Optimization of magnetic separation process for iron recovery from steel slag

摘要

To improve the efficiency of iron recovery from steel slag and reduce the wear-and-tear on facilities,a new method was proposed by adding a secondary screen sizer to the magnetic separation process according to grain size distribution of magnetic iron(M-Fe)in the slag.The final recycling efficiency was evaluated by calculating the percentage of recycled M-Fe to the maximum amount of M-Fe that could be recovered.Three types of slags,namely basic oxygen furnace slag,desulfurization slag,and iron ladle slag,were studied,and the results showed that the optimized recovery efficiencies were 93.20%,92.48%,and 85.82% respectively,and the recycling efficiencies were improved by 9.58%,7.11%,and 6.24% respectively.Furthermore,the abrasion between the mill equipment and the remaining slags was significantly reduced owing to the efficient recovery of larger M-Fe particles.In addition,the using amount of grinding balls was reduced by 0.46 kg when every 1 t steel slag was processed.