METHOD FOR OPERATING BLAST FURNACE

PROBLEM TO BE SOLVED: To develop a system precisely estimating left pig iron and slag quantities in a blast furnace. SOLUTION: At each time when charged material in the minimum unit on the management is charged in the case of charging the raw material into the blast furnace, calculated molten iron produced quantity and calculated molten slag produced quantity are stored as 'the newest charged material information' and the information from 'the oldest charged material information' to 'the newest charged material information' are converted into the volumes in order and summed up to obtain a theoretical volume value. Further, the actual volume value in the blast furnace just after charging is obtained, and the difference between the actual volume values and the theoretical volume values is calculated, and in the case that this difference is negative, the charged material is made to discharge to the outside of the furnace in order from 'the oldest charged material information' till the difference transforms to become positive, and the discharged calculated molten iron produced quantity and the calculated molten slag produced quantity are summed up, respectively to calculate a theoretical molten iron tapping quantity and a theoretical molten slag tapping quantity. The actual molten iron tapped quantity and the actual molten slag tapped quantity are obtained and the left pig iron quantity in the blast furnace from the difference between the theoretical molten iron tapping quantity and the actual molten iron tapped quantity (the left pig iron quantity = the theoretical molten iron tapping quantity - the actual molten iron tapped quantity), and the left slag quantity from the difference between the theoretical molten slag tapping quantity and the actual molten slag tapped quantity (the left slag quantity = the theoretical molten slag tapping quantity - the actual molten slag tapped quantity), are calculated to manage the left pig iron and slag.