低品位铁矿石内配煤球团的回转窑脱水工艺研究

发布时间：2018-08-12 15:35

【摘要】：内配煤球团在进入回转窑还原前通常需要在圆筒中进行干燥,以增强入窑球团的强度。为了获得较高性能的干燥球团,对影响干燥球团性能的主要因素进行了研究。结果表明:(1)湖南某低品位铁矿石(-0.074 mm占95.66%)与某神木煤粉(-0.074 mm占83.47%)在碳铁质量比为0.3,膨润土添加量为1%(占铁矿粉+内配煤+膨润土的质量分数),钠盐添加量为3%(与铁矿粉+内配煤的质量比)的情况下制得粒径为5~8 mm、含水量为11.8%的内配煤球团,在内径(装料部分)为150 mm(转速为2.3 r/min)的回转管中进行脱水,适宜的回转管填充率为30%,升温速率为45℃/min,干燥球团的残余水分为7.8%,对应的干燥球团抗压强度为21.76 N/个、落下强度为5.5次/0.5 m,干燥粉化率为1.52%,群落粉化率为1.57%。(2)以实验室试验结果为依据的干燥球团在煤基回转窑中进行直接还原(温度为960℃、有效还原时间为24 min)工业试验,获得了性能指标更优(落下强度为15.70次/0.5 m,抗压强度为23.37 N/个,烘干粉化率为0.82%)的干燥球团,焙烧球团铁的金属化率达83.10%。(3)焙烧球团在磨矿细度为-0.045 mm占96.15%情况下进行1次湿式弱磁选(磁场强度为180 k A/m),可获得铁品位达80.33%、铁回收率为78.20%的精矿。
[Abstract]:The inner coal pellets usually need to be dried in the cylinder before entering the rotary kiln to enhance the strength of the pellets. In order to obtain high performance dry pellets, the main factors affecting the performance of dry pellets were studied. The results show that: (1) the ratio of low grade iron ore (-0.074 mm, 95.66%) to Shenmu coal powder (-0.074 mm, 83.47%) in Hunan Province is 0.3, bentonite content is 1% (mass fraction of coal bentonite in iron ore powder), sodium salt addition is 3%. Under the condition of mass ratio of coal to coal in iron ore powder, the pellets with a particle size of 5mm and water content of 11.8% were prepared. Dehydration is carried out in a rotary tube with an inner diameter (feeding part) of 150mm (rotating speed 2.3 r/min). The suitable filling ratio of the tube is 30, the heating rate is 45 鈩，

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