2001 Volume 41 Issue 4 Pages 325-332
Based on the analysis of tuyere sampling performed in PCR increasing stage of Muroran No. 2 blast furnace of Hokkai Iron & Coke Corporation, examination was made on the influence of ash originated in pulverized coal in high-productivity, high PCR operation upon physical property of dripping slag or packed structure at dead man surface extending from raceway end. The amount of dripping slag with which ash originated in pulverized coal reacts and assimilates is 15–20% of the total amount of dripping slag, and the components of dripping slag distribute in a circumferential direction between inside of raceway and outside of raceway as well as in a radial direction including the inside of raceway and dead man. When PCR is high, high-vicious -1 mm fine at the dead man surface from the vicinity of raceway and high CaO/SiO2 -1 mm fine and dripping slag between raceway and in dead man, with the increase of -3 mm fine, are supposed to be one of the main causes deteriorating the gas and liquid permeabilities at the dead man surface and lowering the dead man temperature. For establishing a technology assuring a stable furnace operation over a long period, it is necessary to take the measures for improving deterioration in gas and liquid permeabilities at the dead man surface due to not only -3 mm fine and unburnt char but also pulverized coal ash.