Abstract: In order to explore the feasibility of concentration and size of particles on bubble movement and merging behaviors in flotation system, the anthracite is selected as the object of study to explore the bubble merging behaviors under different conditions by using a single-bubble behavior observation system.As revealed by test result, with increase of concentration, the surface tension of solution and bubble breakaway diameter tend to gradually drop with yet a slow downward tendency; yet with the increase of particle size, they show no signs of obvious change; the bubble motion velocity is observed to be reduced with increase of particle size and concentration, causing, as a result, the reduction of number of collision and bouncing of bubbles with liquid surface.