Decrease of Steelmaking Slag by the Improvement of Hot Metal Dephosphorization in Nippon Steel

摘要

Nippon Steel Corp. (NSC) has three types of hot metal dephosphorization processes; torpedo car, hot metal ladle and basic oxygen furnace (BOF). In this paper, the features of these three types of processes were discussed. Operational data of each processes were analyzed by taking into consideration of the efficiency of dephosphorization and the decrease in the total slag volume. Consequently; it was determined that lowering the initial silicon content and CaO/O, and recycling BOF slag are effective in decreasing the steelmaking slag. However, there are still some operational and economical barriers to the practical use of these processes. In order to promote the practical use, the mechanism of hot metal dephosphorization should be further clarified.