JPS5481110A - Blast furnace operating method - Google Patents

Abstract

PURPOSE:To provide the subject method comprising providing sondes for forming iron ore-cokes mixed layers along the peripheral direction at positions below the level of the chargeding matter at the top part of a blast furnace, thereby to secure the desired gaseous flow quantity at the root part of the furnace fusing zone and prevent the enlargement of the root part to improve in the gas utilization and reduce thermal loss. CONSTITUTION:A number of sondes 17 are inserted in the charged material along the peripheral direction at the level below the charged material line SL at the top portion of a blast furnace. A layer prepared by mixing an ore layer 2 with a cokes layer 3 is formed at a distance l from the furnace wall. When this mixture layer drops in the furnace and reaches the fusion zone forming level, ores are softened to form the fusion zone. However, since cokes are mixed therein, a certain degree of porosity can be secured. Accordingly, the furnace gas is easily passable through the fusion zone, and hence even when the core/cokes ratio is increased, the furnace gas flows through the fusion zone root part 23, melting and dropwise falling of the funsion zone 5 proceed, and the root part 3 is enlarged and prevents occurrence of any trouble in the furnace.