Effect of Humidity of Atmosphere on the Electrostatic Separation of Coal

Abstract

In order to recover the coal concentrate of low ash content, the electrostatic separation of coal was investigated. The separations with and without heating of feed were performed. It was ascertained that the separation without heating in the room temperature and the normal humidity resulted in an excellent recovery, about 98%, to obtain very low ash coal. From the results it was recognized that a suitable humidity was necessary for the electrostatic separation of coal. The effect of humidity on the electrostatic separation of coal was then studied through the measurements of electric discharge between electrodes, the adsorbed moisture on coal, and the electric charge on coal particles in terms of humidity. From these results, it was made clear that the electrostatic separation was excellent in 40〜80% relative humidity of atmosphere.