Patent US3740308A successfully refreshed from Google Patents.
US3740308A
Expired / Lapsed
US
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Recovery of sodium chloride from spent pulping liquors
Assignee: Electric Reduction Company of Canada Ltd
•
Filing: 1970-12-21
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Granted: 1973-06-19
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Expires: 1990-12-21
Abstract
Abstract A sodium sulfide and sodium chloride-containing smelt formed from waste pulping liquor is fractionated to separate the sodium sulfide from the sodium chloride.
Inventors
- 👤 W Rapson
- 👤 D Reeve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:12
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/12; D21C11/122; Y; Y02; Y02P; Y02P40/00; Y02P40/40; Y10; Y10S; Y10S162/00; Y10S162/08; Y10S423/00; Y10S423/03
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
20 words
The process of claim 1 wherein said smelt is fractionated by contact with water to dissolve preferentially said sodium sulfide.
Claim 2
Dependent Claim
35 words
The process of claim 1 wherein said latter aqueous solution of sodium sulfide is utilized to fractionate said smelt to preferentially dissolve said sodium sulfide from further smelt prior to recycle to said contacting step.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein said smelt is subjected to the action of steam to provide said smelt in a wool-like form prior to fractionation.
Claim 4
Dependent Claim
23 words
The process of claim 1 including introducing to said spent pulping liquor a sodium chloride-containing aqueous medium whereby said smelt contains sodium chloride.
Claim 5
Dependent Claim
15 words
The process of claim 5 wherein said sodium chloride-containing aqueous medium is bleach plant effluent.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |