MINIMUM RECOVERY ZONE HEIGHT IN FLOTATION COLUMNS FROM PARTICLE-BUBBLE COLLISION ANALYSIS

A particle-bubble collision model is used to investigate the minimum r ecovery zone height, H-r,H-min, required for flotation columns. The cr iterion that is used to define minimum recovery zone height is that he ight which gives unit collision probability. It is shown that H-r,H-mi n is determined by particle and bubble size, gas hold-up and bubble-bu bble interaction. Under typical operating conditions, for flotation of particles <10 mu m in size H-r,H-min is greater than 10 m, but it red uces to less than 1 m for particles >100 mu m.