ADDITIVE FOR IMPROVING AIR PERMEABILITY INSIDE BLAST FURNACE AND METHOD FOR IMPROVING AIR PERMEABILITY INSIDE BLAST FURNACE USING THE SAME

摘要

PURPOSE: An additive capable of substantially improving air permeability inside blast furnace during blast furnace operation is provided, and a method capable of improving air permeability inside the blast furnace by using the additive is provided. CONSTITUTION: The additive for improving air permeability inside blast furnace is characterized in that the additive is consisted of the same composition as molten iron and has grain size corresponding to 2 to 2.3 times of an average grain size of sintered ore charged into the blast furnace, and the inner part of the additive is formed in a hollow polyhedron shape, wherein the grain size of the additive is 50 to 60 mm, wherein the polyhedron is hexahedron(10), wherein a plurality of vents are formed on the surface of the polyhedron, and wherein 4 to 5 vents(11) are formed on one surface of the additive, and size of the vents is 5 to 7 mm. In a blast furnace operation method for charging sintered ore and coke so that the sintered ore and coke alternately form layers from the top of blast furnace, and injecting pulverized coal into the blast furnace through tuyere, the method for improving air permeability inside the blast furnace comprises the process of charging 1.5 to 2.5 tons per sintered ore layer of the additive which is consisted of the same composition as molten iron and has grain size corresponding to 2 to 2.3 times of an average grain size of sintered ore charged into the blast furnace, and the inner part of which is formed in a hollow polyhedron shape into a position corresponding to 0.45 to 0.8 r in a radius (r) direction from the center of the blast furnace at a time point when sintered ore is charged into the blast furnace, wherein adding time of the additive is when air permeability resistance index of the blast furnace is 1.55 (kg/cm¬2) or more.