Prepared process and mechanism of spherical iron nano-powder by the hydrogen reduction of calcium ferrites [铁酸钙氢还原制备球形纳米铁粉的工艺及机理]

摘要

Three kinds of percursors powders including single phase CaFe 2 O 4 , single phase CaFe 2 O 4 and mixed phase Ca 2 Fe 2 O 5 /CaO were prepared by calcine using CaO and Fe 2 O 3 as raw materials. Nanometer Fe powders were prepared by reducing percursors powders under hydrogen. The effects of the type of percursors on the reducing temperature, the morphology and particle size of Fe powders were studied. The formation mechanism of spherical nanometer Fe powders prepared by reducing calcium ferrite was discussed. The results show that the reducing temperature increases, the particle size of Fe powders decreases and the morphology of Fe powders change from irregular to sphere, with increasing the ratio of CaO. The spherical Fe powders with the average particle size of 34 nm are obtained by reducing Ca 2 Fe 2 O 5 /CaO percursor at 950 ℃ under hydrogen, the particle size distribution is uniform and the didpersity is good. The CaO plays a role in dispersing and promoting the nucleation of Fe powder in the preparation of nano Fe powder. ? 2018, Editorial Office of Materials Science and Engineering of Powder Metallurgy. All right reserved.

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