In-situ Observation of the Reduction of Iron Oxides by Solid State Carbon in TEM

• Published in: ISIJ International Vol. 46; no. 7; pp. 1106 - 1107
• Main Authors: Ishikawa, Nobuhiro, Furuya, Kazuo, Mitsuoka, Nayuta, Inami, Takashi
• Format: Journal Article
• Language: English
• Published: Tokyo The Iron and Steel Institute of Japan 2006; Iron and Steel Institute of Japan
• Subjects: Applied sciences; Exact sciences and technology; Metals. Metallurgy; Chemical reduction; Solid state; Iron oxide; Transmission electron microscopy; In situ
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.46.1106

The reduction of iron oxides has been one of the most frequently studied topics in iron smelting. The study on the reduction of iron oxides were generally carried out by examining specimens after the reduction treatments. Such a method has a disadvantage that the state of sample changes during cooling or exposing in air. Transmission electron microscope (TEM) was used for in-situ observation of microscopic analysis. For example, environmental cells that is the capsule enclose specimens with gas-atmosphere such as CO or H to promote the gas-solid reaction in TEM have been developed.) On the other hand, hydrogen ion-implantation was also applied to investigate the reduction process by H) But these studies are focused on reaction between a gas and an iron-oxide. The coke i.e. solid state carbon is used as a reductant in iron industry. The reaction between solid state carbon and iron oxides have been mainly studied using mechanical milling because the contact between an iron-oxide and a solid state carbon could be realized easily. It was clarified that the complicated phenomena existed in the system depending on the location and the distance between an iron-oxide and carbon. But these results were obtained after a milling treatment and in-situ analysis in TEM is impossible in this method because the required size of mechanical milling system is too small. The difficulty is realization of contact between a solid state carbon and an iron-oxide within the size of TEM specimen. The specimen preparation for in-situ observation of the reaction between an iron-oxide and a solid state carbon was developed in this study. We would like to introduce the way of the preparation of the specimen and example of the experimental result of contact between wustite and deposited carbon.