公开(公告)号：US20240068060A1

公开(公告)日：2024-02-29

申请号：US18271612

申请日：2021-12-09

Applicant: JFE STEEL CORPORATION

Inventor： Hidemitsu NEGISHI ,  Shota AMANO ,  Yumi MURAKAMI ,  Futoshi OGASAWARA ,  Kenji NAKASE

IPC: C21C5/32 ,  C21C1/02 ,  C21C1/04 ,  C21C5/46 ,  F27D3/16

CPC classification number: C21C5/32 ,  C21C1/02 ,  C21C1/04 ,  C21C5/46 ,  F27D3/16 ,  F27D2003/163

Abstract: Proposed is a molten iron refining method capable of securing an in-flame staying time period of a heat transfer medium without being influenced by height adjustments of a blowing-purpose oxygen-blowing lance. As far as to a position lower than an upper end inside a converter-type vessel 1, a blowing-purpose oxygen-blowing lance 3 that supplies oxidizing gas and is capable of ascending and descending and at least one burner lance 4 capable of ascending and descending independently of the blowing-purpose oxygen-blowing lance are inserted. From the blowing-purpose oxygen-blowing lance, either oxidizing gas or oxidizing gas and CaO-containing refining agent are blown onto the molten iron. Also, a flame is formed by causing the burner lance to discharge fuel gas and combustion supporting gas. Powder particles discharged from the burner lance are caused to pass through the flame and to be blown onto the molten iron in a heat-transferred state, so that the molten iron is thermally compensated.

公开(公告)号：US20240060149A1

公开(公告)日：2024-02-22

申请号：US18270600

申请日：2021-12-17

Applicant: JFE STEEL CORPORATION

Inventor： Futoshi OGASAWARA ,  Yudai HATTORI ,  Rei YOKOMORI ,  Ryo KAWABATA

IPC: C21C1/02 ,  C21C5/35

CPC classification number: C21C1/02 ,  C21C5/35

Abstract: A molten iron refining method that prevents a cold iron source from remaining unmelted even under the condition of a high ratio of the cold iron source. An auxiliary material is added, and an oxidizing gas is supplied, to cold iron source and molten pig iron that are contained or fed in converter-type vessel, and molten iron is subjected to refining process. Prior to refining process, a pre-charged cold iron source that is charged all at once into the converter-type vessel before the molten pig iron is charged into the converter-type vessel is charged in an amount not larger than 0.15 times the sum of an amount of the pre-charged cold iron source and a charge amount of the molten pig iron, or is not charged. A furnace-top-added cold iron source that is added from a furnace top of the converter-type vessel is fed into converter-type vessel during refining process.