Faster Generation of Nanoporous Hematite Ore through Dehydration of Goethite under Vacuum Conditions
| Autor: | Tomohiro Akiyama, Ade Kurniawan, Takahiro Nomura, Genki Saito |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Goethite
Materials science Nanoporous Mechanical Engineering Metals and Alloys porous ore Hematite low-grade iron ore medicine.disease vacuum-dehydration Chemical engineering Mechanics of Materials visual_art pore morphology Materials Chemistry visual_art.visual_art_medium medicine goethite Dehydration |
| Zdroj: | ISIJ International. 61:493-497 |
| ISSN: | 1347-5460 0915-1559 |
| DOI: | 10.2355/isijinternational.isijint-2020-403 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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