US3807986A
Expired / Lapsed
US
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Combination iron and iron oxide briquette and method of using
Assignee: Lukens Inc
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Filing: 1971-06-09
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Granted: 1974-04-30
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Expires: 1991-06-09
Abstract
Abstract Briquettes, or uniformly sized pieces, formulated according to planned chemical and physical consistencies, introduced by gravity through the slag layer onto, or into, the molten metal bath of an electric arc furnace, during the process of steel making, for refining the metal to a desired steel composition, while making appreciable useful additions to the molten metal bath, by controlling the thermal balance and carbon content of the molten bath, and also shielding, at least in part, the refractory wall of the furnace by causing a vigorous boiling action, with erupting slag plumes, which intervene between the arcs and the refractory wall. The briquette formulations are 8092 percent metallic iron and at least 8 percent iron oxide. The metallic iron may be particulate scrap such as borings, turnings, small chips, or similar material. The iron oxide may be mill scale, beneficiated iron ore, or similar material. Other components will be carbon at about 0.30-2.0 percent, sulfur preferably below 0.06 percent, silica preferably less than 2.0 percent, and alumina, calcium and manganese oxides, etc. The total impurities or gangue preferably should be less than 4.0 percent. The effective density of the briquettes should be about 5.5 grams per cubic centimeter and the mass of an individual briquette should be about 50 grams minimum. The refining is effected by combined control of the rate of introducing, and the time duration of such introduction, of briquettes to the molten metal bath, and the rate of introduction of heat into the molten metal bath by electric energy through carbon electrodes, or by other supplementary means.
Inventors
- 👤 R Smailer
- 👤 W Funk
- 👤 H Jensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:55
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/52; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
19 words
In the process of claim 1, said briquettes containing on the average not more than about 0.060 percent sulfur.
Claim 2
Dependent Claim
19 words
In the process of claim 1, said briquettes containing on the average not more than about 0.5 percent silica.
Claim 3
Dependent Claim
47 words
In the process of claim 1, said briquettes introduced into said steel bath from an opening in the upper part of said furnace by gravity through slag on the top of said steel bath, said briquettes having an effective density of about 5.5 grams per cubic centimeter.
Claim 4
Dependent Claim
20 words
In the process of claim 4 wherein the volume of said briquettes is between about 0.5 and 17.5 cubic inches.
Claim 5
Independent Claim
99 words
A method of reducing refractory wear in an electric arc furnace during the steelmaking process due to severe heating from arc radiation, the method comprising continuously introducing formulated briquettes into the molten steel bath, said briquettes received by said bath causing a vigorous carbon boil in said bath and the erupting of slag plumes which shield the refractory of said furnace at least in part from arc radiation, said briquettes comprising on the average at least 80 percent particulate steel scrap, at least about 8 percent iron oxide, about 0.5 or more percent carbon, incidental impurities and binding material.
Claim 6
Dependent Claim
54 words
A method in accordance with claim 6 wherein the briquettes used in the method are introduced into the molten bath from an opening in the upper part of said furnace by gravity through slag on the top of the molten bath, the briquettes having an effective density of about 5.5 grams per cubic centimeter.
Claim 7
Dependent Claim
25 words
A method in accordance with claim 6 wherein the volume of the briquettes used in the method is between about 0.5 and 17.5 cubic inches.
Claim 8
Dependent Claim
91 words
A formulated briquette for use in a steelmaking process wherein a plurality of such briquettes are introduced into a molten steel bath through a layer of liquid slag on top of the bath, the briquette comprising: at least 50 percent particulate steel scrap, a minimum of about 8 percent iron oxide, a minimum of about 0.30 percent carbon, binding material, and incidental impurities, the briquette having a weight in the range of about 0.05-1 kilogram and a minimum effective density of about 1 1/2 times the density of said liquid slag.
Claim 9
Dependent Claim
19 words
A formulated briquette in accordance with claim 9 wherein the particulate steel scrap content is about 80 percent minimum.
Claim 10
Dependent Claim
64 words
A formulated briquette for use in a steelmaking process which consists essentially of at least 50 percent particulate steel scrap, a minimum of about 8 percent iron oxide substantially as mill scale, a minimum of about 0.30 percent carbon, and incidental impurities, said briquette having a minimum weight of about 80 grams and a minimum effective density of about 5.5 grams per cubic centimeter.
Claim 11
Dependent Claim
85 words
A formulated briquette for use in a steelmaking process to be introduced into a molten steel bath through a covering layer of liquid slag, the briquette essentially consisting of at least 50 percent particulate steel scrap, a minimum of about 8 percent iron oxide substantially as mill scale, a minimum of about 0.30 percent carbon, and incidental impurities, the briquette having a weight of about 0.05-1 kilogram, the minimum effective density of the briquette being about 1 1/2 times the density of said liquid slag.
Claim 12
Dependent Claim
51 words
A formulated briquette for use in a steelmaking process which consists essentially of at least 50 percent particulate steel scRap, a minimum of about 8 percent iron oxide substantially as mill scale, a minimum of about 0.30 percent carbon, and incidental impurities, the weight of the briquette being about 1000 grams.
Claim 13
Dependent Claim
94 words
A formulated briquette for use in a steelmaking process wherein it is introduced into molten steel through a covering of liquid slag, which has a weight in the range of about eighty grams to a kilogram and consists essentially of at least 80 percent particulate steel scrap and a balance of iron oxide and incidental impurities, the particulate steel scrap providing heat conduction through the briquette and the oxide providing oxygen for reaction with available carbon whereby the briquette melts rapidly when charged into molten metal in the melting furnace of the steelmaking process.
Claim 14
Dependent Claim
18 words
A formulated briquette in accordance with claim 14 wherein the particulate steel scrap content is about 80 percent.
Claim 15
Dependent Claim
22 words
A formulated briquette in accordance with claim 14 wherein the effective density of the briquette is about 5.5 grams per cubic centimeter.
Claim 16
Dependent Claim
18 words
A formulated briquette in accordance with claim 14 wherein the weight of the briquette is about 1000 grams.
Claim 17
Dependent Claim
47 words
A readily meltable high density briquette for introduction into molten metal in a steelmaking process which consists essentially of 80-92 percent particulate steel scrap and a balance of iron oxide and incidental impurities, said briquette having an effective density of at least 5.5 grams per cubic centimeter.
Claim 18
Dependent Claim
13 words
A briquette in accordance with claim 18 having at least 0.30 percent carbon.
Claim 19
Dependent Claim
11 words
A briquette in accordance with claim 18 having 0.30-0.55 percent carbon.
Claim 20
Dependent Claim
13 words
A briquette in accordance with claim 18 having less than 0.55 percent silica.
Claim 21
Dependent Claim
20 words
A readily meltable high density briquette for introduction through slag into molten metal in a steelmaking process which comprises about:
Claim 22
Dependent Claim
17 words
A briquette in accordance with claim 22 wherein the sulfur content is not greater than 0.060 percent.
Claim 23
Dependent Claim
18 words
A briquette in accordance with claim 23 wherein the sulfur content is not greater than about 0.030 percent.
Claim 24
Dependent Claim
21 words
A briquette in accordance with claim 22 wherein the volume of the briquette is between about 1 and 20 cubic inches.
Claim 25
Dependent Claim
19 words
A briquette in accordance with claim 25 which is cylindrical in configuration with its diameter greater than its length.
Claim 26
Dependent Claim
74 words
A formulated briquette for use in a steelmaking process which has an effective density of at least about 5.5 grams per cubic centimeter and consists essentially of at least 80 percent particulate steel scrap, at least about 8 percent iron oxide, at least about 0.3 percent carbon, and incidental impurities, the particulate steel scrap providing heat conduction throughout the briquette to promote melting thereof when charged into a melting furnace during the steelmaking process.
Claim 27
Dependent Claim
63 words
A formulated briquette for use in a steelmaking process which is compacted to a minimum effective density of 5.5 grams per cubic centimeter, has a weight in the range of 50-1000 grams, and contains steel turnings which form a heat conductive web throughout the briquette which promotes melting of the briquette when it is charged into a melting furnace during the steelmaking process.
Claim 28
Dependent Claim
12 words
A briquette in accordance with claim 28 which is cylindrical in configuration.
Claim 29
Dependent Claim
21 words
A briquette in accordance with claim 28 wherein the volume of said briquette is between about 1.5 and 17.5 cubic inches.
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) | 1977-04-29 | 1977-10-29 | 1978-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-29 | 1981-10-29 | 1982-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-29 | 1985-10-29 | 1986-04-30 | $7700.00 | Window Closed / Lapsed |