Influence of Phase Transitions on the Macrokinetics of the Gaseous Reduction of Iron Oxide
- Авторлар: Teplov O.1
-
Мекемелер:
- Baikov Institute of Metallurgy and Materials Science
- Шығарылым: Том 2018, № 1 (2018)
- Беттер: 14-18
- Бөлім: Article
- URL: https://journals.rcsi.science/0036-0295/article/view/172163
- DOI: https://doi.org/10.1134/S0036029518010123
- ID: 172163
Дәйексөз келтіру
Аннотация
The reduction of magnetite pellets is studied by thermogravimetry in a hydrogen flow upon linear heating. A multiple decrease in the reduction rate is observed at the degrees of metallization higher than 70% in a temperature range of 920–950°C. The observed effect of a decrease in the reduction rate by four to five times on heating is related to the α → γ phase transition of iron. Temperature cycling (heating–holding–heating–holding…) in the phase transition range shows that this effect is reversible; i.e., the reduction rate increases on cooling, unlike that on heating. The average temperature of the beginning of the effect in heating–cooling cycles (913°C) turns out to be close to the thermodynamic temperature (911°C) of the α → γ phase transition of iron. Isothermal studies of the reduction rate of pellets in a temperature range of 900–1000°C also confirm this phenomenon. The effect of a decrease in the reduction rate is assumed to appear due to a decrease in the effective coefficient of gas diffusion in γ-iron as compared to α-iron.
Негізгі сөздер
Авторлар туралы
O. Teplov
Baikov Institute of Metallurgy and Materials Science
Хат алмасуға жауапты Автор.
Email: oleg.a.teplov@gmail.com
Ресей, Leninskii pr. 49, Moscow, 119991