Study on fluidization characteristic of fluidized-bed flotation based on multi factor

•The effects of various factors on fluidization characteristic were investigated.•The mean and standard deviation of pressure drop is affected by various factors.•The pressure fluctuation is attributed to bubble behavior.•The response surface method based on BBD is used to analyze the data.•The mathematical model of correlation coefficient is established. Fluidized bed flotation involves three phases of gas, liquid and solid, which can be used for the separation of coarse minerals. In this study, a two-dimensional gas–liquid-solid fluidized bed was developed to explore the fluidization characteristics of fluidized bed flotation. The effects of water velocity, air velocity, frother dosage and particle size (Ql, Qg, ρn, Dp) on the average pressure drop (–ΔP) and standard deviation (σΔP) were investigated. As the water velocity increases, the pressure drop initially increases, subsequently decreases and eventually remains constant. Increasing the air velocity will enhance the resistance of the bed to the water flow, resulting in a reduction in the water velocity required by peak pressure drop. Furthermore, the pressure drop is observed to decrease due to an increase in air velocity after reaching complete fluidization. Increasing the particle size has the opposite effect, while variations in frother dosage only influence the peak pressure drop. According to the bubble behavior, the influence of different conditions on the pressure drop fluctuation was analyzed. Increasing the water velocity, the frother dosage and the particle size contribute to a reduction in pressure drop fluctuation, whereas an increase in air velocity has the opposite effect. When the water velocity exceeds 1.2 L/min and the frother dosage exceeds 80 g/t, the pressure drop fluctuation is basically unchanged. Finally, the response surface methodology was used to analyze the interaction among the variables, and a mathematical model of the correlation coefficient was established to predict effects.