US3615339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing iron powder from hematite ores
Assignee: W J DENNIS STONE
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Filing: 1968-10-17
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Granted: 1971-10-26
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Expires: 1988-10-17
Abstract
Abstract A process for producing iron powder in which a hematite ore concentrate is ground and passed through a high-intensity wet magnetic separator to remove silica and other acid insoluble impurities, after which the purified hematite is reduced in the presence of hydrogen to form iron powder.
Inventors
- 👤 W J Dennis Stone
- 👤 David Stewart Hay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:06
CPC Classifications
C; C21; C21B; C21B15/00; B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/20; C21B13/00; C21B13/006; C21B13/14; C21B13/146; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
25 words
A process according to claim 1 wherein the purified hematite contaiNs less than about 0.2 percent by weight of silica and other acid insoluble impurities.
Claim 2
Dependent Claim
17 words
A process according to claim 1 wherein the reducing agent is a reducing gas containing free hydrogen.
Claim 3
Dependent Claim
14 words
A process according to claim 3 wherein a carbonaceous reducing agent is also used.
Claim 4
Dependent Claim
14 words
A process according to claim 3 wherein the reduction is conducted in two stages.
Claim 5
Dependent Claim
25 words
A process according to claim 3 wherein the reduction is conducted at temperatures within the range of 1,600* F. to the melting point of iron.
Claim 6
Dependent Claim
19 words
A process according to claim 6 wherein the reduction is conducted at a temperature of 2,000* - 2,200* F.
Claim 7
Dependent Claim
38 words
A process according to claim 3 wherein the iron is obtained from the reduction zone in the form of a mass of loosely adhering particles which are separated into discrete particles and densified by means of impact densification.
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) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |