US3704744A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slag use in continuous casting of steel
Assignee: Inland Steel Co
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Filing: 1971-10-22
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Granted: 1972-12-05
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Expires: 1991-10-22
Abstract
Abstract A process of continuous casting of steel in which a layer of a molten synthetic slag about one-half to two inches thick is maintained on the surface of a pool of molten steel in the upper end of the continuous casting mold, and said synthetic slag being a mixture of oxides and fluorides wherein said oxides and fluorides are combined in said slag to provide said slag with a plastic deformation point between about 1,100* F and about 1,700* F in accordance with the following equation: Plastic Deformation (Point (* F.)) 1,540- 1 wt. % (K20+ Na20)14 wt. % (B203)- 54 wt. % (LiF+ Li2O)+ 10 wt. % (CaO+ CaF2)+ 1 wt. % (SiO2), said oxide and fluorides also being combined in said slag to provide said slag with a flowidity between about 2 inches and about 16 inches in accordance with the following equation: Flowidity (inches) 9.4+ 0.02 wt. % (K20+ Na20)+ 0.05 wt. % (B203)+ 0.10 wt. % (CaO+ CaF2)+ 0.32 wt. % (LiF+ Li20)- 0.20 wt. % (SiO2), and said slag having an alumina solubility in excess of 20 percent by wt.
Inventors
- 👤 James W Halley
- 👤 Donald E Grimes
- 👤 Norman T Mills
- 👤 Krishna Rao Yalamanchili
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:24
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/10; B22D11/11; B22D11/111
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
20 words
A process of continuous casting as in claim 1, wherein said molten steel is an aluminum killed low carton steel.
Claim 2
Dependent Claim
15 words
calcium fluoride within a range of 5 per cent to 40 per cent by weight,
Claim 3
Dependent Claim
35 words
A process of continuous casting as in claim 1, wherein said oxide and fluorides prior to addition to said continuous casting mold are heated to form a uniform melt and solidified to form a frit.
Claim 4
Dependent Claim
28 words
an alkali metal compound selected from the group consisting of sodium oxide and potassium oxide within the range of 5 per cent to 30 per cent by weight,
Claim 5
Dependent Claim
27 words
a lithium compound selected from the group consisting of lithium oxide and lithium fluoride within the range of 0.5 per cent to 15 per cent by weight,
Claim 6
Dependent Claim
24 words
A process of continuous casting as in claim 3, wherein said frit is ground into granules prior to addition to said continuous casting mold.
Claim 7
Dependent Claim
34 words
A process of continuous casting as in claim 4, wherein said granules are mixed with about 1 to 10 percent by weight finely divided carbon particles prior to addition to said continuous casting mold.
Claim 8
Dependent Claim
12 words
calcium oxide in an amount up to 40 per cent by weight,
Claim 9
Dependent Claim
13 words
boron trioxide in an amount up to 30 per cent by weight, and
Claim 10
Dependent Claim
37 words
A process of continuous casting as in claim 1, wherein said slag is maintained on the surface of said pool of molten metal as a molten layer having a thickness of from one-half inch to 2 inches.
Claim 11
Dependent Claim
142 words
having the combined amounts of boron trioxides, calcium fluoride and lithium fluoride in excess of 15 per cent by weight, and said oxides and fluorides combined in said slag to provide said slag with a plastic deformation point between about 1,100*F and about 1,700*F in accordance with the following question: Plastic Deformation (Point (*F) ) 1540- 1 wt. % (K2O+Na2O)-14 wt. % (B2O3)-54 wt. % (LiF+Li2O)+10 wt. % (CaO+CaF2)- 1 wt. % (SiO2), and said oxide and fluorides also being combined in said slag to provide said slag with a flowidity between about 2 inches and about 16 inches in accordance with the following equation: Flowidity (inches) 9.4+0.02 wt. % (K2O+Na2O) +0.05 wt. % (B2O3)+0.10 wt. % (CaO+CaF2)+0.32 wt. % (LiF+Li2O)-0.20 wt. % (SiO2) and said slag having an alumina solubility in excess of 20 per cent by wt. of said slag.
Claim 12
Dependent Claim
51 words
A process of continuous casting as in claim 1, wherein said oxides and fluorides have the following as batched chemical analysis: Na2O 15 percent by wt. SiO2 21 percent by wt. CaO 23 percent by wt. CaF2 17 percent by wt. LiF 3 percent by wt. B2O3 21 percent by wt.
Claim 13
Dependent Claim
51 words
A process of continuous casting as in claim 1, wherein said oxides and fluorides have the following as-batched chemical analysis: Na2 O 22.0 percent by wt. CaF2 24.0 percent by wt. SiO2 33.4 percent by wt. CaO 11.0 percent by wt. LiF 7.0 percent by wt. K2O 2.6 percent by wt.
Claim 14
Dependent Claim
56 words
A process of continuous casting as in claim 1, wherein said oxides and fluorides have the following as batched chemical analysis: B2O3 18.0 percent by wt. SiO2 26.4 percent by wt. CaO 31.2 percent by wt. Na2O 12.3 percent by wt. CaF2 8.5 percent by wt. LiF 1.4 percent by wt. Al2O3 2.2 percent by wt.
Claim 15
Dependent Claim
51 words
A process of continuous casting as in claim 1, wherein said oxides and fluorides have the following as batched chemical analysis: B2O3 4.0 percent by wt. Na2O 10.0 percent by wt. CaF2 30.0 percent by wt. CaO 25.0 percent by wt. SiO2 23.0 percent by wt. LiF 8.0 percent by wt.
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) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |