煤泥对浸锌渣的直接还原作用  

Direct reduction effect of coal slime on zinc-leaching residue

作　　者：杨慧芬[1] 蒋蓓萍 王亚运[1] 苑修星 张莹莹[1] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083

出　　处：《中国有色金属学报》2015年第1期250-257,共8页The Chinese Journal of Nonferrous Metals

摘　　要：以煤泥为新型还原剂,探索了煤泥用量、Ca O与Si O2摩尔比、焙烧温度以及焙烧时间等工艺参数对浸锌渣中铅、锌、铁化合物直接还原的影响,分析不同直接还原温度下还原产物,即焙砂中所含矿物的种类及铁的存在物相,观察最佳还原条件下焙砂中铁颗粒的形貌,最后进行了焙砂的磨矿-磁选试验。结果表明:在煤泥用量45%、Ca O与Si O2摩尔比1.2、经1250℃直接还原90 min后,浸锌渣中锌和铅的挥发率分别达到96.69%和97.65%,焙砂中铁的金属化率达到97.78%。铁在焙砂中主要以金属铁颗粒的形式存在,其嵌布粒度多数>2 0μm,金属铁颗粒与渣相界面分明,表明可通过磨矿实现单体解离。采用二段磨矿-磁选流程,可同时获得含铁90.80%的金属铁粉和含铁65%的铁精矿,铁的总回收率为81.19%。由此证明煤泥是一种还原效果优良的浸锌渣还原剂。The effects of technical parameters, such as the mass ratio of coal slim to zinc-leaching residue, the mole ratio of CaO to SiO2, reduction temperature and time, on the direct reduction of zinc-leaching residue containing zinc, lead and iron compounds were explored using coal slime as a new reducing agent. The types of minerals and iron phase in roasted products generated at different temperatures were analyzed. The morphologies of iron particles in calcine were observed under the optimum reduction condition. Finally, the grinding-magnetic separation tests of the calcine were carried out. The results show that the roasted products with evaporation rates of zinc 96.69% and lead 97.65% in the zinc-leaching residues, metallization rate of iron 97.78% are obtained under optimum conditions of the ratio of coal slim to zinc-leaching residues 45%, mole ratio of CaO to SiO2 1.2, direction reduction at 1250℃ for 90 min. The iron in calcine is basically metallic iron. The metallic iron particles size is more than 20μm. The obvious boundaries can be observed between the metallic iron particles and slag phase, showing the feasibility of monomer dissociation of metallic iron particles. The metallic iron powders with iron grade of 90.80% and iron concentrate with iron grade of 65% are synchronously recovered by two stage grinding-magnetic separation process, and the total iron recovery is 81.19%. Therefore, the coal slime is proved to be a good reducing agent for the direct reduction of zinc-leaching residue. Therefore, the coal slime is proved to be a good reducing agent for the direct reduction of zinc-leaching residue.

关 键 词：煤泥 还原剂 浸锌渣 直接还原 有价金属 

分 类 号：TD981[矿业工程—选矿] TF09[冶金工程—冶金物理化学]