| 摘要 |
[Task] It is to propose a blast furnace operation method effective for attaining the improvement of the productivity and the decrease of specific consumption of a reducing material by establishing the increase of cooling ability and the improvement of combustibility without increasing the outer diameter of the lance as well as the structure of the lance used in the operation of this method. [Solution for task] A method of operating a blast furnace by blowing at least a solid reducing material and a combustible gas into the furnace through tuyeres with a lance inserted into a blowpipe, characterized in that a tube-bundle type lance obtained by bundling a plurality of blowing tubes is used and when only a solid reducing material or two kinds of a solid reducing material and a combustible gas or three kinds of a solid reducing material, a combustible gas and a gaseous reducing material is simultaneously blown into an inside of the blast furnace through a tube for blowing the solid reducing material, a tube for blowing the combustible gas and a tube for blowing the gaseous reducing material in the tube-bundle type lance, two or more tube-bundle type lances are inserted into the blowpipe to approximate their front ends to each other and blowing is performed so that the respective blowout streams interfere with each other in the blowpipe. |
