以无烟煤作还原剂,经过配料、圆盘造球、转底炉直接还原和磨矿-磁选工艺流程,从国内某铜渣中回收铁、锌,先后进行了基础实验和中试研究.所得最佳还原条件为:铜渣∶无烟煤∶石灰石∶工业纯碱=100∶21.5∶10∶1,还原温度1 280℃,还原时间38 min;转底炉排出的金属化球团的磨选条件为:一段磨矿细度-0.074 mm粒级占75.88％,磁场强度143.31 kA/m,二段磨矿细度-0.074 mm粒级占62.89％,磁场强度95.54 kA/m.基于上述条件经过转底炉直接还原流程,金属化球团磁选得到金属铁粉TFe品位92.38％,铁回收率88.39％;布袋收尘系统所得粉尘中氧化锌含量为74.25％.机理研究表明,铜渣中的硅酸铁和磁铁矿经过转底炉还原后转变为金属铁,易于通过磨矿-磁选的方法回收.%The fundamental test and pilot-scale experiment were conducted for recovering iron and zinc from some copper slag obtained at home using a processing flowsheet consisting of blending,disc pelletization,direct reduction in a rotary hearth furnace (RHF) and grinding-magnetic separation,with anthracite as a reductant.The optimum reduction conditions were obtained as follows:copper slag,anthracite,limestone and industrial sodium carbonate in the mass ratio of 100∶21.5 ∶ 10 ∶ 1,the reduction temperature at 1 280 ℃,the reduction time of 38 min.And the conditions for grinding and magnetic separation of metalized pellet discharged from RHF included:a grinding fineness at-0.074 mm 75.88％ for the first stage grinding and magnetic field intensity at 143.31 kA/m,secondary grinding fineness at-0.074 mm 62.89％,with magnetic field intensity at 95.54 kA/m.As a result,the direct reduction process in the RHF with the above-mentioned conditions resulted in an iron powder approaching 92.38％TFe grade at 88.39％ recovery from the magnetic separation of metalized pellets,dust collected in baghouse with zinc oxide content at 74.25％.It is found from mechanism investigation that iron silicate and magnetite in the copper slag are reduced to metallic iron after direct reduction in RHF,thus easy to be recovered by the grinding plus magnetic separation process.
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