新型三段式粗颗粒浮选柱内流场数值模拟

Numerical simulation of flow field in a new three-stage coarse particle flotation column

本文对一种新型三段式粗颗粒浮选柱内流场特性进行了研究,结果表明,稳流板的加入可增强粗颗粒浮选柱内流体的湍动能和湍流耗散率,促进气泡和粗颗粒的相互作用以及湍动能、湍流耗散率和液相速度的均匀分布,从而利于矿化气泡的输送。射流管个数的增加使粗颗粒浮选柱内湍动能和湍流耗散率分布趋向于均匀。对称的4个射流管可显著改善流场分布,形成的漩涡促进了气泡与颗粒的相互作用,稳流板使气泡速度分布均匀。浮选柱内湍动能随着上升水量和充气量的增加而增大,稳流板作用明显。上升水量对稳流板上下方区域湍流耗散率的影响呈梯级分布,可实现底部紊流矿化、中部紊流−稳流转变、上部静态流态化浮选的三段式流体环境,利于粗颗粒矿物浮选的回收。

In this paper,the flow field characteristics inside a new three-stage coarse particle flotation column were investigated.The investigation results show that the addition of flow stabilizing plate can enhance the turbulent kinetic energy and turbulent dissipation rate of the fluid in the coarse particle flotation column,promote the interaction between bubbles and coarse particles and the uniform distribution of turbulent kinetic energy,turbulent dissipation rate and liquid phase velocity,thus facilitating the transport of mineralized bubbles.The increase of the jet tube number makes the distribution of turbulent kinetic energy and turbulent dissipation rate in the coarse particle flotation column tend to be uniform.The symmetrical four jet tubes can significantly improve the distribution of the flow field,the vortex formed promotes the interaction between the bubbles and particles,and the stabilizer plate makes the bubble velocity distribution uniform.The turbulence energy in the flotation column increases with the increase of rising water volume and inflation volume,and the effect of the flow stabilizer plate is obvious.The influence of the rising water volume on the turbulent dissipation rate in the area above and below the flow stabilizer plate has a graded distribution,which can realize the three-stage fluid environment of turbulent mineralization at the bottom,turbulence-steady flow transition in the middle,and static fluidization flotation in the upper part,which is conducive to the recovery of coarse-grained minerals by flotation.