润磨强化磁铁矿球团一步法直接还原工艺及机理研究  

One-Step Direct Reduction of Damp Milled Magnetite Concentrate Pellets

作　　者：朱德庆[1] 徐小锋[1] 欧应钦 周围 潘建[1] 

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083 [2]中冶集团长天国际工程有限公司,湖南长沙410001 [3]新疆紫金矿业有限公司,新疆乌鲁木齐830000

出　　处：《钢铁》2007年第10期6-11,共6页Iron and Steel

基　　金：国家教育部高等学校优秀青年教师教学科研奖励基金资助项目(教人司[2000]26)

摘　　要：研究了以新疆高品位磁铁精矿为原料，采用预热球团一步法煤基直接还原工艺制取直接还原铁。在造球前通过润磨工艺预处理磁铁精矿，以期提高生球及预热球强度，有效地降低干球粉末率。在磁铁精矿配加1.0%复合粘结剂及润磨4 min的条件下，生球落下强度由未润磨时的3.8次/0.5 m提高到13.7次/0.5 m；润磨后干球〈1 mm粉末率由未润磨时的10.98%降低到2.98%；在预热温度800℃、预热时间10 min时，预热球团抗压强度由未润磨时的466 N/个提高到581 N/个。预热球团直接还原时，采用润磨预处理方案球团的金属化率与无润磨工艺的相差不大，但金属化球团抗压强度远远大于未润磨时的金属化球团，且几乎不产生磁性粉末。通过链箅机—回转窑直接还原扩大试验，所得的直接还原球团铁品位达93.91%、金属化率达95.99%、硫的质量分数低于0.01%、磁性粉末率仅为0.75%-0.96%、还原煤耗为808.5-859.3 kg/t。The direct reduction of magnetite pellets of 69.21%-70.86% Fet, was conducted. The pellets were made from damp milled concentrate to increase strength of green balls, lower binder dosage and reduce fines generated during drying and handling dried balls. For the magnetite concentrate pretreated by damp milling for 4 min and balling at 7.2% moisture for 15 min,the drop number of green balls were increased from 3.8 times to 13.7 times from 0.5 meters and fines fraction of dried balls was reduced from 10.98% to 2.98%, respectively. The compressive strength of pellets preheated at 800 ℃ for 10 min was raised from 466 Newton to 581 Newton, while the metallization degree was almost the same compared with that made from magnetite concentrate prepared without damp milling. The pilot direct reduction was performed to stimulate grate-kiln process. The results are as follows： Fe, of DRI 93.91%,metallization degree 95.99%, sulphur content lower than 0.01%, magnetic powder rate 0.75%-0.96% and reductant coal rate 808.5-859.3 kg/t. Such DRI is a high quality charge for electric arc furnace steel making.

关 键 词：磁铁精矿 润磨 干球粉末率 预热球强度 回转窑结圈 直接还原铁 

分 类 号：TF55[冶金工程—钢铁冶金]