Method for operation of blast furnace

A method for operation of a blast furnace, the method comprising:

• pulverizing coal to make pulverized coal, and pulverizing iron ore to make pulverized iron ore;
• and
• injecting the pulverized coal and the pulverized iron ore together from a tuyere,
• wherein a loss on ignition of the iron ore is greater than or equal to 9% by mass and less than or equal to 12% by mass,
• wherein an injection rate of the pulverized coal is greater than or equal to 150 kg/tp,
• wherein an injection rate of the pulverized iron ore is greater than or equal to 2.5 kg/tp and less than or equal to 50.0 kg/tp,
• wherein the pulverized coal and the pulverized iron ore, each have a maximum grain size of less than or equal to 1,000 μm,
• wherein a Hardgrove Index of the coal to be pulverized is greater than or equal to 40 and less than or equal to 90,
• wherein the pulverized coal comprises ash comprising 50% by mass or more and 60% by mass or less SiO2, and 20% by mass or more and 30% by mass or less Al2O3,
• wherein a grain size of each of the pulverized coal is equivalent to a grain size of the pulverized iron ore,
• and wherein a pressure loss of the blast furnace reduces in comparison to a pressure loss before the injection of the pulverized iron at said injection rate;
• and a pressure loss change amount of the blast furnace becomes negative.