Effect of particle size on the relative motion between particles and bubbles

Particle size plays a critical role in flotation. Experimental research on the effect of particle size on the relative motion between mineral particles and bubbles is far more inadequate. In this work, an experimental system is developed to track all particles and extra the parameters. Different sizes of coal particles are used to observe the evolution of the particle trajectory and velocity in the approaching process. The particle trajectory can be divided into two parts, and a bubble will affect the motion of the particle once the particle enters the near part. The distance between the turning point of the particle trajectory and the bubble center increases as the initial settling position expands outward, and the distance for coarse particles is shorter than that for fine particles. The distance to the bubble center when the decrease in the particle velocity reaches 10% is regarded as the boundary of the resistance layer, and the distance for coarse particles is longer than that for fine particles. The particle collision velocity is the final output of the resistance layer. The collision velocity increases as the collision angle increases, and the collision velocity of coarse particles is greater than that of fine particles.