US4042375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Roasting process for the direct reduction of ores
Assignee: Orica Ltd
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Filing: 1975-10-06
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Granted: 1977-08-16
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Expires: 1995-10-06
Abstract
Abstract A roasting process for the direct reduction of ores containing iron oxides which process comprises the following steps in sequence; 1. forming core pellets comprising finely ground ore; 2. coating the core pellets with a coke precursor so that the ratio of skin thickness of coke precursor to the diameter of the core pellets is in the range from 0.1:20 to 1:2. 3. heating the coated pellets in a substantially non-oxidizing atmosphere to a temperature below 1200° C but high enough to cause the coke precursor to form a coke skin around the core pellet; Wherein the coke precursor comprises from 5 to 25% w/w of a halide salt.
Inventors
- 👤 Anwyn Margaret Martin
- 👤 Donald Ferguson Stewart
- 👤 Andrew Baikie Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:05
CPC Classifications
C; C22; C22B; C22B1/00; C22B1/02; C22B1/08; C21; C21B; C21B13/00; C21B13/0046; C21B13/10; C21B13/105; C22B1/14; C22B1/24; C22B1/2413; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
79 words
In a process for the direct reduction of ores containing iron oxides by the reductive roasting of pellets containing the ore, the improvement whereby the pellets retain their pellet form during reduction and have a reduced tendency to coalesce, said improvement comprising using for said reduction pellets which have been prepared by the following steps in sequence; 1. forming core pellets consisting essentially of finely ground ore or a mixture of finely ground ore and solid carbonaceous material; 2.
Claim 2
Dependent Claim
79 words
In a process for the direct reduction of ores containing iron oxides by the reductive roasting of pellets containing the ore, the improvement whereby the pellets retain their pellet form during reduction and have a reduced tendency to coalesce, said improvement comprising using for said reduction pellets which have been prepared by the following steps in sequence; 1. forming core pellets consisting essentially of finely ground ore or a mixture of finely ground ore and solid carbonaceous material; 2.
Claim 3
Dependent Claim
94 words
coating the core pellets with a coke precursor so that the ratio of skin thickness of coke precursors to the diameter of the coke pellets is in the range from 1:20 to 1:2; 3. heating the coated pellets in a substantially non oxidizing atmosphere to a temperature below 1200° C but high enough to cause the coke precursor to form a coke skin around the coke pellet; the coke precursor comprising from 5 to 25% of a halide salt chosen from the group consisting of chlorides, alkaline earth metal chlorides and fluorides and ammonium
Claim 4
Dependent Claim
94 words
coating the core pellets with a coke precursor so that the ratio of skin thickness of coke precursors to the diameter of the coke pellets is in the range from 1:20 to 1:2; 3. heating the coated pellets in a substantially non oxidizing atmosphere to a temperature below 1200° C but high enough to cause the coke precursor to form a coke skin around the coke pellet; the coke precursor comprising from 5 to 25% of a halide salt chosen from the group consisting of chlorides, alkaline earth metal chlorides and fluorides and ammonium
Claim 5
Dependent Claim
15 words
chloride. 2. A process according to claim 1 wherein the halide salt is sodium chloride.
Claim 6
Dependent Claim
19 words
A process according to claim 1 wherein the coke precursor comprises from 10 to 20% of the halide salt.
Claim 7
Dependent Claim
27 words
A process according to claim 1 inclusive wherein the ratio of thickness of coke precursor to diameter of core in step 2 is from 0.8:10 to 2.3:10.
Claim 8
Dependent Claim
31 words
A process according to claim 1 inclusive wherein the ore containing iron oxide is chosen from the group consisting of magnetite, haematite, goethite, bauxite, ilmenite, limonite, titano-magnetite, laterite, chromite and serpentinite.
Claim 9
Dependent Claim
14 words
A process according to claim 1 inclusive wherein the core comprises solid carbonaceous material.
References Cited (Backward Citations)
US2869850A
Cited
US3382063A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |