某难选褐铁矿直接还原焙烧-磁选工艺研究

Application of Direct Reduction Roasting-Magnetic Separation Process in Recovering Refractory Limonite Ore

对某难选褐铁矿进行了直接还原焙烧-磁选工艺研究。进行了焙烧温度、焙烧时间以及还原剂添加量的条件试验,以及焙烧样品的多种磁选流程对比试验。在原料粒度-2 mm,焙烧温度1 150℃,CaCO3用量为矿量的15%,煤添加量为矿量的25%,盖煤量为球团质量的33%,保温时间2 h,一段磨矿粒度为-0.045 mm粒级占97%,一次粗选场强79 kA/m、两次精选场强45 kA/m时,矿物焙烧金属化率95.24%,铁精矿品位80.61%,回收率88.58%。

Direct reduction roasting-magnetic separation technology was studied to recover a refractory limonite ore. Condition tests on roasting temperature, roasting time and the dosage of reductants were conducted and the results of a variety of magnetic separation processes for concentrating roasted samples were compared. With the granularity of feed ore as -2 mm, roasting temperature of 1 150 ~C, the dosage of coal and CaCO3 as 25% and 15%, respectively, of the total feed, the amount of coating coal as 33% of the pellet weight, the roasting time of 2 h, with the grinding fineness of -0. 045 mm 97%, and the magnetic separation field intensity for roughing and cleaning as 79 kA/m and 45 kA/m, respectively, excellent beneficiation results can be obtained, with the metallization rate of mineral roasting amounting 95.24%, and the iron grade and recovery of iron concentrate reaching 80.61% and 88.58%, respectively.