铁矿粉气基直接还原过程中铁晶须生长观察
Observation on growth of iron whisker in gas-based direct reduction process of iron ore fines
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摘要: 采用五段式卧式加热炉装置, 对5种粒度范围的巴西CVRD矿粉进行了不同温度、不同气氛条件下的气基直接还原实验, 还原后得到各个条件下具有不同表面颗粒形貌的矿粉样.对还原后的矿粉样进行金属化率检测和扫描电镜下微观形貌观察, 发现不同的还原条件对铁矿粉还原过程中矿粉颗粒形貌及颗粒表面铁晶须的生长状况具有重要影响, 研究发现可以从还原条件来控制矿粉颗粒的还原状况及颗粒表面形貌, 从而改善气基直接还原中的颗粒粘结状况.Abstract: A five-stage horizontal heating furnace was applied to the direct reduction experiment of five different sizes of CYRD ore at different temperatures and atmospheres.The ore samples with different surface particle morphologies under various conditions were obtained after reduction.Metallization rate testing and microstructure analysis were done for them under scanning electron microscopy (SEM). The results show that different reduction conditions have important influence on the morphology of mineral particles and the growth of the iron whiskers on the surface of the particles during the reduction process. Thus the reduction of the ore power particle and the particle surface morphology can be controlled by the control of the reduction conditions. Findings indicate that the reduction condition of the iron ore particles and the surface morphology of the particles can be controlled by the reduction conditions so as to improve the bonding conditions of the particles in the gas-based direct reduction.