US3755110A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the recovery of mercury from the brine filter sludge obtained in the electrolysis of alkali metal chlorides by the amalgam process
Assignee: BASF SE
•
Filing: 1971-03-15
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Granted: 1973-08-28
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Expires: 1991-03-15
Abstract
Abstract Process for the recovery of mercury from the brine filter sludge of alkali-chlorine cells. The brine filter sludge is treated with solutions containing active chlorine for the extraction of mercury or its compounds. Insoluble impurities are filtered off, and the resulting mercuric filtrate is passed to the electrolytic cell where the dissolved mercury is reduced to metal at the cathode under the operating conditions of the cell. Metallic mercury may also be recovered from the filtrate with the aid of sodium amalgam.
Inventors
- 👤 E Wygasch
- 👤 G Weiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:12
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/36; C01; C01G; C01G13/00; C22; C22B; C22B43/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
27 words
A process as in claim 1, wherein the treatment of the brine filter sludge is carried out using aqueous alkali metal hypochlorite, chlorous brine or chlorine water.
Claim 2
Dependent Claim
23 words
A process as set forth in claim 1 wherein the mercuric solution is added to the pure brine fed to the electrolytic cells.
Claim 3
Dependent Claim
85 words
A process for the recovery of mercury from the brine filter sludge obtained from a plant for the electrolysis of alkali metal chloride by the amalgam process which comprises: dissolving the mercury contained in the brine filter sludge in a water-insoluble form, treating the brine filter sludge with a solution containing active chlorine, filtering off the undissolved portion of the brine filter sludge, washing, combining the filtrate and washings, and precipitating the mercury from the resulting mercuric solution by treatment with excess alkali metal amalgam.
Claim 4
Dependent Claim
39 words
A process as set forth in claim 4 wherein the amalgam remaining after the treatment of the mercuric solution is converted to aqueous alkali metal hydroxide, hydrogen and mercury, and the latter is fed to an alkali-chlorine electrolytic cell.
Claim 5
Dependent Claim
34 words
A process as set forth claim 5, wherein the mercury, before it is fed to an alkali chlorine electrolytic cell, is freed from impurities by washing with a dilute acid in a washing tower.
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) | 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 |