Study on the Dispersion Characteristics of Slurry and Bubble Velocity in a Flotation Column

Flotation column is widely used in coal slime flotation, and the flotation performance of flotation column is affected by many factors. Bubbles and particles in the flotation column were taken as the research object, and the effects of slurry flow rate and apparent gas flow rate, slurry concentration and particle size on slurry dispersion characteristics and bubble velocity distribution were discussed in the paper. The axial dispersion model and residence time distribution (RTD) technique were used to evaluate the slurry dispersion number. The experimental results showed that the slurry dispersion was better when the range of slurry flow rate, apparent gas flow rate, slurry concentration and particle size was 0.007～0.021 m/s, 0.007～0.021 m/s, 1.5～10.89 kg/m³ and 63.22～507.67 mm, respectively. With the increase of apparent gas flow rate, slurry flow rate and particle size, the dispersion number of slurry increased. With the increase of slurry concentration, the viscosity of mixed phase increased and the dispersion number of slurry decreased. The velocity distribution model was used to explore the changes of bubble dispersion and velocity distribution characteristic factors. It was found that the increase of slurry concentration increased the bubble velocity distribution characteristic factor by 35.14%, while the bubble motion dispersion number decreased by 42.06%. The experimental results can provide valuable theoretical insight for the selection of optimum process parameters of flotation column.