入选原煤中小于0.5毫米级一般占入选原煤的20%左右,随着采煤机械化程度的提高,煤尘量还有增加的趋势。这些煤尘随着原煤一起进入重选设备。由于重选法对煤的有效分选粒度下限只能达到0.5 Less than 0.5 mm of the selected raw coal generally accounts for about 20% of the selected raw coal, with the increase of coal mining mechanization, there is an increasing trend of coal dust. These coal dusts enter the re-election equipment along with the raw coal. Due to the re-election method of effective separation of coal particle size lower limit can only reach 0.5