Reduction behavior of hematite in the presence of coke
来源期刊：International Journal of Minerals Metallurgy and Materials2016年第11期
论文作者：Ze-hong Wang Guo-feng Li Yong-sheng Sun Ming-zhao He
文章页码：1244 - 1251
摘 要：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 × 105 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.
Ze-hong Wang1，Guo-feng Li1,2，Yong-sheng Sun1，Ming-zhao He3
1. College of Resources and Civil Engineering,Northeastern University2. College of Mining Engineering,North China University of Science and Technology3. CITIC Pacific Mining Management Pty Ltd.
摘 要：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 × 105 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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