Kinetics of Silicon Transfer from Pulverized Coal Injected into Blast Furnace under Intensive Coal Injection

Abstract

With the progress of shifting to operation of intensive coal injection, Si in molten metal tends to increase, and this phenomenon cannot be explained by a conventional estimation model which does not distinguish between coke and pulverized coal on contribution to Si in molten metal. With respect to SiO gasification reactions from SiO₂ in pulverized coal, basic experiments were carried out on SiO(g) generation from pulverized coal char packed in a crucible under flow of reducing gas, and reaction rate was deduced with SiO₂ concentration in pulverized coal ash and slag composition taken into account. Furthermore, with respect to Si transfer in blast furnace, the SiO(g) generation rate derived from pulverized coal under intensive coal injection was evaluated and effects of pulverized coal on Si in molten metal were investigated. Consequently the molten metal [Si] variation associated with changes of pulverized coal brand in an actual furnace is become to be estimated.