不同pH值下高密度细泥对煤泥浮选的影响

Effect of High Density Fine Slime on Coal Flotation Behavior at Different pH Values

通过浮选试验研究了不同pH值下高密度细泥对各粒级低密度精煤浮选效果的影响,并结合粒度分析、煤粒表面的Zeta电位对试验结果进行了探讨。浮选试验结果表明,酸性条件下精煤产率最低,中性条件下浮选效果最好,精煤产率最高。激光粒度分析说明,矿浆pH值的降低会使颗粒间凝聚程度增加,高密度细泥更容易罩盖在煤粒表面。zeta电位测量发现,中性环境下,低密度级煤粒和高密度细泥表面均荷负电,二者之间存在静电斥力,在一定程度上阻止了高灰细泥在煤表面的罩盖;当pH值小于低密度级煤粒等电点时,低密度级煤粒表面带正电,而高灰细泥表面荷负电,二者之间存在静电引力,导致高灰细泥在煤表面发生严重罩盖。

The effect of the high density fine slime on coal flotation behavior at different p H values is studied by micro-flotation,which is further discussed combining with particle size and surface Zeta potential analysis of coal particles. The result shows that,the flotation yield of the micro-flotation test under acidic condition is the lowest,and it has the highest yield under neutral condition. The decrease of the p H value of the ore slurry will worsen the particles dispersion, the agglomeration phenomenon between the particles is obvious,and the high density fine coal is easier to cover the surface of the low density coal. In the neutral environment,the surface of the low density coal and the fine slime are negatively charged. When the p H is lower than the isoelectric point of the low density coal,the zeta potential of the low density coal surface is negative,and there is an electrostatic adsorption between the low density coal and the fine coal slime.