Fe_2O_3团粒还原制备中空铁颗粒

Preparation of hollow iron particle by reducing Fe_2O_3 aggregate

采用喷雾造粒制备Fe2O3空心球团粒,团粒经过氢气还原得到中空Fe颗粒,通过扫描电镜(SEM)观察Fe2O3空心球团粒及其截面的形貌,研究还原时间对Fe颗粒形貌与截面形貌的影响;采用激光衍射粒度分析仪对Fe颗粒进行粒径分析;采用比表面及孔隙度分析仪表征Fe颗粒的比表面积;采用CSM-MCT显微硬度仪测量空心球状Fe颗粒球壁的硬度和弹性模量。结果表明:Fe2O3空心球团粒和Fe颗粒均为多孔中空球状结构,球壁上存在大量微孔,中空孔直径和球颗粒直径的比值在0.4～0.5;在650℃下还原,随着还原时间增加(4,5,6 h),球壁晶粒逐步长大,中空球状Fe颗粒的比表面积和粒径逐步减小,球壁趋向致密,硬度和弹性模量提高。

Iron particles were prepared by hydrogen reducing hollow Fe2O3 spherical aggregate which was prepared by spray granulation.The morphologies of Fe2O3 aggregate and its cross-section were investigated by SEM.The effect of reductive time on morphology of iron particle was also studied.Specific surface area was measured by surface area and porosity analyzer.The hardness and elasticity modulus of hollow spherical iron particle wall were tested by CSM-MCT micro-hardness instrument.The results indicate that the Fe2O3 spherical aggregate and iron particle are porous hollow spherical structure,there are a lot of pores in the wall of particles,the ratio of hollow radius and the spherical particle radius is between 0.4 and 0.5.With the increase of reductive time at 650 ℃,the grain size of the spherical particle wall increases,both of particle size and specific surface area of iron powder particles decrease,the wall of the hollow sphere tends to compact,and hardness and elasticity modulus increase.