Patent US4306901A successfully refreshed from Google Patents.
US4306901A
Expired / Lapsed
US
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Process for forming steel product from iron while avoiding the liquid state
Assignee: Massachusetts Institute of Technology
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Filing: 1980-05-27
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Granted: 1981-12-22
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Expires: 2000-05-27
Abstract
Abstract Steel is made from iron ore by comminuting the ore and recovering a particle fraction which has a size less than 50 microns. The iron rich particles then are reduced to form iron or magnetite and are beneficiated by magnetic separation. The magnetite particles are further reduced to form small size iron particles. The iron powders produced by these processes are then processed by powder metallurgical techniques.
Inventors
- 👤 Julian Szekely
- 👤 Gregory J. Yurek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:24
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0235; C21; C21B; C21B13/00; C21B13/14; C21B13/146; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
115 words
The process for converting iron ore containing less than about 6 weight percent gangue to a steel product without proceeding through the liquid state which comprises pulverizing said iron ore, separating said pulverized iron ore to obtain a particle stream wherein at least about 70 weight percent of the particles have a size less than 50 micron, reducing said iron ore particles to magnetite in a first reducing step, separating the products from the first reducing step by magnetic separation to form a magnetite-rich stream and reducing said magnetite-rich stream to a product containing at least about 99.8 weight percent iron in a second reducing step and alloying said product to form a steel product.
Claim 2
Dependent Claim
115 words
The process for converting iron ore containing less than about 6 weight percent gangue to a steel product without proceeding through the liquid state which comprises pulverizing said iron ore, separating said pulverized iron ore to obtain a particle stream wherein at least about 70 weight percent of the particles have a size less than 50 micron, reducing said iron ore particles to magnetite in a first reducing step, separating the products from the first reducing step by magnetic separation to form a magnetite-rich stream and reducing said magnetite-rich stream to a product containing at least about 99.8 weight percent iron in a second reducing step and alloying said product to form a steel product.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein said iron ore contains less than about 5 weight percent gangue.
Claim 4
Dependent Claim
27 words
The process of claim 1 wherein said pulverized iron ore particle stream comprises at least about 70 weight percent particles having a size less than 30 microns.
Claim 5
Dependent Claim
15 words
The process of claim 1 wherein said pulverized iron ore is separated by froth flotation.
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) | 1984-12-21 | 1985-06-22 | 1985-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-21 | 1989-06-22 | 1989-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-21 | 1993-06-22 | 1993-12-22 | $7700.00 | Window Closed / Lapsed |