高炉でのスラグ, 銑鉄間へのSi, MnおよびSの分配比による炉内下部領域の状態の判定

Abstract

At the blast furnace hearth, the equilibrium of the partitioning reactions of Si, Mn, and S between the slag and iron is proved not to be attained. Furthermore, the analytical studies of operational data and sample from working furnace indicate that Si transfer to iron occurs at the lower region above the tuyere level through SiO gas, and those of Mn to iron and S to slag occur as slag-metal reactions in the slag layer at the hearth.The attainments of the reaction equilibrium indicate the condition of the lower part of the furnace and are expressed as follows; RSi= (LSi/L°Si) ·100, RMn= (LMn/L°Mn) ·100, and RS= (LS/L°S) ·100, Where Li is the partitioning ratio calculated from the practical data and L°i the equilibrium ratio. The index Rsi shows the thermal intensity around tuyere level suggesting the height of melting zone. The indices RMn and Rs show the oxygen influence in the hearth suggesting the amount of FeO entered as unreduced. In addition to these the iron temperature shows the thermal intensity in the hearth.The furnace operation during a half year at Chiba Works, Kawasaki Steel Corporation has been clearly explained by the use of these indices.