US4082539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the preliminary treatment of materials for sintering
Assignee: Nippon Steel Corp
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Filing: 1976-04-01
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Granted: 1978-04-04
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Expires: 1996-04-01
Abstract
Abstract A new method for the preliminary treatment of the raw materials used for sintering of powdery iron ore is provided, in which the hydrophilic binder is dividedly incorporated in a first treatment step and/or a second treatment step. The solid carbon is also dividedly incorporated. The high productivity and quality of the product can thus be maintained and also the NOx conversion rate can be largely decreased.
Inventors
- 👤 Kinichi Sugawara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:55
CPC Classifications
C; C22; C22B; C22B1/00; C22B1/14; C22B1/24; C22B1/242; C22B1/244; C22B1/245
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
156 words
In a method for preliminarily treating sintering materials containing fine powder of a particle size of less than 125μ in the range of 15% to 35% comprising adding in a first treatment step solid carbon to a mix component consisting of powdery or fine powdery iron ore, fluxing materials, dust recovered from steel-making operations and return fines from a sintering operation and then mixing, effecting moisture adjustment, and subjecting said component to a pseudo granule formation operation, and then adding in a second treatment step solid carbon to the material resulting from said first step and thereafter effecting mixing, moisture adjustment and pseudo granule formation operations, the improvement wherein mini-pellets at least 75% of which are of a size of 1 to 7 mm are added in the second step to said first step material in an amount of 3% to 15% by weight of the materials present other than coke, return fines and hearth layer.
Claim 2
Dependent Claim
156 words
In a method for preliminarily treating sintering materials containing fine powder of a particle size of less than 125μ in the range of 15% to 35% comprising adding in a first treatment step solid carbon to a mix component consisting of powdery or fine powdery iron ore, fluxing materials, dust recovered from steel-making operations and return fines from a sintering operation and then mixing, effecting moisture adjustment, and subjecting said component to a pseudo granule formation operation, and then adding in a second treatment step solid carbon to the material resulting from said first step and thereafter effecting mixing, moisture adjustment and pseudo granule formation operations, the improvement wherein mini-pellets at least 75% of which are of a size of 1 to 7 mm are added in the second step to said first step material in an amount of 3% to 15% by weight of the materials present other than coke, return fines and hearth layer.
Claim 3
Dependent Claim
17 words
The method according to claim 1 in which the solid carbon is a coke or coke breeze.
Claim 4
Dependent Claim
20 words
The method according to claim 1 in which the mini-pellet contains 1 to 5% by weight of a hydrophilic binder.
Claim 5
Dependent Claim
61 words
The method according to claim 1 in which in the first step the solid carbon is added to the sintering materials in an amount of less than 70% of the solid carbon added in both steps, and in said second step the remaining solid carbon containing water, or a hydrophilic binder is added to the resulting material of the first step.
Claim 6
Dependent Claim
29 words
The method according to claim 4 in which the water is contained in the solid carbon in an amount of 5% to 20% by weight of the solid carbon.
Claim 7
Dependent Claim
17 words
The method according to claim 1 in which a hydrophilic binder is added in the second step.
Claim 8
Dependent Claim
20 words
The method according to claim 1 in which a hydrophilic binder is added in both said first and second steps.
Claim 9
Dependent Claim
17 words
The method according to claim 6 in which the solid carbon is a coke or coke breeze.
Claim 10
Dependent Claim
17 words
The method according to claim 7 in which the solid carbon is a coke or coke breeze.
Claim 11
Dependent Claim
27 words
The method according to claim 4 in which the hydrophilic binder is added in an amount equal to or less than the amount of the solid carbon.
Claim 12
Dependent Claim
147 words
In a method for preliminarily treating sintering materials containing fine powder of a particle size of less than 125μ in the range 15% to 35% the steps comprising subjecting in a first treatment step a mix component consisting of powdery or fine powdery iron ore, fluxing materials, dust recovered from steel-making operations and return fines from a sintering operation to mixing, moisture adjustment and pseudo granule formation operations, and in a second treatment step adding to the material resulting from said first step solid carbon containing water or a hydrophilic binder, and mini-pellets at least 75% of which are of a size of 1 to 7 mm the mini-pellets being added in an amount of 3% to 15% by weight of the materials present other than coke, return fines and hearth layer, and thereafter effecting in said second step, mixing, moisture adjustment and pseudo granule formation operations.
Claim 13
Dependent Claim
147 words
In a method for preliminarily treating sintering materials containing fine powder of a particle size of less than 125μ in the range 15% to 35% the steps comprising subjecting in a first treatment step a mix component consisting of powdery or fine powdery iron ore, fluxing materials, dust recovered from steel-making operations and return fines from a sintering operation to mixing, moisture adjustment and pseudo granule formation operations, and in a second treatment step adding to the material resulting from said first step solid carbon containing water or a hydrophilic binder, and mini-pellets at least 75% of which are of a size of 1 to 7 mm the mini-pellets being added in an amount of 3% to 15% by weight of the materials present other than coke, return fines and hearth layer, and thereafter effecting in said second step, mixing, moisture adjustment and pseudo granule formation operations.
Claim 14
Dependent Claim
28 words
The method according to claim 11 in which water is contained in the solid carbon in an amount of 5% to 20% by weight of the solid carbon.
Claim 15
Dependent Claim
27 words
The method according to claim 11 in which the hydrophilic binder is added in an amount equal to or less than the amount of the solid carbon.
References Cited (Backward Citations)
US3489549A
Cited
US3689249A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |