To provide a method for operating a blast furnace with which even in high ratio level of pulverized fine coal Si in molten iron can surely be reduced while reducing the unevenness of Si in the molten iron by stabilizing the blowing quantity of flux into the blast furnace without generating the variation of pressure in a blowing piping of mixed powdery materials and the clogging of the piping.
In the blast furnace operating method for blowing the mixed powdery materials of pulverized fine coal and powdery flux through a blast furnace tuyere, the coal and the flux containing oxide of one or more kinds selected from group composed of CaO, MgO and iron oxide, are mixedly pulverized by adjusting a blending ratio and a pulverizing time. Then, a fluidity index FI (index obtained by synthetically valuating four kinds of values of an angle of repose, a compressing degree, a spatula angle and a condensed degree or a uniformed degree proposed by Mr. Carr) of the mixed powdery materials is ≥ 30.
MATSUI YOSHIYUKI
| JPH03243704A | 1991-10-30 | |||
| JPH03215619A | 1991-09-20 | |||
| JP2002275512A | 2002-09-25 | |||
| JPH04224610A | 1992-08-13 |
Makoto Suhara
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