Influence of Operational Factors on Thermal and Chemical Conditions at Lower Part of Blast Furnace

Abstract

The operational data of blast furnace performance for longer periods are analyzed by the following parameters as adiabatic flame temperature, height for heat exchange and height of melting level, as well as indices of the thermal state R_Si and the reduction behavior of ferrous oxide R_S and R_Mn at the lower part of blast furnace. The results are as follows.
(1) The temperature of melts changes with the adiabatic flame temperature and height for heat exchange, and is related to the heat balance.
(2) R_Si gives the same expression as that for thermal state representing the extent of coke reserve zone.
(3) With lower quality coke, R_Si, R_S and R_Mn decrease markedly even in a regular operation; this indicates increasing FeO content in slag at the hearth.
(4) The increase of sulfur content in injected oil decreases the S distribution ratio between slag and metal. On the other hand, the increase of sulfur content in coke has no influence on it. These differences are caused by the transfer mechanism to gas phase.