【摘要】：內(nèi)配煤球團在進入回轉(zhuǎn)窯還原前通常需要在圓筒中進行干燥,以增強入窯球團的強度。為了獲得較高性能的干燥球團,對影響干燥球團性能的主要因素進行了研究。結(jié)果表明:(1)湖南某低品位鐵礦石(-0.074 mm占95.66%)與某神木煤粉(-0.074 mm占83.47%)在碳鐵質(zhì)量比為0.3,膨潤土添加量為1%(占鐵礦粉+內(nèi)配煤+膨潤土的質(zhì)量分數(shù)),鈉鹽添加量為3%(與鐵礦粉+內(nèi)配煤的質(zhì)量比)的情況下制得粒徑為5~8 mm、含水量為11.8%的內(nèi)配煤球團,在內(nèi)徑(裝料部分)為150 mm(轉(zhuǎn)速為2.3 r/min)的回轉(zhuǎn)管中進行脫水,適宜的回轉(zhuǎn)管填充率為30%,升溫速率為45℃/min,干燥球團的殘余水分為7.8%,對應的干燥球團抗壓強度為21.76 N/個、落下強度為5.5次/0.5 m,干燥粉化率為1.52%,群落粉化率為1.57%。(2)以實驗室試驗結(jié)果為依據(jù)的干燥球團在煤基回轉(zhuǎn)窯中進行直接還原(溫度為960℃、有效還原時間為24 min)工業(yè)試驗,獲得了性能指標更優(yōu)(落下強度為15.70次/0.5 m,抗壓強度為23.37 N/個,烘干粉化率為0.82%)的干燥球團,焙燒球團鐵的金屬化率達83.10%。(3)焙燒球團在磨礦細度為-0.045 mm占96.15%情況下進行1次濕式弱磁選(磁場強度為180 k A/m),可獲得鐵品位達80.33%、鐵回收率為78.20%的精礦。
[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，

本文編號：2179494