低品位难选铁矿转底炉直接还原中试研究

Pilot Study on Direct Reduction of Low Grade Refractory Iron Ore by Rotary Hearth Furnace

采用转底炉直接还原焙烧-磁选方法,对低品位难选铁矿进行了转底炉中试试验研究。混合物料配比是m(原矿):m(焦粉):m(膨润土):m(液体粘结剂)=100:33:4:8,转底炉焙烧温度1250℃~1330℃,还原时间为42 min,含碳球团厚度3层(约60 mm),最终获得的球团平均金属化率83.44%,两段磨矿磁选所得还原铁粉产率39.52%,铁品位94.39%,铁回收率83.34%。对还原铁粉压块,压块密度为4.78 t/m3,可以作为优质的电炉炼钢原料。

The pilot scale test of the low grade refractory iron ore was carried out in a rotary hearth furnace by direct reduction roasting and magnetic separation.The metallized pellets with a average metallization rate of 83.44%could be obtained by the mixed material ratio of raw ores,coke powder,bentonite and liquid binder at the ratio of 100:33:4:8,rotary hearth furnace roasting temperature from 1250℃to 1330℃,reduction time of 42 minutes,and the thickness of carbon-containing pellets of 3 layers(about 60 mm).After the two stages of grinding-magnetic separation,the reduction iron powder could be obtained with yield of 39.52%,TFe grade of 94.39%and iron recovery of 83.34%.The reduction iron powder could be compressed into blocks with the density of 4.78 t/m3,which could be used as a high-quality charge for electric steelmaking.