The bubble size produced in a pilot HydroFloat® cell and its effects on flotation

Unlike a traditional mechanical flotation cell, Eriez's HydroFloat (R) is a fluidized-bed flotation device that can recover much coarser and less liberated particles. This is a new flotation machine where the effects of parameters such as bubble size are yet to be established. To address this problem, JKMRC has built a pilot HydroFloat (R) rig which it deployed to a copper-gold plant in New South Wales, Australia. Tests were performed at a range of operating conditions and bubble size images were collected and analysed using a novel newly created bubble size measurement method. In conventional flotation, a finer bubble size increases flotation rates because it increases the probability of bubble-particle collision and attachment. In this pilot HydroFloat (R) test program, however, flotation performance was optimal at an intermediate bubble size. Using the comprehensive test program data, the operating parameters that significantly affect bubble size were established, and an empirical model to predict bubble size was developed.