US3607069A
Expired / Lapsed
US
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Process for recovering sulfur and metal values from sulfur-bearing minerals
Assignee: Honeywell International Inc
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Filing: 1969-12-09
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Granted: 1971-09-21
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Expires: 1989-12-09
Abstract
Abstract A process for recovering sulfur values and concentrating other metal values from pyrrhotite (FeS) by complexing ferrous sulfide in aqueous medium with an insoluble alkylamino polycarboxylic acid chelating agent to form a water-soluble ferrous chelate, hydrogen sulfide and a concentrate of insoluble sulfides of nonferrous metals. The hydrogen sulfide is reacted Claus sulfur dioxide under conventional Clause reaction conditions to yield sulfur. The ferrous chelate, in solution, is treated with an oxygen-free sulfur dioxide whereby the water-insoluble chelating agent is regenerated for recycle. The solution of ferrous bisulfite which forms is processed to yield additional quantities of sulfur dioxide from which sulfur is recovered.
Inventors
- 👤 Charies Patrick Bruen
- 👤 Donald Hoyt Kelly
- 👤 Christian Albert Wamser
- 👤 Bhaskar Bandyopadhyan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:34
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/05; C01B17/16; C01B17/165; C01G; C01G49/00; C01G49/0009; C01G49/02; C01G49/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
26 words
The process of claim 1 wherein said reaction is effected at a temperature of about 20* C. to the boiling point of the aqueous reaction mixture.
Claim 2
Dependent Claim
20 words
The process of claim 1 wherein the chelating agent contains about up to 4 carbon atoms in the alkyl moiety.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the chelating agent contains about up to 4 carbon atoms in the polycarboxylic acid moiety.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the chelating agent is ethyenediaminetetraacetic acid.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the chelating agent is nitrilotriacetic acid.
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein the hydrogen sulfide product is reacted with sulfur dioxide under conditions sufficient to effect production of elemental sulfur.
Claim 7
Independent Claim
99 words
A method of processing a ferrous sulfide ore which comprises the steps of: a. reacting said ferrous sulfide in aqueous medium with an amount of a water-insoluble alkylamino polycarboxylic acid chelating agent sufficient to effect formation of a water soluble ferrous chelate and byproduct hydrogen sulfide; b. reacting said ferrous chelate solution with a substantially oxygen-free, sulfur dioxide containing medium at a pH of about 1 to 2 and in an amount sufficient to regenerate said water-insoluble alkylamino polycarboxylic chelating agent and form an aqueous solution of ferrous bisulfite; and c. separating said chelating agent from the bisulfite solution.
Claim 8
Dependent Claim
50 words
The process of claim 8 wherein the aqueous solution of ferrous bisulfite from step (c) is heated to a temperature sufficient to produce sulfur dioxide and ferrous sulfite and the ferrous sulfite is heated at a temperature sufficient to desulfurize said ferrous sulfite to produce ferrous oxide and sulfur dioxide.
Claim 9
Dependent Claim
24 words
The process of claim 9 wherein the sulfur dioxide formed is reacted with hydrogen sulfide under conditions sufficient to effect production of elemental sulfur.
Claim 10
Dependent Claim
23 words
The process of claim 9 wherein the sulFur dioxide formed is used to regenerate the alkylamino polycarboxylic chelating agent from the ferrous complex.
Claim 11
Dependent Claim
27 words
The process of claim 8 wherein the regenerated insoluble alkylamino polycarboxylic chelating agent separated in step (c) is recycled to step (a) for reaction with ferrous sulfide.
Claim 12
Dependent Claim
76 words
A process for recovering a water-insoluble alkylamino polycarboxylic acid from an aqueous solution of the soluble ferrous chelate of said acid which comprises reacting said ferrous chelate solution with a substantially oxygen-free sulfur dioxide at a pH of about 1 to 2 and in an amount of said sulfur dioxide sufficient to effect conversion of the ferrous chelate to the insoluble free acid and ferrous bisulfite in solution and recovering said insoluble acid from said solution.
Claim 13
Dependent Claim
30 words
A process as in claim 13 wherein the ferrous bisulfite solution is heated to release sulfur dioxide and precipitate ferrous sulfite and collecting the sulfur dioxide and ferrous sulfite therefrom.
Claim 14
Dependent Claim
43 words
A process as in claim 14 wherein further recovery of water-insoluble chelating agent from the resulting solution after removal of the ferrous sulfite, is attained by repeating the cycle of treating said solution with sulfur dioxide and collecting the precipitated chelating agent therefrom.
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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |