Method for producing molten steel
US-12281365-B2 · Apr 22, 2025 · US
Method of dechromizing molten iron and method of manufacturing phosphate fertilizer raw material
US2020239973A1 · US · A1
| Field | Value |
|---|---|
| Publication number | US-2020239973-A1 |
| Application number | US-201816652575-A |
| Country | US |
| Kind code | A1 |
| Filing date | Oct 16, 2018 |
| Priority date | Oct 20, 2017 |
| Publication date | Jul 30, 2020 |
| Grant date | — |
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Abstract
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On molten iron having the P concentration of 2 to 4 mass % and having the Cr concentration of 0.3 to 1.2 mass %, a dechromization treatment is performed by adjusting a basicity (CaO mass %)/(SiO 2 mass %) of slag to greater than 0.1 and 1 or less and supplying an oxygen source with a molten iron temperature falling within a range of 1250 to 1500° C. to manufacture molten iron having the P concentration of 1.9 to 3.8 mass % and having the Cr concentration of less than 0.2 mass %.
First claim
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1 . A method of dechromizing molten iron, comprising: on molten iron having the P concentration of 2 to 4 mass % and having the Cr concentration of 0.3 to 1.2 mass %, performing a dechromization treatment by adjusting a basicity (CaO mass %)/(SiO 2 mass %) of slag to greater than 0.1 and 1 or less and supplying an oxygen source with a molten iron temperature falling within a range of 1250 to 1500° C. and manufacturing molten iron having the P concentration of 1.9 to 3.8 mass % and having the Cr concentration of less than 0.2 mass %. 2 . The method of dechromizing the molten iron according to claim 1 , wherein the basicity of the slag is adjusted by setting an added amount of flux to 25 kg/t or less. 3 . The method of dechromizing the molten iron according to claim 1 , wherein a starting raw material of the molten iron having the P concentration of 2 to 4 mass % and having the Cr concentration of 0.3 to 1.2 mass % is steelmaking slag obtained by dephosphorizing molten iron manufactured in a shaft furnace. 4 . A method of manufacturing a phosphate fertilizer raw material, comprising: on molten iron having the P concentration of 1.9 to 3.8 mass % and having the Cr concentration of less than 0.2 mass % obtained by the method of dechromizing molten iron, comprising performing a dechromization treatment by adjusting a basicity (CaO mass %)/(SiO 2 mass %) of slag to greater than 0.1 and 1 or less and supplying an oxygen source with a molten iron temperature falling within a range of 1250 to 1500° C. on the molten iron having the P concentration of 2 to 4 mass % and having the Cr concentration of 0.3 to 1.2 mass %, further performing a dephosphorization treatment and cooling. 5 . The method of dechromizing the molten iron according to claim 2 , wherein a starting raw material of the molten iron having the P concentration of 2 to 4 mass % and having the Cr concentration of 0.3 to 1.2 mass % is steelmaking slag obtained by dephosphorizing molten iron manufactured in a shaft furnace.
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- What does patent US2020239973A1 cover?
- On molten iron having the P concentration of 2 to 4 mass % and having the Cr concentration of 0.3 to 1.2 mass %, a dechromization treatment is performed by adjusting a basicity (CaO mass %)/(SiO 2 mass %) of slag to greater than 0.1 and 1 or less and supplying an oxygen source with a molten iron temperature falling within a range of 1250 to 1500° C. to manufacture molten iron having the P conc…
- Who is the assignee on this patent?
- Nippon Steel Corp
- What technology area does this patent fall under?
- Primary CPC classification C21C1/04. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Thu Jul 30 2020 00:00:00 GMT+0000 (Coordinated Universal Time) (A1). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).