铁酸钙氢还原制备球形纳米铁粉的工艺及机理  

Prepared process and mechanism of spherical iron nano-powder by the hydrogen reduction of calcium ferrites

作　　者：张宇奇 高自立 陈新贵 吴爱华 叶楠[2] 吴家景 唐建成[2] ZHANG Yuqi;GAO Zili;CHEN Xingui;WU Aihua;YE Nan;WU Jiajing;TANG Jiancheng(Nanchang Cemented Carbide Limited Liability Company, Nanchang 330013, China;School of Materials Science and Engineering, Nanchang University, Nanchang 330031, China;Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang 330028, China)

机构地区：[1]南昌硬质合金有限责任公司,南昌330013 [2]南昌大学材料科学与工程学院,南昌330031 [3]江西省科学院应用物理研究所,南昌330028

出　　处：《粉末冶金材料科学与工程》2018年第6期640-646,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51864034;51364036);江西省重点研发计划资助项目(20171ACE50018)

摘　　要：以CaO和Fe_2O_3为原料,煅烧出单相CaFe_2O_4粉末、单相Ca_2Fe_2O_5粉末和混合相Ca_2Fe_2O_5/CaO粉末,以此为前驱体,利用氢还原制备纳米铁粉。分析前驱体种类对还原温度、铁粉形貌和粒径的影响,研究铁酸钙氢还原制备球形纳米铁粉的机理。结果表明:随着CaO比例的增加,铁酸钙前驱体的还原温度升高,铁粉的粒径减小,铁粉的形貌由不规则形状逐渐变为球形。Ca_2Fe_2O_5/CaO前驱体经950℃氢还原,得到平均粒径为34 nm的球形铁粉,且粒度分布均匀,分散性较好。CaO在纳米Fe粉制备过程中起分散和促进Fe粉形核的作用。Three kinds of percursors powders including single phase CaFe2O4,single phase CaFe2O4and mixed phase Ca2Fe2O5/CaO were prepared by calcine using CaO and Fe2O3as 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 of34nm are obtained by reducing Ca2Fe2O5/CaO percursor at950℃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.

关 键 词：铁酸钙 氢还原 球形 纳米铁粉 粒径 

分 类 号：TF123.73[冶金工程—粉末冶金]