焼結層内融液生成が鉄系凝結材の酸化反応に与える促進効果

抄録

This study has been performed to understand the reactions of metallic iron and ferrous components in the iron ore sintering bed for utilizing them as agglomeration agent, which relates to the reduction of CO₂ emissions. Effects of size of metallic iron particles and pre-heating temperature on sintering phenomena were examined. Changes in the structure and pressure drop of the bed were observed by using laboratory-scale sintering simulator.
When using larger size of metallic iron particles, pressure drop of the bed did not significantly change. On the contrary, it changed drastically when using metallic iron with smaller particle sizes. Such behaviors are attributed to formation of dense iron oxide layer on the surface of the coarse iron particles, which does not melt due to the shortage of heat. In the case using medium metallic iron particles at higher preheating temperature than 900°C, formed iron oxide tended to melt and oxidation reaction of metallic iron was proceeded. In the case of lower preheating temperature than 900°C, however, the oxidation of metallic iron was suppressed by the oxide layer formed on the surface. Melting of such layer is necessary to be continuously oxidized for metallic iron particle. The additional heat by other agglomeration agents such as coke was required enhance the melting of the iron oxide layers formed on the surface of metallic iron particles with larger size. This suggests that the melting of formed oxide layer is essential for further oxidation of metallic iron oxide particles used as agglomeration agent.