open access

https://hdl.handle.net/2115/81337

Faster Generation of Nanoporous Hematite Ore through Dehydration of Goethite under Vacuum Conditions

英語

porous ore

2021-05-17

一般社団法人 日本鉄鋼協会 (The Iron and Steel Institute of Japan)

ISIJ international

61(1)

493-497

Goethite (FeOOH)-based ore has become attractive to be utilized in ironmaking. As mildly dehydrated to remove its high combined water (CW), it changes to a nanoporous hematite ore. The nanopore contributes a significant increase in ore reduction reactivity due to the nanocontact between iron oxide and reducing agents such as C, CO, or H-2. However, the long dehydration time of goethite ore is still one problem. This study revealed the effect of vacuum condition on the mild-dehydration of goethite-based ore significantly reduces the ore dehydration time. The dehydration is finished within one hour at 300 degrees C under high-vacuum condition (P=1.7 Pa), producing nanoporous hematite ore that is similar to under atmospheric one for 24 h. However, no significant decrease in the dehydration temperature under the high-vacuum condition. In contrast, in-situ heating TEM observation reveals that nanopore generation can occur at low temperatures under ultra-high vacuum conditions (P = 5.6 x 10(-6) Pa). Slit pore generates at low temperatures that then eventually disappear by merging to bigger pores at the higher temperatures.

学術雑誌論文

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