Effect of prewetting time on different size fraction flotation performances of low rank coal

Abstract

In this paper, X-ray photoelectron spectroscopy, scanning electron microscopy and induction time measurements were used to indicate the surface properties of low rank coal particle surfaces. The flotation responses of different size fractions of low rank coal treated by different prewetting times were investigated. For the greater mass force of coarse particle size fraction (0.500-0.250 mm), it may need more attachment time to firmly adhere to the bubble during the induction time measurement. In other words, a short prewetting time has a positive effect on the flotation of coarse low rank coal particles. After a long time prewetting process, the prewetted low rank coal particles with low ash content should be much easier to contact with the collector than the prewetted low rank coal particles with middle ash content although a slight entrainment phenomenon may occur in fine size fraction. [Received: March 13, 2017; Accepted: October 17, 2017]