Reduction behavior of hematite in the presence of coke
The reduction kinetics of hematite in the presence of coke as a reductant was studied via isothermal and non-isothermal thermodynamic analyses. The isothermal reduction of hematite was conducted at a pre-determined temperature ranging from 1423 to 1573 K. The results indicated that a higher reductio...
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| Published in | 矿物冶金与材料学报：英文版 Vol. 23; no. 11; pp. 1244 - 1251 |
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| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
2016
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| Subjects | |
| Online Access | Get full text |
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| Summary: | The reduction kinetics of hematite in the presence of coke as a reductant was studied via isothermal and non-isothermal thermodynamic analyses. The isothermal reduction of hematite was conducted at a pre-determined temperature ranging from 1423 to 1573 K. The results indicated that a higher reduction temperature led to an increased reduction degree and an increased reduction rate. The non-isothermal reduction of hematite was carried out from room temperature to 1573 K at various heating rates from 5 to 15 K·min~（-1）. A greater heating rate gave a greater reduction rate but decreased reduction degree. With an increase in temperature, both the reduction rate and the reduction degree increased at a smaller rate when the temperature was less than 1150 K, and they increased at a higher rate when the temperature was greater than 1150 K before completion of the reduction reaction. Both the isothermal and the non-isothermal reduction behaviors of hematite were described by the Avrami–Erofeev model. For the isothermal reduction, the apparent activation energy and pre-exponential factor were 171.25 kJ ·mol~（-1） and 1.80 × 10~5 min~（-1）, respectively. In the case of non-isothermal reduction, however, the apparent activation energy and pre-exponential factor were correlated with the heating rate. |
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| Bibliography: | hematite ore reduction reduction kinetics coke 11-5787/TF The reduction kinetics of hematite in the presence of coke as a reductant was studied via isothermal and non-isothermal thermodynamic analyses. The isothermal reduction of hematite was conducted at a pre-determined temperature ranging from 1423 to 1573 K. The results indicated that a higher reduction temperature led to an increased reduction degree and an increased reduction rate. The non-isothermal reduction of hematite was carried out from room temperature to 1573 K at various heating rates from 5 to 15 K·min~（-1）. A greater heating rate gave a greater reduction rate but decreased reduction degree. With an increase in temperature, both the reduction rate and the reduction degree increased at a smaller rate when the temperature was less than 1150 K, and they increased at a higher rate when the temperature was greater than 1150 K before completion of the reduction reaction. Both the isothermal and the non-isothermal reduction behaviors of hematite were described by the Avrami–Erofeev model. For the isothermal reduction, the apparent activation energy and pre-exponential factor were 171.25 kJ ·mol~（-1） and 1.80 × 10~5 min~（-1）, respectively. In the case of non-isothermal reduction, however, the apparent activation energy and pre-exponential factor were correlated with the heating rate. |
| ISSN: | 1674-4799 1869-103X |