Patent US1776918A successfully refreshed from Google Patents.
Patent US4622149A successfully refreshed from Google Patents.
US4622149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Effluent treatment
Assignee: Vale Canada Ltd
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Filing: 1985-04-29
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Granted: 1986-11-11
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Expires: 2005-04-29
Abstract
Abstract A process in which ferric ion in water-soluble form is added to an effluent containing cyanide, arsenic and antimony and having a pH of about 5 to 9 and treating effluent with SO 2 and oxygen in the presence of soluble copper to produce a treated effluent having very low contents of cyanide, arsenic and antimony.
Inventors
- 👤 Eric A. P. Devuyst
- 👤 Bruce R. Conard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:08
CPC Classifications
C; C22; C22B; C22B3/00; C22B3/20; C22B3/44; C22B3/46; C02; C02F; C02F1/00; C02F1/72; C02F1/74; C02F2101/00; C02F2101/10; C02F2101/103; C02F2101/16; C02F2101/18; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903; Y10S210/904; Y10S210/911; Y10S210/912
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
A process for removing arsenic, antimony and cyanide from aqueous effluent containing same comprising adding effective ferric ion in aqueous solution to said aqueous effluent at a pH of about 5 to 9 in an amount of at least about three times the total weight of said arsenic and said antimony to precipitate arsenic and antimony in occlusion association with precipitated ferric hydroxide, reacting cyanide in said effluent solution with sulfur dioxide and oxygen in the presence of soluble copper catalyst at a pH of about 5 to about 11 to remove said cyanide from said effluent and thereafter separating said precipitated ferric hydroxide containing said arsenic and antimony from said aqueous effluent.
Claim 2
Dependent Claim
113 words
A process for removing arsenic, antimony and cyanide from aqueous effluent containing same comprising adding effective ferric ion in aqueous solution to said aqueous effluent at a pH of about 5 to 9 in an amount of at least about three times the total weight of said arsenic and said antimony to precipitate arsenic and antimony in occlusion association with precipitated ferric hydroxide, reacting cyanide in said effluent solution with sulfur dioxide and oxygen in the presence of soluble copper catalyst at a pH of about 5 to about 11 to remove said cyanide from said effluent and thereafter separating said precipitated ferric hydroxide containing said arsenic and antimony from said aqueous effluent.
Claim 3
Dependent Claim
25 words
A process as in claim 1 wherein sulfur dioxide is employed in the form of an alkali or alkaline earth metal sulfite, bisulfite or pyrosulfite.
Claim 4
Dependent Claim
18 words
A process as in claim 1 wherein ferric ion is added as an aqueous solution of ferric sulphate.
Claim 5
Dependent Claim
13 words
A process as in claim 1 carried out continuously in a single stage.
Claim 6
Dependent Claim
52 words
A process as in claim 1 carried out continuously in two stages wherein the reaction volume in stage 1 is maintained at a pH of about 8 to 10 and the reaction volume in state 2 to which ferric ion is added is maintained at a pH of about 5 to 7.
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) | 1989-11-10 | 1990-05-12 | 1990-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-10 | 1994-05-12 | 1994-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-10 | 1998-05-12 | 1998-11-11 | $7700.00 | Window Closed / Lapsed |