Continuous reduction and phase transformation mechanism of pellets in lumpy zone based on dissected hydrogen blast furnace.

The continuous phase transition phenomena and mechanism of pellets in the hydrogen blast furnace is achieved by dissecting the 40m3 hydrogen blast furnace. The results of the dissection reveal that the lumpy zone extends to the bosh of the hydrogen blast furnace (HBF), while it ends at about 2/3 of the stack in traditional blast furnace. The iron oxide (FeO x) began to appear in the upper stack, while the iron started to appear in the lower stack. The reduction rate and metallization rate at the bosh are measured at 95.18% and 95.54%. The content of ferrous oxide (FeO) decreases significantly (measured at 1.73% at the bosh), resulting in an increase in the melting point of the primary slag and a deterioration of its fluidity. FeO x formed in the upper stack continuously diffuses and merges into the gangue, which affects the subsequent transformation of FeO x. FeO x shows a preference for interacting with SiO 2 , CaO, and MgO, directly influencing the formation of slag in the cohesive zone. These findings offer valuable insights for numerical simulation and research on hydrogen-rich operation. • A 40 m3 experimental hydrogen-rich blast furnace is dissected. • The lumpy zone of hydrogen blast furnace extends to bosh. • The reduction rate and metallization rate at the bosh are 95.18% and 95.54%. • FeO x tends to react with SiO 2 to form high melting point substance. • A mechanism of iron and gangue transformation is proposed. [ABSTRACT FROM AUTHOR]