| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for effectively reducing spitting by setting appropriate conditions of the number and arrangement of bottom blown tuyeres, considering the relation with a collision point against a bath surface of oxygen jet from a top blown lance.SOLUTION: By using a top and bottom blown converter 1 which includes an oxygen top blown lance 4 including nozzles of which each central axis forms the same angle &thetas; to the central axis of the lance at the end, and tuyeres 2 provided in the same number as the nozzles provided on the furnace bottom 3, and by adjusting the angle &thetas; of the oxygen top blown lance 1 and the distance from the end of the oxygen top blown lance 1 to the stationary bath surface of molten iron so as to satisfy 0.3≤r/R≤0.9 and R=Htan&thetas; for all of the bottom blown tuyeres, the molten iron is subjected to decarburize-refining. Wherein, rrepresents the distance (m) from the center of the furnace bottom X to the center of the tuyere, R represents the distance (m) from the center of the furnace bottom X to the furnace bottom Pjust beneath the intersection point of the central axis of the nozzle and the stationary bath surface of molten iron, H represents the distance (m) from the end of the lance to the stationary bath surface of molten iron, and &thetas; represents the angle (°) formed between the central axis of the lance and the central axis of the nozzle, respectively. |
