能量输入对煤泥浮选过程的影响

摘要

为研究煤泥浮选指标与能量输入的关系,针对细粒级为主导的难选煤泥,建立浮选能量输入测试系统,设计在浮选机轴转速分别为1 500,1 800和2 100 r/min时的浮选速度试验,并对不同浮选能量输入条件下的产品进行粒度分析、密度分析和扫描电镜分析.研究结果表明:随着浮选的进行,煤泥的可浮性越来越差,单位精煤可燃体回收率上浮所需要的能量越来越大；当转速为1 500 r/min,精煤灰分含量(质量分数)为13.27％,可燃体回收率为73.35％时,需消耗能量0.18 W;在相同的精煤灰分含量下,当转速为2 100 r/min时,精煤可燃体回收率为81.01％时需消耗能量0.73 W;在低转速下单位能耗所获取的精煤可燃体回收率比高转速下的高,但在相同浮选时间内,高转速下能获得更高的精煤可燃体回收率;在相同条件下,增加浮选过程能量输入能够提高精煤质量或可燃体回收率;在低能量输入条件下,损失的精煤主要是粗粒级的煤岩连生体,粗颗粒连生体和煤岩解离较好的微细粒煤粒需在高能量输入条件才能回收,但同时伴随着异质细泥对精煤的污染.%To investigate the relationship between energy input and coal flotation indicators, some flotation experiments were carried out for fine-grained level as the leading refractory fine coal. Energy input test system of flotation was established and flotation rate tests were studied when the flotation machine shaft speeds were 1 500, 1 800 and 2 100 r/min, respectively. The characteristics of flotation products were analyzed by SEM, size analysis and density analysis under different energy input conditions. The results show that as the process of flotation, floatability of coal slime becomes worse, energy needed by per unit combustible recovery of floating slime increases. At 1 500 r/min of flotation machine shaft speed, the clean coal combustible recovery and ash are 73.35% and 13.27% respectively when energy input is 0.18 W. At the same value of clean coal ash, the clean coal combustible recovery is only 81.01% when energy input is 0.73 W. The recovery of clean coal combustion obtained by unit energy consumption at low speed is higher than that at high speed. However, within the same flotation time higher clean coal combustion recovery can be obtained under high speed condition. Under the same indicator conditions, the quality or the combustion recovery of clean coal can improve with the increase of energy input in flotation process. Loss of coal with low energy input is mainly coarse mineral intergrowth. Coarse particle intergrowth and micro-fine coal particles when rock and coal dissociate can well be recovered with high energy input, but at the same time pollution of heterogeneous fine mud is accompanied on clean coal.