Numerical Simulation Of Bubble Flotation In Ore Pulp

Abstract:The quantity and quality in the mineral flotation are directly influenced by the changing of the size, geometric shape and the velocity of flotation bubbles moving upward in the ore pulp suspension fluid in the froth flotation. Therefore, it is of great significance for improving the production process, product yield and quality to do the research of the flotation bubble motion law in the pulp.On the basis of the overview of the research progress, fundamental theory and simulation progress of the gas-liquid two phase flow and bubble, the physical and mathematical model for single froth bubble are built and related initial boundary conditions are determined in this thesis. Volume of fluid (VOF) method that can capture the free interface is applied to track the movement interface of bubbles, the numerical simulation study of flotation bubbles is carried out based on Fluent6.3platform, and the law of deformation, rising velocity and trajectories of gas bubbles are analysed and summarized.The process of air bubble movement in the pulp is simulated in the condition of no particle attached. The simulation results show that the bubble transverse deformation and sloshing amplitude in vertical direction in the process of its moving upward is becoming larger with greater bubble initial diameter. The bubbles with medium size have gentle deformation with small degree of deformation, big buoyancy lift and strong fluid flow disturbance resistance ability, which have better capacity to carry mineral particles and effectively improve the quantity and quality in the pulp density with practical mineral flotation. The bubble with larger initial velocity which is bad for bubble deformation will be produced by the excessive stirring degree. The optimal size of flotation bubble is different for different ore pulp densities, the degree of the deformation, rising velocity and best flotation bubble size range are smaller with larger pulp densities.The process of mineralized bubble motion with particle attached in the pulp is simulated and the results show that the more particles attached in the unit surface area of bubble, the smaller the deformation degree and rising rate. The calculation results that without regard to shedding ore particle of recycled minerals mass show that the recycled mineral mass is increasing first and reducing after with the increasing mineral particle quantity attached in the unit surface area of bubble. The recycled mineral mass with different sizes of mineralized bubble are compared and analysed, the gotten conclusion is that the recycled mineral mass with bubbles of medium size are greater than other sizes bubbles, therefore, the best size of bubbles in flotation is the bubbles with medium size.31figures,9tables,84references.