US 12,486,548 B2
Method for producing reduced iron
Takanobu Inada, Tokyo (JP); Moritoshi Mizutani, Tokyo (JP); and Yutaka Ujisawa, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/921,654
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed May 13, 2021, PCT No. PCT/JP2021/018156
§ 371(c)(1), (2) Date Oct. 27, 2022,
PCT Pub. No. WO2021/230307, PCT Pub. Date Nov. 18, 2021.
Claims priority of application No. 2020-085078 (JP), filed on May 14, 2020.
Prior Publication US 2023/0167516 A1, Jun. 1, 2023
Int. Cl. C21B 13/00 (2006.01); C21B 13/02 (2006.01)
CPC C21B 13/0073 (2013.01) [C21B 13/02 (2013.01); C21B 2100/28 (2017.05); C21B 2100/40 (2017.05); C21B 2100/64 (2017.05)] 14 Claims
OG exemplary drawing
 
1. A method for producing reduced iron that produces reduced iron by reducing iron oxide charged in a shaft furnace, the method comprising:
wherein a heated gas mixture which contains a reducing gas and a nitrogen gas is blown into the shaft furnace, the reducing gas containing 90 volume % or more of a hydrogen gas, and
wherein, without changing a blow temperature and a blow amount of the hydrogen gas per unit time, the amount of the reduced iron produced per unit time is increased by increasing the amount of the nitrogen gas added.