US4154608A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of high purity iron powder
Assignee: Honeywell UOP LLC
•
Filing: 1978-07-19
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Granted: 1979-05-15
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Expires: 1998-07-19
Abstract
Abstract High purity iron powder may be obtained by treating an iron bearing source which contains impurities such as silica along with minor amounts of aluminum, calcium and magnesium to a series of steps which include grinding the iron bearing source followed by subjecting the ground source to a caustic leach at an elevated temperature and pressure. Thereafter the soluble impurities may be separated from the residue, the latter then being reduced by treatment with hydrogen at an elevated temperature and pressure to convert the iron to the metallic form.
Inventors
- 👤 Curtis D. Carey
- 👤 Martin C. Kuhn
- 👤 Margaret K. Witte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:38
CPC Classifications
C; C21; C21B; C21B15/00; B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/20; B22F9/22; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
76 words
A process for the recovery of metallic iron from an iron bearing source which comprises the steps of: (a) grinding said iron bearing source; (b) subjecting the ground iron bearing source to a caustic leach at an elevated temperature and pressure; (c) separating the impurities from the caustic leach residue; (d) reducing the iron in said caustic leach residue by treatment with hydrogen at an elevated temperature and pressure; and (e) recovering the resultant metallic iron.
Claim 2
Dependent Claim
76 words
A process for the recovery of metallic iron from an iron bearing source which comprises the steps of: (a) grinding said iron bearing source; (b) subjecting the ground iron bearing source to a caustic leach at an elevated temperature and pressure; (c) separating the impurities from the caustic leach residue; (d) reducing the iron in said caustic leach residue by treatment with hydrogen at an elevated temperature and pressure; and (e) recovering the resultant metallic iron.
Claim 3
Dependent Claim
46 words
The process as set forth in claim 1 in which said caustic leach is effected at a temperature in the range of from about 300° to about 400° F. and a pressure in the range of from about 200 to about 400 pounds per square inch.
Claim 4
Dependent Claim
48 words
The process as set forth in claim 1 in which the reduction of said iron is effected at a temperature in the range of from about 700° to about 1900° F. and a pressure in the range of from about atmospheric to about 500 pounds per square inch.
Claim 5
Dependent Claim
37 words
The process as set forth in claim 1 further characterized in that said iron bearing source is reduced by treatment with hydrogen at an elevated temperature and pressure prior to being ground to the desired particle size.
Claim 6
Dependent Claim
42 words
The process as set forth in claim 4 in which said elevated temperature is in a range of from about 700° to about 1300° F. and a pressure in the range of from about atmospheric to about 500 pounds per square inch.
Claim 7
Dependent Claim
30 words
The process as set forth in claim 4 further characterized in that the reduced iron bearing source is subjected to at least one magnetic separation step to separate impurities therefrom.
Claim 8
Dependent Claim
25 words
The process as set forth in claim 1 further characterized in that the caustic leach residue is treated with an acid to remove impurities therefrom.
Claim 9
Dependent Claim
15 words
The process as set forth in claim 7 in which said acid is hydrochloric acid.
Claim 10
Dependent Claim
38 words
The process as set forth in claim 7 further characterized in that the residue from said acid treatment is reduced by treatment with hydrogen at a temperature in the range of from about 700° to about 1900° F.
Claim 11
Dependent Claim
34 words
The process as set forth in claim 9 further characterized in that the reduced iron is ground to a desired particle size in the range of from about -40 mesh to about +270 mesh.
Claim 12
Dependent Claim
28 words
The process as set forth in claim 10 further characterized in that the ground iron is subjected to at least one magnetic separation step to remove impurities therefrom.
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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) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |