Study On The Motion Mechanism Of Fine Particles Based On FLUENT-EDEM In Different Turbulent Environments

The flotation of fine-grained minerals is still a recognized problem in the world.Because of its small size and light weight,the particles will move with the fluid in the fluid,and there is not enough inertia to deviate from the streamline of the fluid,making it difficult to collide with the bubbles.The difficulty in recovering fine-grained minerals has caused a lot of waste of resources.Existing flotation kinetic theory also shows that the particle pulsation velocity and slip velocity will directly affect the collision frequency of particles and bubbles,so the accuracy of the sliding velocity and pulsation velocity in the turbulent environment will directly affect the accuracy of the prediction of the collision frequency model.To carry out research on the movement law of micro-particle solid-liquid two-phase flow in a turbulent environment,and establish the relationship between the characteristics of the turbulent flow field and the pulsation velocity and slip velocity of the micro-particles.In this paper,the study of the motion law of particles with different particle sizes and different densities under different turbulence intensities is simulated by EDEM coupled with FLUENT.It aims to explore the movement mechanism of mineral particles in the mineralization stage of mineral flotation.The specific research contents and conclusions are as follows:1.Study the characteristics of the turbulent flow field excited by a regular grid.The fluid induces an approximately isotropic turbulent flow through the grid,which provides a basis for adding particles to study the movement of particles in different turbulent flow fields.2.Adopt FLUENT-EDEM to simulate liquid-solid two-phase flow,and compare with the experimental data to verify that the appropriate model and setting parameters are selected.3.FLUENT-EDEM was used to simulate the density of 2000kg/m~3,3000 kg/m~3,and 4000 kg/m~3 when the particle size is 74?m.The turbulence intensity is 16%-17%,9%-10%,6%-7%,3%-4%flow characteristics,and processed and analyzed the particle-fluid slip velocity.And the numerical simulation of the particle size of150?m,225?m,and 300?m when the density is 2000 kg/m3,and the turbulence intensity is 16%-17%,9%-10%,6%-7%,3%-4%,The particle-fluid slip velocity is processed and analyzed.It is concluded that the turbulence intensity can not only increase the particle slip velocity,but also the particle velocity pulsation intensity.Increasing the particle inertia(increasing particle density or particle size)under the premise of unchanged turbulence intensity will cause The particle slip velocity continues to increase,and this increasing trend will gradually decrease;at the same time,the particle velocity pulsation will decrease.Moreover,when the intensity of turbulence is higher(about 10%or more),the smaller the space for increasing the particle slip velocity.When the intensity of turbulence is small,the space for increasing the particle slip velocity is larger.Finally,the obtained data are used to fit the prediction formulas of particle slip velocity and particle velocity pulsation.