Patent US2790707A successfully refreshed from Google Patents.
US2790707A
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Method for removing chlorates and chlorides from concentrated electrolytic sodium hydroxide
Assignee: Dow Chemical Co
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Filing: 1955-10-03
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Granted: 1957-04-30
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Expires: 1975-10-03
Abstract
No abstract record available.
Inventors
- 👤 Arthur K Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:56
CPC Classifications
C; C01; C01D; C01D1/00; C01D1/04; C01D1/28; C01D1/32
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
128 words
THE PROCESS WHICH COMPRISES DISSOLVING IN AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE OF FROM 40 TO 55 PERCENT CONCENTRATION, AND CONTAINING SODIUM CHLORATE AND SODIUM CHLORIDE AS IMPURITIES, AN AMOUNT OF FERROUS SULFATE WHICH IS FROM 8.55 TO 9.0 TIMES THE WEIGHT OF SODIUM CHLORATE IN THE SOLUTION, MAINTAINING THE RESULTING MIXTURE AT A TEMPERATURE OF AT LEAST 20* C. AT WHICH THE ALKALI SOLUTION IS LIQUID, BUT NOT SIGNIFICANTLY ABOVE 80* C., UNTIL THE REDUCTION OF CHLORATE TO CHLORIDE IS ESSENTIALLY COMPLETE AND FILTERING TO REMOVE INSOLUBLE COMPLEXES CONTAINING SODIUM CHLORIDE, THEREBY TO MAKE THE SOLUTION ESSENTIALLY FREE FROM CHLORATE AND TO DECREASE THE AMOUNT OF SODIUM CHLORIDE THEREIN BY AN AMOUNT NEAR 0.57 PART BY WEIGHT FOR EACH PART OF FERROUS SULFATE USED IN THE PROCESS.
Claim 2
Dependent Claim
128 words
THE PROCESS WHICH COMPRISES DISSOLVING IN AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE OF FROM 40 TO 55 PERCENT CONCENTRATION, AND CONTAINING SODIUM CHLORATE AND SODIUM CHLORIDE AS IMPURITIES, AN AMOUNT OF FERROUS SULFATE WHICH IS FROM 8.55 TO 9.0 TIMES THE WEIGHT OF SODIUM CHLORATE IN THE SOLUTION, MAINTAINING THE RESULTING MIXTURE AT A TEMPERATURE OF AT LEAST 20* C. AT WHICH THE ALKALI SOLUTION IS LIQUID, BUT NOT SIGNIFICANTLY ABOVE 80* C., UNTIL THE REDUCTION OF CHLORATE TO CHLORIDE IS ESSENTIALLY COMPLETE AND FILTERING TO REMOVE INSOLUBLE COMPLEXES CONTAINING SODIUM CHLORIDE, THEREBY TO MAKE THE SOLUTION ESSENTIALLY FREE FROM CHLORATE AND TO DECREASE THE AMOUNT OF SODIUM CHLORIDE THEREIN BY AN AMOUNT NEAR 0.57 PART BY WEIGHT FOR EACH PART OF FERROUS SULFATE USED IN THE PROCESS.
References Cited (Backward Citations)
US2258545A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-04-29 | 1960-10-29 | 1961-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-29 | 1964-10-29 | 1965-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-29 | 1968-10-29 | 1969-04-30 | $7700.00 | Window Closed / Lapsed |