15～5mm酒钢镜铁矿石回转窑焙烧结圈可能性研究

为了开发利用酒钢镜铁山-15 mm的粉状镜铁矿石,在完成对试样和还原煤化学成分、软熔性能分析的基础上,对回转窑磁化焙烧工艺窑壁结圈可能性进行了研究。结果表明:试验原料及各阶段产物的软化温度均在1 100℃以上,当回转窑内温度严格控制在镜铁矿适宜的还原温度850~900℃时,回转窑内物料不会发生软熔和液化;15~5 mm的小块矿采用直径为(0.45~0.65)m×9 m燃气变径回转窑处理,在哈密烟煤用量为2%、焙烧温度为850~900℃、窑内停留时间为2.5 h、填充率为10%、焙烧产物水淬冷却后磨矿细度为-0.074 mm占80%、弱磁选磁场强度为100 k A/m的情况下,可得到铁品位为55.00%、回收率为83.00%的铁精矿,且回转窑内壁360 h未见结圈现象;科学合理的窑型、稳定合理的热制度、适宜的入窑粒度,对减少酒钢镜铁山镜铁矿石回转窑磁化焙烧结圈现象的产生十分有效。

Study on the Ringing Possibility of Specularite Particles Ranging from 5 to 15 mm in Rotary Kiln in Jiusteel

In order to exploit and utilize the powdery specularite at -15 mm in Jingtie Mountain of Jiusteel，the ringing possibility during magnetizing and roasting process in rotary kiln was studied based on the analysis of chemical component and softening melting performance of the ore and the reducing coal.The results showed that when the reduction temperature was strictly controlled at range of 850 ℃ to 900 ℃，the softening phenomenon of the ore did not happen，since the softening and melting temperature of the ore and the stage products is at 1 100 ℃ or above.The ore particles ranging from 15 mm to 5 mm are roasted by gas variable diameter kiln with the size from 0.45 m×9 m to 0.65 m×9 m.Under the condition of carbon powder content of 2.0％，roasting temperature at 850～900 ℃ for 2.5 h，charge ratio at 10％，grinding fineness of 80％ -0.074 mm and low intensity magnetic separation field intensity of 100 kA/m，iron concentrate with iron grade of 55% and the recovery of 83% was received，and the ringing phenomenon did not appear in 360 h.Scientific and rational kiln type，stable and reasonable thermal system，and appropriate particle size，can effectively reduce the ringing formation during magnetizing and roasting process of specularite in the rotary kiln in Jingtie Mountain，Jiusteel.