2014 年 100 巻 2 号 p. 277-286
Influence of a large amount of hydrogen and traces of sulfur on reaction behavior of the bed with ore pellet and coke particles were examined in a laboratory reaction apparatus with the blast furnace simulated conditions under load until 1400°C.
On the later metallization stage around 1000°C, hydrogen half substitute into base gas N2-CO-CO2 enhanced the reduction and sulfur addition to hydrogen (sulfur chemisorption on iron) enhanced it more. Coke mixing into the bed enlarged further these metallization due to the spacer effect and facilitating the water gasification. These results influenced structures of products to provide more swelling of pellets and those topochemical reaction types for sulfur added reaction gas relatively to the gas without sulfur.
Beyond around 1100°C, reduction processes mostly terminated independently of reaction gas conditions and coke mixing.
The shrinkage with softening of bed was lessened by hydrogen substitute and coke mixing, because of less FeO bearing slag and spacer effect of coke. Sulfur addition enlarged the shrinkage due to promoting iron sintering derived from sulfur bearing slag.
Both conditions of base gas and hydrogen substituted gas with coke mixed bed made the bed melt through iron carburization with CO gas and coke, while sulfur addition suppressed the melting.
Moreover, the reaction behaviors of the bed were overall investigated along with the results of gas pressure drop through the bed and exit gas analysis.
