Manufacturing method of iron ore sinter appropriate for shaft furnace

摘要

PURPOSE: A method is provided which manufactures sintered ore so that the sintered ore is appropriate as a raw material for a reducing furnace by selectively using expensive low alumina ore or lowering a reduction degradation ratio to 20% or less without addition of constituents harmful to facility and environment such as chlorine. CONSTITUTION: In a method for manufacturing sintered ore in which the mixture is sintered by charging the mixture into a sintering machine and burning the fuel after mixing iron ore having a particle size of 10 mm or less with subsidiary raw materials comprising limestone, dolomite and serpentine and a fuel which is a mixture of coke breeze and anthracite or totally consisted of anthracite, the method for manufacturing iron ore sinter appropriate for a reducing furnace is characterized in that sintered ore having a reduction degradation ratio of 20% or less is manufactured by mixing the fuel with other raw materials and sintering the mixture after controlling a blending ratio of subsidiary raw materials so that a basicity(a weight ratio of CaO/SiO2) of the sintered ore is 2.3 or more, adjusting an amount of dolomite so that a blending ratio of dolomite is in the range of 3.0 to 6.0 wt.% of the total blending raw materials, and proportionally increasing or decreasing a blending ratio of coke breeze which is a fuel in the range of 3.8 to 4.1 wt.% of the total blending raw materials according to the increase or decrease of the blending ratio of dolomite.