SUSPENDING METHOD OF BLAST FURNACE

PROBLEM TO BE SOLVED: To provide a suspending method of a blast furnace, in which slag discharge failure at an early stage of start-up (at low temperature) from a suspended state is prevented by predicting molten an iron temperature immediately before suspending of the blast furnace, estimating the Si content in molten iron from the molten iron temperature, and adjusting the amount of silica (SiO) to correspond to the Si content, thereby suppressing increase in slag basicity.SOLUTION: A suspending method of a blast furnace comprises: setting a molten iron temperature before suspending to an average molten iron temperature during a period of 6-10 hr prior to the suspending of the blast furnace; estimating the Si content of molten iron during a period from 6 hr. prior to the suspending to immediately before the suspending based on the set molten iron temperature; and, based on the estimated value of the Si content in the molten iron, charging auxiliary materials yielding a calculated input amount of SiOrequired for individual charges so that slag basicity (CaO/SiO) reaches a target value (1.0 to 1.2), thereby suppressing increase in the slag basicity.