搅拌流化床中超细氧化铁粉流态化及还原实验研究  

Experimental Study on Fluidization and Reduction of Ultrafine Iron Oxide Powder in an Agitation Fluidized Bed

作　　者：宋乙峰[1] 朱庆山[1] 

机构地区：[1]中国科学院过程工程研究所多相复杂系统国家重点实验室,北京100190

出　　处：《过程工程学报》2011年第3期361-367,共7页The Chinese Journal of Process Engineering

基　　金：国家重点基础研究发展规划(973)基金资助项目(编号:2007C13613502)

摘　　要：在内径50mm的搅拌流化床内进行了平均粒径239nm的氧化铁粉的流态化及氢气还原实验.结果表明,床中氧化铁颗粒以聚团鼓泡形式实现完全流化,最小流化速度为0.025m/s,最大床层膨胀比为2.0.在500℃下用氢气还原该氧化铁粉的反应过程为:Fe2O3→Fe3O4→Fe,Fe颗粒的粒径比Fe2O3小,有颗粒烧结现象,由Fe引起的颗粒烧结和粘结作用可能导致失流.与普通流化床相比,搅拌能使流化时间由3min延长至15min,使失流时样品的金属化率由15%提高至76%.The fluidization and reduction of iron oxide powder with averaged particle size of 239 nm in a 50 mm I.D. agitation fluidized bed were studied. The results showed that the powder in the agitation fluidized bed could be completely fluidized in the form of agglomerate bubbling fluidization. The minimum fluidization velocity was 0.025 m/s and the maximum expansion ratio could reach 2.0. And the reduction of the powder under hydrogen atmosphere at 500℃ was examined. The reduction process followed the order of Fe2O3→Fe3O4→Fe. The particle size of Fe was smaller than that of Fe2O3 and sintering happened among some particles. It might be the sintering and sticking effects resulting from metallic iron that led to the defluidization. Compared with conventional fluidized bed, the fluidization time could be increased from 3 to 15 min and the metallization rate of the products when defluidization occurred could be increased remarkably from 15% to 76% with agitation.

关 键 词：搅拌流化床 氧化铁 超细粉 失流 还原 金属化率 

分 类 号：TF552[冶金工程—钢铁冶金]