Effect of energy consumption on dispersion and recovery of coal slimes in a mechanical flotation cell

Abstract

Dispersion characteristics and flotation recovery of different size coal slimes affected by the impeller stirring speed or effective power in a mechanical flotation cell were investigated. The effective power increased as the impeller stirring speed increased but decreased as the coal slime size increased, and air presented a lower effective power than the coal slimes. The dispersion efficiency increased as the effective power increased but decreased as the coal slime size increased, and air presented a higher dispersion efficiency than the coal slimes. Both flotation recovery and matching degree generally increased as the impeller stirring speed increased, and the flotation recovery began to decrease at the impeller stirring speed of 1400 r/min for 0.25–0.045 mm coal slimes and at 1600 r/min for −0.045 mm coal slimes. Both the flotation recovery and matching degree followed the order −0.045 mm＞0.25–0.045 mm＞0.5–0.25 mm.