US4615873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of cyanide-ferrocyanide effluents
Assignee: Vale Canada Ltd
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Filing: 1985-04-29
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Granted: 1986-10-07
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Expires: 2005-04-29
Abstract
Abstract A process for treatment of cyanide-containing aqueous effluents in which ferrocyanide present is precipitated with a metal other than copper, preferably zinc either prior to or simultaneously with the treatment of the effluent with sulfur dioxide and air in the presence of soluble copper.
Inventors
- 👤 Eric A. P. Devuyst
- 👤 Branka Tandi
- 👤 Bruce R. Conard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:22
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F1/5245; C02F1/72; C02F1/725; C02F2101/00; C02F2101/10; C02F2101/16; C02F2101/18; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903; Y10S210/904
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
70 words
In a process for treating cyanide-containing solution with sulfur dioxide and oxygen in the presence of a soluble copper catalyst to reduce the cyanide content thereof, the improvement comprising precipitating ferrocyanide species in said solution by means of at least one precipitant selected from the group of ions consisting of zinc, nickel, cadmium, cobalt, lead, mercury and silver prior to or simultaneous with said treatment with sulfur dioxide and oxygen.
Claim 2
Dependent Claim
70 words
In a process for treating cyanide-containing solution with sulfur dioxide and oxygen in the presence of a soluble copper catalyst to reduce the cyanide content thereof, the improvement comprising precipitating ferrocyanide species in said solution by means of at least one precipitant selected from the group of ions consisting of zinc, nickel, cadmium, cobalt, lead, mercury and silver prior to or simultaneous with said treatment with sulfur dioxide and oxygen.
Claim 3
Dependent Claim
18 words
A process as in claim 1 wherein ferrocyanide is formed in said solution by addition of ferrous ion.
Claim 4
Dependent Claim
12 words
A process as in claim 1 wherein said precipitant is zinc ion.
Claim 5
Dependent Claim
12 words
A process as in claim 1 wherein said precipitant is nickel ion.
Claim 6
Dependent Claim
12 words
A process as in claim 1 wherein said precipitant is cadmium ion.
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) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |