无烟煤颗粒表面低温氧化过程研究

Low-temperature oxidation process of anthracite particle surface

煤的表面性质是决定细粒煤浮选难易程度的重要因素之一.采用Quanta 250(FEI)环境扫描电子显微镜系统及Bruker QUANTAX400-10电制冷能谱仪对氧化不同时间的煤粒表面进行SEM面分布研究.结果表明:随着氧化时间的增加,煤粒表面孔洞增加,且沿着孔洞出现裂隙,煤表面成灰元素(Si,Al)含量增加,图像平均灰度值随时间成负对数变化,碳含量减小的趋势以及氧含量增加的趋势都逐步缓和;煤粒表面Zeta电位均为负值,且逐渐减小,减小趋势逐步缓和;煤粒表面平均灰度值与Zeta电位的变化趋势相同.

Surface property of coal is one of important factors determining coal flotability. The Quanta 250 （FED environmental scanning electron microscope and Bruker QUANTAX400-10 electric refrigeration spectrometer were used to analyze SEM surface distribution of coal with different oxidation time. The results show that with the increasing of oxidation time, the number of hole on the surface of coal increases and the crack appears along the holes, the ash elements （Si, A1） contents on the surface of the coal inerease. The average gray scale values analysis shows that the decreasing trend of carbon content and oxygen content becomes slow. The Zeta potential of coal is negative and decreases gradually with the oxidation time increasing. The decreasing trend of the Zeta potential also becomes slow. As oxidation time increases, the average gray values and Zeta potential on the surface of coal particles have the similar variation.