| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for operating a blast furnace through charging an iron raw material and coke from a furnace top, which can prevent the aggravation of air permeability in the furnace, when replacing a part of the coke with ferrocoke, mixing the iron raw material with the ferrocoke, and charging the mixture from the furnace top. SOLUTION: The method for operating the blast furnace through charging the iron raw material and the coke from the furnace top includes replacing a part of the coke with the ferrocoke which is manufactured by molding and dry distilling the raw material containing coal and iron ore as main components, mixing the iron raw material with the ferrocoke, and charging the mixed iron raw material and the ferrocoke from the furnace top, wherein a coke to be used as the above coke has a harmonic average grain size of 40 mm or larger and a tumbler rotational strength of 84% or higher (at rotation of 400 with index of 6 mm or more), or has the harmonic average grain size of 40 mm or larger and a drum rotational strength of 81% or higher (at rotation of 150 with index of 15 mm or more). COPYRIGHT: (C)2008,JPO&INPIT
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