锌浸渣还原焙烧-磁选回收铁

Recovery iron from zinc leaching residues by reduction roasting and magnetic separation process

在查明锌浸渣工艺矿物学的基础上,采用还原焙烧将铁酸锌分解为氧化锌和磁性氧化铁,再通过磁选的方法回收铁,达到锌、铁分离的目的。实验考查了焙烧温度、焙烧时间、还原剂用量对铁酸锌分解率、铁回收率和铁品位的影响。结果表明:在焙烧温度为950℃、焙烧时间为1 h及还原剂添加量为10%和5%的条件下,铁酸锌分解率达到72.05%,铁回收率可达到91.79%,精矿中铁的品位为50%左右。焙烧及磁选过程中颗粒的团聚包裹是铁精矿品位不高的主要原因。

Based on the process mineralogy, the zinc ferrite was decomposed into zinc oxide and ferroferric oxide by reduction roasting, and then recovery iron by magnetic separation. The effects of roasting temperature, roasting time and usage of reducing agent on the decomposition rate of zinc ferrite and recovery rate of iron were investigated. The results show that the decomposition rate of zinc ferrite reaches 72.05% and the recovery of iron reaches 91.79% after roasted at 950℃ for 1 h in 10% or 5% reducing agent. The iron concentrate grade only reaches 50%. The agglomeration of particles in the process of roasting and magnetic separation leads to the lower grade.