Burden melting–dripping behavior and iron-coke strength variation under simulated operation of hydrogen-rich blast furnace

Abstract

The effect of replacing coke with iron coke on iron-ore softening, melting, and dripping in a blast-furnace hydrogen (H2)-rich atmosphere is studied. When H2 content increases from 0% to 100%, the iron-ore softening start temperature decreases and then increases. The softening end temperature rises continuously. H2 promotes ferrous oxide (FeO) reduction; thus, more high-melting-point substances are generated in the slag, the melting start and dripping temperatures trend upward, the melting–dripping range narrows, and the charge permeability improves. Replacing iron coke with ordinary coke, for 0–20% H2, the iron-ore softening start and end temperatures further decrease and increase, respectively. The dripping range rises and narrows, slightly improving the permeability. For H2 >20%, the iron coke has no impact on the iron-ore softening–melting behavior. Compared with coke, the iron coke after reaction has severe dissolution loss and obvious strength reduction, coke should not be completely replaced by iron coke.