Study On The Dynamics Of Mineralization Process Of Turbulence Controlled Particle Fluidized Bed

In order to solve the problems of high energy consumption,uneven distribution of turbulence and low efficiency of countercurrent mineralization existing in the traditional flotation methods,a turbulence controlled particle fluidized bed(three-phase fluidized bed)flotation column was proposed,which was designed by adding solid particles into the gas-liquid two-phase fluidized bed.In this study,the distribution and variation of bubble and gas holdup in each fluidized region were investigated by the bed pressure drop method and the conductivity probe method respectively,and then the characteristics of bubble surface area flux under various working conditions were clarified.The results show that the existence of turbulence controlled particles in the three-phase fluidized region can effectively improve the bubble stability,reduce the difference of bubble diameter and make the bubble more uniform in the fluidized region.Gas holdup in fluidized bed can be effectively increased by selecting suitable particles and static bed height appropriately.The synergistic effect of water velocity and gas velocity on gas holdup shows that there exists a critical liquid-gas velocity ratio,and the gas holdup increases rapidly when the liquid-gas velocity ratio is less than the critical value.Both theoretical calculation and dynamic characteristics of fluidized bed show that selecting suitable solid particles,the height of static bed,superficial water velocity and gas velocity is a effective way to increase the bubble surface area flux in fluidized bed.The study of fluidized bed dynamics with turbulent controlled particles shows that the gas performance of fluidized bed can be effectively improved by setting appropriate operating parameters,and the optimization effect of flotation column is remarkableThe experimental study on fluidization characteristics of turbulence controlled particle fluidized bed shows that the solid material with small particle size is more favorable to the fluidization of three-phase fluidized bed,while the minimum fluidization velocity of fluidized bed has no direct relationship with the number of particles.The increase of superficial gas velocity is also beneficial to the fluidization of the three-phase fluidized bed,and the minimum fluidization velocity of the fluidized bed decreases linearly with the increase of gas velocity.Both theoretical analysis and the variation law of fluidized bed expansion characteristics prove that the particles with large density can effectively weaken the bed fluctuation and stabilize the flow field during the mineralization process.The study on fluidization characteristics of turbulence controlled particles in fluidized bed shows that the appropriate solid particles can effectively improve the fluidization performance of the fluidized bed,and the appropriate increase of gas velocity can make the three-phase fluidized bed reach the fluidization level at a lower liquid velocity,thus reducing the energy consumption in the flotation process.This study is based on the dimensionless analysis and multiple linear regression analysis,and the standard dimensionless parameter model of flotation column was put forward by model factor analysis,which can effectively predict the gas holdup,fluctuation and expansibility of fluidized bed.A prediction model of bubble diameter was proposed based on the height of the stationary bed which plays an important guiding role in the automatic application of flotation equipment.Flotation experiment results show that the appropriate static bed height,water velocity and gas velocity can improve the flotation column recovery of each coal slime,and the optimum flotation effect is 49.06% of flotation perfect index,72.43% of cleaned coal yield and 9.54% of ash content,respectively,which confirms the optimization effect of flotation flotation environment and fluidization characteristics in flotation flotation process.