Abstract: Based on thermodynamic calculation,oper- ating data and experiments,Si transmission in B.F. is described in this paper.The Si in hot metal is con- trolled by both reduction and reoxidation.Equilib- rium calculation gives a tapping value and the pro- file of Si content of the hot metal in B.F.The first important factor to control Si content is reaction temperature.The coke reactivity and solution loss are more sensitive to in-situ coke reduction and Si content.

Key words: Si-content, blast furnace, thermodynamics