILTERABLE CRYSTALLINE MASS FROM THE LIQUOR TO OBTAIN A RESIDUAL ACID SOLUTION EFFECTIVELY FREE OF SAID METALLIC IMPURITIES.
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) | 1961-12-15 | 1962-06-16 | 1962-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-15 | 1966-06-16 | 1966-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-15 | 1970-06-16 | 1970-12-16 | $7700.00 | Window Closed / Lapsed |