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首页> 外文会议>International conference on green energy and environmental sustainable development >Impact of mechanical activation of graphite as reductant on the reduction of the iron ore containing niobium in terms of lowering the reaction temperature
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Impact of mechanical activation of graphite as reductant on the reduction of the iron ore containing niobium in terms of lowering the reaction temperature

机译：在降低反应温度方面，机械活化石墨作为还原剂对还原含铌铁矿石的影响

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For the purpose of lowering the reaction temperature, the impact of mechanical activation of graphite as reductant by ball milling on the reduction of iron ore containing niobium in terms of reaction temperature was studied by means of nonisothermal gravimetry (TG), and differential scanning calorimetry (DSC), the reduction mechanism was studied by kinetic simulation, and the thermodynamics and kinetics concerned were theoretically analyzed. Through milling, the intrinsic stratiform structure of the graphite was gradually destroyed, the resultant particles became finer, and specific surface area was increased remarkably. After a certain time for milling, the stratiform structure of the graphite was completely destroyed, the fine particles were agglomerated considerably, which hindered the further increase of the specific surface area. The impact of mechanical activation of graphite as reductant on reduction thermodynamics is the lowering of the threshold temperature for indirect reduction, while on kineics is the decrease of the apparent activation energy and increase of the rate constant, both the direct and indirect reduction were controlled by interfacial chemical reaction, which given by TG, DSC, and kinetic simulation. However, the decrease of the apparent activation energy for direct and indirect reduction ascribed to different reasons: for the former, it is the energy storage for the graphite as reactant caused by milling, for the latter, it is the improved contact of the reactants for gas-solid reaction. However, the impact on indirect reduction is more remarkable compared to that on direct reduction. The results obtained from TG, DSC and kinetic simulation conformed well to the theoretical analysis.
机译：为了降低反应温度，通过非等温重量分析（TG）和差示扫描量热法（ DSC），通过动力学模拟研究了还原机理，并从理论上分析了相关的热力学和动力学。通过研磨，石墨的固有层状结构逐渐被破坏，所得颗粒变得更细，并且比表面积显着增加。研磨一定时间后，石墨的层状结构被完全破坏，细颗粒显着团聚，这阻碍了比表面积的进一步增加。石墨作为还原剂的机械活化对还原热力学的影响是降低间接还原的阈值温度，而对运动学的影响是表观活化能的降低和速率常数的增加，直接还原和间接还原均受控制。界面化学反应，由TG，DSC和动力学模拟给出。但是，直接和间接还原的表观活化能的降低归因于不同的原因：对于前者，这是由于研磨而引起的作为反应物的石墨的能量存储，而对于后者，则是反应物与石墨的接触改善了。气固反应。但是，与直接还原相比，对间接还原的影响更为显着。 TG，DSC和动力学模拟得到的结果与理论分析相吻合。

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