Abstract: An estimation method of the depositional shape of a charged material inside a blast furnace formed after coke inside the blast furnace is consumed by using a burner when the blast furnace is caused to start up. The estimation method includes estimating the depositional shape of a charged material inside a blast furnace in a blowing down with lowering stock level, estimating a charged region of coke inside the blast furnace from the estimated depositional shape of the charged material inside the blast furnace and from the shape of a solidified layer on a bottom part inside the blast furnace, estimating an amount of coke inside the blast furnace that is consumed by using the burner, and estimating, from the estimated amount of the coke inside the blast furnace, the depositional shape of a charged material inside the blast furnace formed after consumption of the coke inside the blast furnace.

Abstract: To provide a method for producing agglomerated ore, with which reduced iron can be efficiently produced by hydrogen reduction, without the need for preheating raw material and raising the temperature of reducing gas. A method for producing agglomerated ore, the method including sintering a sintering raw material containing an iron-containing raw material and a condensation material in a sintering machine to form a sinter cake, and obtaining agglomerated ore by crushing the sinter cake, in which iron oxide contained in the sinter cake is reduced by distributing a reducing gas through the sinter cake on the sintering machine, to make a degree of reduction of iron oxide contained in the agglomerated ore after crushing 50% or more.

Abstract: Provided is a blast furnace operation method that enables lowering of the reducing agent ratio of a blast furnace. The blast furnace operation method includes injecting pulverized coal through tuyeres of a blast furnace. The method includes adjusting coal containing moisture and volatile matter to form adjusted pulverized coal having a specific surface area within a range of 2 m2/g or more and 1000 m2/g or less, a lower heating value of 27170 kJ/kg or more, and a volatile matter content within a range of 3 mass % or more and 25 mass % or less. The method further includes injecting, through the tuyeres of the blast furnace, pulverized coal in which the adjusted pulverized coal, in a mixing ratio of 10 mass % or more, is mixed.

Abstract: Provided is a blast furnace operation method that enables lowering of the reducing agent ratio of a blast furnace. The blast furnace operation method includes injecting pulverized coal through tuyeres of a blast furnace. The method includes adjusting coal containing moisture and volatile matter to form adjusted pulverized coal having a specific surface area within a range of 2 m2/g or more and 1000 m2/g or less, a lower heating value of 27170 kJ/kg or more, and a volatile matter content within a range of 3 mass % or more and 25 mass % or less. The method further includes injecting, through the tuyeres of the blast furnace, pulverized coal in which the adjusted pulverized coal, in a mixing ratio of 10 mass % or more, is mixed.