低品位难选铁矿转底炉直接还原中试研究

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1 250℃~1 330℃，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。

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

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 1 250 ℃ to 1 330 ℃, 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.