The influence of V₂O₅ of iron ore during oxidation process was examined by thermogravimetric analysis using a non-isothermal thermogravimetric analysis technology. The oxidation process could be divided into two stages. The kinetic mechanism and apparent activation energy (E) were studied using the Coats–Redfern (C–R) method. The obtained results showed that diffusion model was the best mechanism describing effectively oxidation process of iron ore under different V₂O₅. The values of E showed a decreasing trend with the increase of V₂O₅ addition in the whole oxidation process, indicating that the V₂O₅ was conducive to improve the oxidation kinetic conditions. And the fluctuation amplitude of E at stage II (10.489 kJ/mol) was greater than that at stage I (4.019 kJ/mol). With the amount of V₂O₅ increasing, microstructure study of pellets indicated that the growth pattern of grains was disrupted, resulting in abnormal grain growth and an increase in porosity. Thus, the loose structure of pellets could facilitate the internal diffusion of reaction gas at this moment. The oxidation kinetic conditions were improved and the values of E decreased ultimately.

Graphical Abstract

Oxidation kinetic analysis of the iron ore with different V₂O₅ additions.

中文翻译：

---

V2O5 在球团氧化焙烧过程中的影响：非等温动力学分析和微观结构演化

采用非等温热重分析技术，通过热重分析研究了铁矿石氧化过程中V ₂ O ₅的影响。氧化过程可分为两个阶段。使用 Coats-Redfern (C-R) 方法研究了动力学机制和表观活化能 ( E )。结果表明，扩散模型是有效描述不同V ₂ O ₅条件下铁矿石氧化过程的最佳机制。整个氧化过程中，随着V ₂ O ₅添加量的增加， E值呈下降趋势，表明V ₂ O ₅有利于改善氧化动力学条件。并且阶段II的E波动幅度（10.489 kJ/mol）大于阶段I的波动幅度（4.019 kJ/mol）。_{随着V 2} O ₅含量的增加，球团矿的微观结构研究表明，晶粒的生长模式被扰乱，导致晶粒生长异常和孔隙率增加。因此，颗粒的松散结构有利于此时反应气体的内部扩散。氧化动力学条件得到改善， E值最终下降。

图形概要

_{不同V 2} O ₅添加量的铁矿石的氧化动力学分析。