Effect of particle shape on particle-bubble interaction behavior: A computational study using discrete element method

Abstract

A three-dimensional Discrete Element Method (DEM) simulation model of particle-bubble interaction behavior based on particle-bubble mechanics theory was developed, and six kinds of irregular shape particle models were designed. The interaction behavior of spherical and irregular-shaped coal particles with the particle size of 0.1 mm and densities of − 1.3, 1.4–1.5, + 1.7 g/cm3 and a fixed bubble in quiescent water was simulated. The simulation results show that the interaction between spherical and irregular shape particles with the bubble can be divided into five stages: free settling, flow around the bubble surface, sliding with a liquid film, film rupture & three-phase contact line (TPCL) formation, sliding with a TPCL. Irregular shape particles have a larger critical collision angle and capture probability than spherical particles. The critical induction time of irregular particles is smaller than that of spherical particles. Irregular particles with edges and corners can promote the thinning and rupture of the liquid film between bubble and particle，thereby reducing the induction time and increasing the capture probability.