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US4397683A
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Desulfurization of fluid materials
Assignee: Union Oil Company of California
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Filing: 1980-07-31
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Granted: 1983-08-09
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Expires: 2000-07-31
Abstract
Abstract A method for desulfurizing fluid materials, comprising reacting sulfur to be removed with a rare earth compound, thereby forming rare earth sulfides, oxysulfides or mixtures thereof. The reaction is conducted under conditions of low oxygen potential. Rare earth sulfides and oxysulfides can be reacted with oxygen to restore a capacity for desulfurization.
Inventors
- 👤 D. Alan R. Kay
- 👤 William G. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:26
CPC Classifications
C; C21; C21C; C21C1/00; C21C1/02; C21C7/00; C21C7/04; C21C7/064
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
51 words
A method for decreasing the concentration of reactive sulfur in a fluid material, comprising reacting at least a portion of the sulfur with a nonmetallic rare earth compound, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
Claim 2
Independent Claim
51 words
A method for decreasing the concentration of reactive sulfur in a fluid material, comprising reacting at least a portion of the sulfur with a nonmetallic rare earth compound, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
Claim 3
Dependent Claim
31 words
The method as described in claim 1 wherein the rare earth compound is selected from the group consisting of rare earth oxides, rare earth fluorocarbonates, rare earth oxyfluorides, and mixtures thereof.
Claim 4
Dependent Claim
15 words
The method as described in claim 2 wherein rare earth fluorocarbonates comprise concentrates of bastnasite.
Claim 5
Dependent Claim
16 words
The method as described in claim 2 wherein rare earth oxyfluorides comprise roasted concentrates of bastnasite.
Claim 6
Dependent Claim
18 words
The method as described in claim 2 wherein rare earth oxyfluorides comprise acid leached, roasted concentrates of bastnasite.
Claim 7
Dependent Claim
19 words
The method as described in claim 1 wherein a low oxygen potential is obtained by introducing an inert gas.
Claim 8
Dependent Claim
19 words
The method as described in claim 1 wherein a low oxygen potential is obtained by applying a partial vacuum.
Claim 9
Dependent Claim
19 words
The method as described in claim 1 wherein a low oxygen potential is obtained by introducing a deoxidizing agent.
Claim 10
Dependent Claim
13 words
The method as described in claim 8 wherein a deoxidizing agent is carbon.
Claim 11
Dependent Claim
26 words
The method as described in claim 9 wherein carbon monoxide, produced from the oxidation of carbon, is maintained at a partial pressure below about 0.1 atmosphere.
Claim 12
Dependent Claim
14 words
The method as described in claim 1 wherein the fluid material is a liquid.
Claim 13
Dependent Claim
13 words
The method as described in claim 11 wherein the liquid comprises molten metal.
Claim 14
Dependent Claim
12 words
The method as described in claim 12 wherein the metal is iron.
Claim 15
Dependent Claim
14 words
The method as described in claim 1 wherein the fluid material is a gas.
Claim 16
Independent Claim
41 words
A method for desulfurizing molten iron, comprising reacting sulfur to be removed with a nonmetallic rare earth compound, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
Claim 17
Independent Claim
41 words
A method for desulfurizing molten iron, comprising reacting sulfur to be removed with a nonmetallic rare earth compound, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
Claim 18
Dependent Claim
31 words
The method as described in claim 15 wherein the rare earth compound is selected from the group consisting of rare earth oxides, rare earth fluorocarbonates, rare earth oxyfluorides, and mixtures thereof.
Claim 19
Dependent Claim
38 words
The method as described in claim 15 wherein the molten iron contains carbon, and wherein the oxygen potential is maintained at a low level by reducing the partial pressure of carbon monoxide which forms by oxidation of carbon.
Claim 20
Dependent Claim
20 words
The method as described in claim 17 wherein the partial pressure of carbon monoxide is maintained below about 0.1 atmosphere.
Claim 21
Dependent Claim
23 words
The method as described in claim 15 wherein the rare earth sulfides and oxysulfides are reacted with oxygen to restore capacity for desulfurization.
Claim 22
Independent Claim
40 words
A method for desulfurizing gases, comprising reacting sulfur to be removed with a nonmetallic rare earth compound, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
Claim 23
Independent Claim
40 words
A method for desulfurizing gases, comprising reacting sulfur to be removed with a nonmetallic rare earth compound, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
Claim 24
Dependent Claim
31 words
The method as described in claim 19 wherein the rare earth compound is selected from the group consisting of rare earth oxides, rare earth fluorocarbonates, rare earth oxyfluorides, and mixtures thereof.
Claim 25
Dependent Claim
23 words
The method as described in claim 20 wherein the rare earth sulfides and oxysulfides are reacted with oxygen to restore capacity for desulfurization.
Claim 26
Dependent Claim
20 words
The method as described in claim 20 wherein the sulfur to be removed is in the form of hydrogen sulfide.
Claim 27
Independent Claim
47 words
A method for decreasing the hydrogen sulfide content of gases, comprising reacting at least a portion of the hydrogen sulfide with calcined bastnasite concentrate, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
Claim 28
Independent Claim
47 words
A method for decreasing the hydrogen sulfide content of gases, comprising reacting at least a portion of the hydrogen sulfide with calcined bastnasite concentrate, at a sufficiently low oxygen potential to form one of the group consisting of rare earth sulfides, rare earth oxysulfides, and mixtures thereof.
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) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |