| 摘要 |
PURPOSE: To improve the adhesiveness between layers of an old material and fresh material at the time of use of a mud material for closing a tap hole at the time of discharging the molten iron and molten slag in a blast furnace from the tap hole and to improve the service life of the mud material itself. CONSTITUTION: This mud material for closing the tap hole of the blast furnace is formed by adding a proper ratio of a binder to 100 parts main raw material consisting of one or >=2 kinds among alumina, silicon carbide, chamotte, carbon, agalmatotite, clay, silicon nitride, silicon nitride iron and metallic powder. Further, 15 to 400 parts unstabilized zirconia is added in addition to this binder to the main raw material. As a result, the corrosion resistance and wear resistance are improved as compared with the conventional mud materials and the dealing with a blast furnace operation of a high tapping ratio is possible. There is no increase in the bore even if a hole of a large bore is opened from the initial period and the long-term tapping is made possible. The excellent performance capable of tapping the tapping slag in the furnace up to the last with good balance is thus exhibited. |
