US3790370A
Expired / Lapsed
US
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Removal and recovery of metals from polluted waters
Assignee: Université de Sherbrooke
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Filing: 1971-12-23
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Granted: 1974-02-05
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Expires: 1991-12-23
Abstract
Abstract A process for removing metal ions such as mercury, copper, cadmium, zinc, lead, nickel or silver from polluted waters includes causing the metal polluted water and a sulfur-containing precipitating agent to diffuse through peat whereby a water insoluble sulfide of the metal is formed and is adsorbed on the peat and the metal free water is recovered. The process also relates to recovering the metal either as metal oxide or as metal in the case of silver, copper and mercury by burning the metal sulfide-containing peat.
Inventors
- 👤 J Lalancette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:22
CPC Classifications
C; C02; C02F; C02F9/00; C01; C01G; C01G1/00; C01G1/12; C02F1/00; C02F1/28; C02F1/286; C02F1/288; C02F1/52; C02F1/5236; C02F2101/00; C02F2101/10; C02F2101/20; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912; Y10S210/913; Y10S210/914
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
61 words
A process for removing mercury ions from mercury polluted waters which comprises causing a mercury polluted water to diffuse through peat with a solution of sulfur-containing precipitating agent whereby there is formed an insoluble mercury sulfide which is adsorbed by the peat, the ratio of peat to the precipitating agent being at least 15 to 1, and recovering mercury free water.
Claim 2
Dependent Claim
13 words
The process of claim 2 wherein the sulfur-containing precipitating agent is sodium sulfide.
Claim 3
Dependent Claim
24 words
The process of claim 3 wherein the mercury polluted water is diffused through peat which has been previously impregnated with a sodium sulfide solution.
Claim 4
Dependent Claim
26 words
The process according to claim 2 wherein the mercury polluted water and sodium sulfide solution are combined before permitting the mixture to diffuse through the peat.
Claim 5
Dependent Claim
22 words
The process of claim 2 wherein the sodium sulfide solution diffuses through peat which has been impregnated with the mercury polluted water.
Claim 6
Dependent Claim
42 words
The process according to claim 1 wherein the water insoluble metal sulfide is mercury sulfide and the peat containing the mercury sulfide is partially dried, subjected to oxidation in a furnace and the flue gases obtained are condensed to recover liquid mercury.
Claim 7
Dependent Claim
15 words
The process of claim 7 wherein the oxidation is at a temperature of 400*-700* C.
Claim 8
Dependent Claim
65 words
The process according to claim 1 wherein the water insoluble metal sulfide is selected from the group consisting of copper, cadmium, zinc, lead, nickel and silver sulfides and the peat containing the metal sulfide is partially dried, subjected to oxidation in a furnace and the metal is recovered as a member of the group consisting of (1) the metal as such and (2) metal oxide.
Claim 9
Dependent Claim
15 words
The process of claim 9 wherein the oxidation is at a temperature of 400*-700* C.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |