Abstract Surface morphology evolution in the reduction of fine iron ore in a conical fluidized bed reactor under various conditions was investigated. Regime diagrams of morphology on iron ore reduction with H2 were obtained for choosing appropriate operating condition. The result indicates that it is beneficial to inhibit the formation of iron whiskers under high H2 content, high gas velocity and low reduction temperature. Further, the formation mechanism of the whiskers in the iron ore reduction with H2 atmosphere was revealed by the quantitative analysis of the relative rate between the iron diffusion and reduction. The result indicates that iron diffusion rate is the dominant factor that brings about whiskers during the reduction. Based on the regime diagrams of morphology, the formation of whiskers could be inhibited with the guidance of a whisker formation tendency value below 2.51 m4·mol−1. This provide a method of guidance for the application on iron ore reduction process by adjusting the relative rate between diffusion of iron and reduction.

中文翻译：

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锥形流化床反应器还原细铁矿表面形貌演变机制

摘要 研究了锥形流化床反应器在不同条件下还原细铁矿的表面形貌演变。为选择合适的操作条件，获得了H2还原铁矿石形态的规律图。结果表明，在高H2含量、高气速和低还原温度下有利于抑制铁晶须的形成。此外，通过铁扩散和还原之间的相对速率的定量分析，揭示了铁矿石在氢气气氛下还原时晶须的形成机制。结果表明，铁扩散速率是还原过程中产生晶须的主要因素。基于形态学的状态图，晶须形成趋势值低于 2.51 m4·mol−1 可以抑制晶须的形成。通过调节铁的扩散与还原的相对速率，为铁矿石还原工艺的应用提供了一种指导方法。