摘要
对某低品位铁矿直接还原过程中金属铁颗粒的生长和解离特性进行了研究,重点讨论了还原剂用量和还原时间对铁颗粒长大的影响.X射线衍射和扫描电镜分析结果表明:减少还原剂用量能减弱还原气氛,减少结晶中心的生成,有利于铁颗粒的聚集长大,但因为部分铁损失于脉石中,所以限制了铁晶核的进一步长大;延长还原时间能有效地促进铁颗粒的聚集长大,并降低铁产品的活性,防止再氧化;还原矿中非晶态物质的生成以及金属铁和脉石的硬度差异,有利于金属铁颗粒的粗磨单体解离.
The grain growth and cleavage characteristics of metallic phase were studied in direct reduction of a low-grade iron ore. The effects of reducing agent dosage and roasting time on the grain growth were discussed. The results of X-ray diffraction and scanning electron microscopy show that decreasing the reducing agent dosage can limit the reducing atmosphere and restrict the generation of crystallization centers, thereby it is conducive to the grain growth of metallic phase, but the further grain growth is confined due to the partly losing of iron in gangue. Prolonging the roasting time can promote the grain agglomeration and growth, which can decrease the activity of metallic products and thus prohibit the reoxidation reaction. The generation of amorphous substances and the hardness differ- ence between metallic phase and gangue are beneficial to the cleavage of metallic iron when the grinding fineness is coarse.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2011年第9期1048-1052,共5页
Journal of University of Science and Technology Beijing
关键词
铁矿石
直接还原
颗粒生长
解离
iron ores
direct reduction process
grain growth
cleavage
