粒度对低品位铁矿石煤基直接还原的影响  

Effects of Particle Size on Coal-based Direct Reduction of Low-grade Iron Ore

作　　者：秦晓萌[1] 孙体昌[1] 邹安华[1] 程帅[1] 蒋曼[1] 徐承炎[1] 寇珏[1] 胡学平[1] 

机构地区：[1]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083

出　　处：《矿冶工程》2011年第4期95-99,103,共6页Mining and Metallurgical Engineering

摘　　要：对某低品位铁矿石直接还原过程中原矿粒度对焙烧效果的影响进行了研究,重点研究了还原剂用量和还原时间在原矿粒度增大时对焙烧效果的作用。结果表明,原矿粒度的增大会小幅降低铁产品的品位,但大幅降低其回收率,增大还原剂用量和延长还原时间均能在一定程度上改善焙烧效果,在原矿粒度小于4 mm时,可取得良好的焙烧指标。SEM和XRD结果显示,随原矿粒度的增大,金属铁的颗粒变小,且主要在焙烧矿颗粒表面生成,在颗粒内部则生成大量的铁橄榄石等难还原物质,在磁选过程中损失于脉石中,进而降低铁的回收率。Studies on the effects of particle size of raw ore on roasting effect during direct reduction of a low-grade iron ore were carried out.The effects of the dosage of reductant and reduction time on roasting effect when particle size of the raw ore increased were mainly researched.The results showed that when particle size of the raw ore increased the grade of iron products slightly decreased but the recovery dramatically decreased.The roasting effect can be improved to a certain extent by increasing the dosage of reductant and extending reduction time.Better roasting index can be obtained when particle size of the raw ore is smaller than 4 mm.The results of SEM and XRD showed that particles of metalic iron became small with the increase of particle size of the raw ore.Metalic iron were mainly generated on the surface of roasting ore particles while a large number of irreducible materials such as fayalite generated in the inner of the particles which were lost in the gangues during magnetic separation and thus decreaed the recovery of iron.

关 键 词：低品位铁矿石 直接还原铁 煤基直接还原 原矿粒度 

分 类 号：TD951[矿业工程—选矿]