| 摘要 |
[Problem] To propose: a blast furnace operation method in which both the cooling power and combustion quality are improved without increasing the lance outer diameter, making the method effective in improving productivity and reducing the unit consumption of the reducing agent; and a structure of a lance used to carry out this method. [Solution] A blast furnace operation method in which at least a solid reducing agent and a combustion-supporting gas are blown through a tuyere into the furnace using lances inserted into a blowpipe, wherein: bundle-type lances obtained by bundling a plurality of blowing tubes are used; and when the solid reducing agent is blown alone, the solid reducing agent and the combustion-supporting gas are simultaneously blown, or the solid reducing agent, the combustion-supporting gas, and a gaseous reducing agent are simultaneously blown into the blast furnace through a solid reducing agent blowing tube, a combustion-supporting gas blowing tube, and a gaseous reducing agent blowing tube of the bundle-type lances, two or more of the bundle-type lances are inserted into the blowpipe and the respective tips are brought near each other, and blowing is performed so that the respective blowout flows interfere with each other within the blowpipe. |
