某鲕状赤铁矿流化床燃煤还原焙烧-磁选研究

运用小型循环流化床锅炉,针对铁品位为49.20%、磷质量分数为1.16%的湖北某鲕状赤铁矿进行磁化焙烧-磁选试验研究.试验结果表明,将粒径为106～150 μm的鲕状赤铁矿在700 ℃下焙烧15 min,选取磨矿后粒径在74 μm以下的颗粒质量分数为85%的焙烧矿物,运用湿式磁选管在139.22 kA/m的磁场强度下对筛选后的焙烧矿物进行磁选抛尾,可以获得铁品位为55.12%、全铁回收率为70.11%、磷质量分数为0.67%的铁精矿.研究表明,运用循环流化床局部还原性气氛高速磁化焙烧铁矿石是可行的,运用该磁化焙烧-磁选工艺流程可以达到一定的提铁降磷效果.

Reduction roasting and magnetic separation of oolitic hematite ore by coal combustion in fluidized bed

Using the small circulating fluidized bed boiler, the experimental study was conducted on the Hubei oolitic hematite with iron grade of 49.20%, and phosphorus mass fraction of 1.16% by means of magnetic roasting and separation. The oolitic hematite ore with the size of 106 ～150 μm roasted at 700 ℃ for 15 minutes. Then the roasted ore which accounted for 85% of the mass fraction with the grinding fineness of less than 74 μm after grinding was chosen. The wet magnetic separation tube was used to conduct magnetic separation of roasting minerals with the magnetic field intensity of 139.22 kA/m. The iron concentration with iron grade of 55.12%, total iron recovery rate of 70.11% and phosphorus mass fraction of 0.67% was achieved. Using circulating fluidized bed to improve the quality of iron ore in local reducing atmosphere is feasible, and using the magnetic roasting-magnetic separation process can achieve a certain effect of iron increase and phosphorous reduction.