Importance

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Abstract

To provide a method for operating a blast furnace with which the combustion efficiency of a solid fuel, such as pulverized coal, is improved, thereby making it possible to improve productivity and reduce CO₂ emissions. Pulverized coal and LNG are blown from an upstream lance configured by a double tube, and oxygen is blown from a downstream lance on the downstream side in a hot air blast direction, so that oxygen used for preceding combustion of the LNG is supplied from the downstream lance, and the pulverized coal whose temperature has been increased by the combustion of the LNG is combusted along with the supplied oxygen. When a direction perpendicular to the hot air blast direction is designated as 0°, and a downstream direction and an upstream direction therefrom in the hot air blast direction are designated as positive and negative, respectively, a blowing direction of the oxygen from the downstream lance with respect to the blast direction ranges from −30° to +45°, and a blowing position of the oxygen from the downstream lance with reference to a position at which the upstream lance is inserted into a blast pipe ranges from 160° to 200° in terms of a blast pipe circumferential direction angle.

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First Claim