Patent US3897331A successfully refreshed from Google Patents.
US3897331A
Expired / Lapsed
US
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Mercury recovery
Assignee: Honeywell International Inc
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Filing: 1974-10-10
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Granted: 1975-07-29
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Expires: 1994-10-10
Abstract
Abstract In the method for recovering mercury from carbonaceous filter aid used in filtration of mercury cell alkali metal hydroxide solution to remove mercury therefrom, the steps which comprise: slurrying the filter aid in a liquid medium, allowing the slurried filter aid to settle to form a mercury-rich filter aid slurry stratum and a supernatant mercury-lean filter aid slurry stratum, and separately recovering the mercury-rich stratum.
Inventors
- 👤 Bruce T Smith
- 👤 Roger S Pacheco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:40
CPC Classifications
B; B03; B03B; B03B5/00; B03B5/28; B01; B01D; B01D41/00; B01D41/02; C; C22; C22B; C22B43/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
69 words
IN THE METHOD FOR RECOVERING MECURY FROM CARBONACEOUS FILTER AID USED IN FILTRATION OF MERCURY CELL ALKALI METAL HYDRO XIDE SOLUTION TO REMOVE MERCURY THEREFROM, THE STEPS WHICH COMPRISE: A. SLURRYING THE FILTER AID IN A LIQUID MEDIUM, B. ALLOWING THE SLURRIED FILTER AID TO SETTLE TO FORM A MERCURYRICH FILTER AID SLURRY STRATUM AND A SUPERNATANT MERCURYLEAN FILTER AID SLURRY STRATUM, AND C. SEPARATELY RECOVERING THE MERCURY-RICH STRATUM.
Claim 2
Dependent Claim
69 words
IN THE METHOD FOR RECOVERING MECURY FROM CARBONACEOUS FILTER AID USED IN FILTRATION OF MERCURY CELL ALKALI METAL HYDRO XIDE SOLUTION TO REMOVE MERCURY THEREFROM, THE STEPS WHICH COMPRISE: A. SLURRYING THE FILTER AID IN A LIQUID MEDIUM, B. ALLOWING THE SLURRIED FILTER AID TO SETTLE TO FORM A MERCURYRICH FILTER AID SLURRY STRATUM AND A SUPERNATANT MERCURYLEAN FILTER AID SLURRY STRATUM, AND C. SEPARATELY RECOVERING THE MERCURY-RICH STRATUM.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein the filter aid is slurried in an aqueous medium.
Claim 4
Dependent Claim
30 words
The method of claim 2 wherein the filter aid is slurried in an aqueous medium to obtain a filter aid slurry containing about 5 to 100 g./liter of filter aid.
Claim 5
Dependent Claim
30 words
The method of claim 2 wherein the filter aid is slurried in an aqueous medium to obtain a filter aid slurry containing about 10 to 50 g./liter of filter aid.
Claim 6
Dependent Claim
28 words
The method of claim 2 wherein the filter aid is slurried in water to obtain a filter aid slurry containing about 10 to 50 g./liter of filter aid.
Claim 7
Dependent Claim
49 words
The method of claim 1 wherein the Step of slurrying the filter aid in a liquid medium comprises backwashing the filter used in filtration of the mercury cell alkali metal hydroxide solution with water to obtain a filter aid slurry containing about 5 to 100 g./liter of filter aid.
Claim 8
Dependent Claim
49 words
The method of claim 1 wherein the step of slurrying the filter aid in a liquid medium comprises backwashing the filter used in filtration of the mercury cell alkali metal hydroxide solution with water to obtain a filter aid slurry containing about 10 to 50 g./liter of filter aid.
Claim 9
Dependent Claim
22 words
The method of claim 7 wherein additionally the separately recovered mercury-rich stratum is subjected to filtration to separate aqueous and solid phases.
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) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |