US4014684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of steel
Assignee: Foseco International Ltd
•
Filing: 1974-11-14
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Granted: 1977-03-29
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Expires: 1994-11-14
Abstract
Abstract The invention is concerned with the desulphurizing of molten ferrous metal by the use of a lime-based flux composition. The composition comprises, by weight, at least 60% of lime and includes from 1 to 20% of sodium carbonate, from 5 to 30% of an alkali metal or alkaline earth metal fluoride, typically fluorspar, and from 5 to 20% of alumina. To desulphurize molten metal the flux is added to the molten metal in a vessel, typically by injecting the flux in particulate form into the molten metal.
Inventors
- 👤 Evan Thomas Richard Jones
- 👤 Robert Anthony Fishburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:52
CPC Classifications
C; C21; C21C; C21C7/00; C21C7/04; C21C7/064; C21C7/0645
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
64 words
A flux composition for use in desulphurising molten metal, which composition comprises, by weight, at least 60% of lime, from 1 to 20% of sodium carbonate, from 5 to 30% of a fluoride selected from alkali metal and alkaline earth metal fluorides and mixtures thereof, from 0 to less than 2% by weight of metallic reducing agent and from 5 to 20% of alumina.
Claim 2
Dependent Claim
64 words
A flux composition for use in desulphurising molten metal, which composition comprises, by weight, at least 60% of lime, from 1 to 20% of sodium carbonate, from 5 to 30% of a fluoride selected from alkali metal and alkaline earth metal fluorides and mixtures thereof, from 0 to less than 2% by weight of metallic reducing agent and from 5 to 20% of alumina.
Claim 3
Dependent Claim
14 words
A flux composition as claimed in claim 1 in which the fluoride is fluorspar.
Claim 4
Dependent Claim
15 words
A flux composition as claimed in claim 1 in which the fluoride is sodium fluoride.
Claim 5
Dependent Claim
18 words
A flux composition as claimed in claim 1, which contains from 60 to 80% by weight of lime.
Claim 6
Dependent Claim
19 words
A flux composition as claimed in claim 1, which contains from 5 to 10% by weight of sodium carbonate.
Claim 7
Dependent Claim
18 words
A flux composition as claimed in claim 1, which contains from 10 to 25% by weight of fluorspar.
Claim 8
Dependent Claim
16 words
A flux composition as claimed in claim 1, which contains from 5 to 15% of alumina.
Claim 9
Dependent Claim
21 words
A flux composition as claimed in claim 1 wherein the metallic reducing agent is selected from aluminium and aluminium containing alloys.
Claim 10
Dependent Claim
25 words
A method of desulphurising molten metal in a vessel, which method comprises adding to the molten metal a flux composition as claimed in claim 1.
Claim 11
Dependent Claim
23 words
A method as claimed in claim 9, wherein a stream of the flux composition in particulate form is injected into the molten metal.
Claim 12
Dependent Claim
27 words
A method as claimed in claim 9, wherein the flux composition in particulate form is injected into the molten metal in a medium containing a reducing gas.
Claim 13
Dependent Claim
33 words
A method as claimed in claim 9, wherein the flux composition in particulate form is injected into the molten metal in a medium containing a reducing gas selected from propane and natural gas.
Claim 14
Dependent Claim
16 words
A method as claimed in claim 9 wherein the metal is selected from iron and steel.
Claim 15
Dependent Claim
13 words
A method as claimed in claim 9 wherein the vessel is a ladle.
Claim 16
Dependent Claim
20 words
A flux composition according to claim 1 consisting essentially of 60-80% lime, 5-10% sodium carbonate, 10-25% fluorospar and 5-15% alumina.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-28 | 1980-09-27 | 1981-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-28 | 1984-09-27 | 1985-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-28 | 1988-09-27 | 1989-03-29 | $7700.00 | Window Closed / Lapsed |