Towards coal based continuous steelmaking Part 1 – Iron ore fines and scrap to low carbon steel via melt circulation

Abstract

Integrated iron- and steelmaking is effected by depositing a mixture of powdered coal and iron ore fines onto a moving melt surface without prior agglomeration. The resulting metallised solid raft is propelled out of the ironmaking loop onto the melt surface of the first of two steelmaking loops. By progressively adding oxygen to the gas first produced in ironmaking, decarburisation is conducted not with oxygen directly but rather by CO2 and H2O so that subsurface formation of CO is never permitted, via careful manipulation of the rates of gas phase mass transfer, interfacial chemical kinetics and liquid phase mass transfer. During ironmaking, infiltration of the melt via capillary rise greatly enhances the rate of metallisation. All the endothermic heat is supplied from beneath the circulating melt, which picks up its heat when post-combustion of CO and H2 is completed after gases have first passed through the steelmaking loops.