转底炉直接还原铜渣回收铁、锌技术

采用转底炉直接还原工艺,将铜渣含碳球团在高温条件下直接还原得到金属化球团和高品位氧化锌粉尘,再通过熔分或磨矿磁选方式将铁回收,得到的铁产品可作为冶炼含铜钢的原料.转底炉中试结果表明:采用"转底炉直接还原—燃气熔分"流程处理铜渣,可获得TFe品位94%以上、铁回收率93%以上的熔分铁水;采用"转底炉直接还原—磨矿磁选"流程处理铜渣,可获得TFe品位90%以上、铁回收率85%以上的金属铁粉;采用两种流程处理铜渣,均可获得锌品位60.02%的ZnO粉尘.结果表明,经过转底炉直接还原,铜渣中的铁橄榄石Fe_2SiO_4和磁铁矿Fe_3O_4相转变为含有金属铁Fe、二氧化硅SiO_2和少量辉石相Ca(Fe,Mg)Si_2O_6的金属化球团,具备通过磨选或熔分进行进一步富集的条件.

Technology of recovery of iron and zinc from copper slag by RHF direct reduction

By using RHF (Rotary hearth furnace) direct reduction method, the metallized pellets and a high grade zinc oxide dust can be obtained from the carbon bearing pellets of copper slag at a high temperature.The iron can be recovered by melting or grinding/magnetic separation method as a raw material for steel bearing copper.Results of the pilot experiment showed that a molten iron with a purity more than 94% mass can be gained from the copper slag by process of RHF direct reduction and gas melting separation, the recovery ratio is more than 93% mass.An iron powder of more than 90% mass purity can be obtained by process of RHF direct reduction and grinding and magnetic separation,the recovery ratio is more than 85%.A dust of more than 60% mass Zinc can also be gained with the two kinds of process mentioned above.It is believed that after direct reduction in RHF, fayalite (Fe2SiO4) and magnetite (Fe3O4) in the copper slag can be changed into the metallized pellets containing iron(Fe), quartz (SiO2) and a small amount of augite (Ca(Fe,Mg)Si2O6), which can be recovered by the magnetic separation or melting process.