US 12,378,615 B2
Blast furnace operation method
Kazuhira Ichikawa, Tokyo (JP); Yasukazu Hayasaka, Tokyo (JP); Yohei Kitamura, Tokyo (JP); and Natsuo Ishiwata, Tokyo (JP)
Assigned to JFE STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/921,208
Filed by JFE STEEL CORPORATION, Tokyo (JP)
PCT Filed Apr. 21, 2021, PCT No. PCT/JP2021/016163
§ 371(c)(1), (2) Date Oct. 25, 2022,
PCT Pub. No. WO2021/230027, PCT Pub. Date Nov. 18, 2021.
Claims priority of application No. 2020-085674 (JP), filed on May 15, 2020.
Prior Publication US 2023/0175085 A1, Jun. 8, 2023
Int. Cl. C21B 9/08 (2006.01); C21B 7/16 (2006.01); F27B 1/16 (2006.01); F27D 13/00 (2006.01)
CPC C21B 9/08 (2013.01) [C21B 7/16 (2013.01); F27B 1/16 (2013.01); F27D 13/00 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A method of operating a blast furnace in which air blowing is suspended, wherein at the time of suspension, a height of a surface of a raw material-filled layer is above a blast-furnace tuyere and below a height of an upper end of a blast-furnace bosh, the method including:
after air blowing into the blast furnace is suspended, blowing oxygen or oxygen and a combustible gas into the blast furnace through a burner inserted into a taphole to combust coke remaining inside the furnace and reduce a volume of residues inside the furnace, and
blowing air through the tuyere after new coke is charged to a region where the volume has decreased, wherein
the burner is inserted such that a burner leading end is set at a position of 0.4 in a dimensionless radius that is 0 at a blast-furnace axial center part and 1 at a blast-furnace hearth wall surface.