Patent US3725530A successfully refreshed from Google Patents.
US3725530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removing mercury vapor from gases
Assignee: Resonac Holdings Corp
•
Filing: 1971-01-18
•
Granted: 1973-04-03
•
Expires: 1991-01-18
Abstract
Abstract Mercury vapor contained in various gases, e.g., byproduct hydrogen gas generated by a mercury electrolytic cell producing caustic soda, is removed by a simple and effective method which comprises washing the mercury vapor contaminated gas with a dilute acid solution containing persulfate ions.
Inventors
- 👤 B Kawase
- 👤 I Kojima
- 👤 K Otani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:39
CPC Classifications
C; C01; C01B; C01B3/00; C01B3/50; C01B3/52; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/64; C01G; C01G13/00; C01G13/02; C01B2203/00; C01B2203/04; C01B2203/0415; C01B2203/0465
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
20 words
The method according to claim 1 wherein the washing is carried out at a normal temperature under a normal pressure.
Claim 2
Dependent Claim
21 words
The method of claim 1 wherein said gas is contacted with said acid solution by countercurrent flow through a packed tower.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein mercury metal is recovered from the acid solution obtained by said washing by adding a reducing agent to said solution.
Claim 4
Dependent Claim
12 words
The method of claim 4 wherein said reducing agent is sulfur dioxide.
Claim 5
Dependent Claim
26 words
The method of claim 5 wherein the sulfur dioxide is introduced into the acid solution at about 60* C. and at a pressure above atmospheric pressure.
Claim 6
Dependent Claim
31 words
The method of claim 4 wherein the acid solution following recovery of mercury metal therefrom has additional persulfate dissolved therein and is recycled for further washing of mercury vapor containing gas.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |