高炉灰为还原剂对海滨钛磁铁矿直接还原焙烧磁选--钛铁分离的影响

摘要

The feasibility and mechanisms of using the blast furnace dust as a reductant in direct reduction-low intensity magnetic separation of Indonesian seaside titanomagnetite were investigated. The results show that the blast furnace dust can be used as an alter-native to coal as a reductant under the condition of fluorite as an additive. Under the synergistic effect of the blast furnace dust and flu-orite, the recovery and grade of iron in the reduction iron powder can be increased and the content of TiO2 can be decreased at the same time during the direct reduction process. Simultaneously, iron in the blast furnace dust can also be recovered. A comparison of three different kinds of blast furnace dusts indicates that the composition of the blast furnace dust can influence the effect of reduction. Under the same dust dosage, the Jinxin blast furnace dust ( referred to as JX) show the best reduction performances. The optimum conditions of roasting reduction are the blast furnace dust dosage of 30%, the fluorite dosage of 10% and reduction at 1250℃ for 60 min. The reduction iron powder, with 91. 28% Fe grade, 0. 93% TiO2 content and 89. 19% total iron recovery including iron in the run-of-mine and blast furnace dust, is obtained after the roasted product is processed by using a process of two-staged grinding and two-staged magnetic separation.%对高炉灰在直接还原焙烧-弱磁选工艺中用作印尼某海滨钛磁铁矿还原剂的可行性及其机理进行研究.结果表明,以萤石为添加剂的条件下,高炉灰可代替煤做还原剂,通过高炉灰与萤石的共同作用,可以在直接还原过程中提高还原铁粉中铁的回收率及品位并降低TiO2质量分数,同时回收高炉灰中铁.三种不同产地高炉灰还原效果的比较表明,高炉灰性质对还原效果有影响.在相同用量条件下,津鑫高炉灰( JX)还原效果最好；在JX高炉灰用量30%、萤石用量10%、焙烧温度1250益以及焙烧时间为60 min时,焙烧产物通过两段磨矿和两段磁选,最终得到最佳的还原铁粉中铁品位为91.28%,TiO2质量分数降至0.93%,包括海滨砂矿和高炉灰中铁的铁总回收率达到89.19%.