Patent US3917800A successfully refreshed from Google Patents.
US3917800A
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Method for removing oxides of sulfur from sulfur bearing gas
Assignee: Hanna Mining Co
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Filing: 1973-10-05
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Granted: 1975-11-04
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Expires: 1993-10-05
Abstract
Abstract Gases containing oxygen and sulfur are contacted with a solid sorbent material of ferrous sulfate, iron oxide, or combinations of both, to remove the sulfur from the gas by converting the sorbent to ferric sulfate. The ferric sulfate is decomposed at a low temperature to magnetite and sulfur dioxide in the presence of a reducing agent, and the magnetite is recycled for use as part or all of the solid sorbent in the process.
Inventors
- 👤 Patrick John Mcgauley
- 👤 Abraham A Dor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:57
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/48; C01B17/50; C01B17/60; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/508; C01B17/02; C01B17/04; C01B17/0473; C01G; C01G49/00; C01G49/02; C01G49/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
204 words
A CONTINUOUS PROCESS FOR REMOVING SULFUR OXIDES FROM GASES CONTAINING OXYGEN AND SULFUR OXIDES COMPRISING THE STEPS OF: A. PROVIDING A SOLID SORBENT MATERIAL SELECTED FROM THE CLASS CONSISTING OF FERROUS SULFATE, IRON OXIDE AND MIXTURES THEREOF, B. ADVANCING AT LEAST A PORTION OF SAID ABSORBING SOLIDS TO AN ABSORPTION ZONE, C. CONTACTING THE SULFUR OXIDE-CONTAINING GAS IN THE ABSORPTION ZONE WITH THE SORBENT AT A TEMPERATURE BETWEEN 250* AND 550*C., D. REACTING THE SUFUR OXIDES IN THE GAS WITH THE SOLID SORBENT TO FORM FERRIC SULFATE AND TO PRODUCE A GAS REDUCED IN SULFUR OXIDE CONTENT THAT CAN BE DISCHARGED TO THE ATMOSPHERE, E. DISCHARGING THE GAS REDUCED IN SULFUR OXIDE CONTENT TO THE ATMOSPHERE, F. WITHDRAWING A PORTION OF THE FERRIC SULFATE-BEARING SOLIDS AFTER CONTACT WITH THE SULFUR OXIDE-BEARING GAS. G. CONTACTING SAID FERRIC SULFATE-BEARING SOLIDS IN THE SAID WITHDAWN SOLIDS WITH A HOT REDUCING GAS AT A TEMPERATURE OF FROM ABOUT 300* TO ABOUT 700*C. TO PRODUCE MAGNETIC IN THE DECOMPOSITION PRODUCT AND A PRODUCT GAS THAT CONTAINS SULFUR DIOXIDE, H. RECOVERING THE SULFUR DIOXIDE-BEARING GAS AND THE MAGNETITE-BEARING PRODUCT, AND I. RECYCLING AT LEAST A PORTION OF THE MAGNETITE-BEARING PRODUCT AS THE SOLID FROM IRON OXIDE SORBENT IN STEP (A).
Claim 2
Dependent Claim
204 words
A CONTINUOUS PROCESS FOR REMOVING SULFUR OXIDES FROM GASES CONTAINING OXYGEN AND SULFUR OXIDES COMPRISING THE STEPS OF: A. PROVIDING A SOLID SORBENT MATERIAL SELECTED FROM THE CLASS CONSISTING OF FERROUS SULFATE, IRON OXIDE AND MIXTURES THEREOF, B. ADVANCING AT LEAST A PORTION OF SAID ABSORBING SOLIDS TO AN ABSORPTION ZONE, C. CONTACTING THE SULFUR OXIDE-CONTAINING GAS IN THE ABSORPTION ZONE WITH THE SORBENT AT A TEMPERATURE BETWEEN 250* AND 550*C., D. REACTING THE SUFUR OXIDES IN THE GAS WITH THE SOLID SORBENT TO FORM FERRIC SULFATE AND TO PRODUCE A GAS REDUCED IN SULFUR OXIDE CONTENT THAT CAN BE DISCHARGED TO THE ATMOSPHERE, E. DISCHARGING THE GAS REDUCED IN SULFUR OXIDE CONTENT TO THE ATMOSPHERE, F. WITHDRAWING A PORTION OF THE FERRIC SULFATE-BEARING SOLIDS AFTER CONTACT WITH THE SULFUR OXIDE-BEARING GAS. G. CONTACTING SAID FERRIC SULFATE-BEARING SOLIDS IN THE SAID WITHDAWN SOLIDS WITH A HOT REDUCING GAS AT A TEMPERATURE OF FROM ABOUT 300* TO ABOUT 700*C. TO PRODUCE MAGNETIC IN THE DECOMPOSITION PRODUCT AND A PRODUCT GAS THAT CONTAINS SULFUR DIOXIDE, H. RECOVERING THE SULFUR DIOXIDE-BEARING GAS AND THE MAGNETITE-BEARING PRODUCT, AND I. RECYCLING AT LEAST A PORTION OF THE MAGNETITE-BEARING PRODUCT AS THE SOLID FROM IRON OXIDE SORBENT IN STEP (A).
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein the recovered magnetite-bearing product is oxidized at a temperature below about 450*C. prior to recycling to the absorption zone.
Claim 4
Dependent Claim
28 words
The process of claim 1 wherein the sulfur oxide bearing gas from the decomposition of the iron sulfates is reacted with additional reducing gas to produce elemental sulfur.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein the sulfur dioxide recovered from the decomposition of ferric sulfate is converted to sulfuric acid.
Claim 6
Dependent Claim
22 words
The process of claim 1 wherein the sorbent material supplied to the absorption zone is a mixture of ferrous sulfate and magnetite.
Claim 7
Dependent Claim
28 words
The process of claim 1 and further including the step of feeding said recovered magnetite-bearing product to a sulfur stripper for thermally removing residual sulfur from said magnetite.
Claim 8
Dependent Claim
49 words
The process of claim 1 wherein the product gas from the decomposition of the iron sulfates is treated while hot with sufficient oxygen to oxidize all of the reducing agents in the product gas and to generate a gas containing oxygen and sulfur dioxide suitable for sulfuric acid production.
Claim 9
Dependent Claim
25 words
The process of claim 7 wherein the gas containing sulfur dioxide and oxygen is used as a feed gas for the production of sulfuric acid.
Claim 10
Dependent Claim
87 words
The process of claim 1 wherein the product gas obtained from the decomposition of the iron sulfate in step (g) is: a. treated while hot to remove solid particulate material in the gas, b. reduced in part to convert part of the sulfur dioxide to elemental sulfur and hydrogen sulfide, c. cooled to condense the elemental sulfur in said gas, d. treated to extract the liquid elemental sulfur from the gas, and e. reheated and reacted in the presence of a catalyst to generate additional elemental sulfur.
Claim 11
Dependent Claim
27 words
The process of claim 1 wherein all of the iron oxide in the solid sorbent material of step (a) is generated from magnetite obtained from iron sulfates.
Claim 12
Dependent Claim
18 words
The process of claim 1 wherein the product gas of step (g) is in equilibrium composition with magnetite.
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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |