浮选三相流中气泡运动特性的数值模拟

Numerical simulation of flotation bubble motion in a three-phase inner suspension fluid

为获取浮选气泡在矿浆中的运动规律及三相流中浮选气泡的最佳尺寸,运用欧拉模型模拟不同初始直径的气泡在不同密度矿浆中的运动过程.结果表明：在给定的初始条件下,同一浓度的矿浆中,单个浮选气泡所能捕获的矿物量以直径4mm的气泡最多,气泡尺寸增大或减小后,其矿物捕获量都有所减少.当矿浆中固相质量分数在20%~40%之间变化时,矿物捕获量最多的气泡尺寸变化不大,并且随着矿浆中固相质量分数的增大,单个气泡的捕获量增大,矿物粒子回收率增加.在实际生产中,直径为3.5~4 mm的中等大小气泡在运动过程中变形程度小,气泡水平偏移及浮升速度适中,对矿物粒子的捕获率及运载能力和浮升能力较强,有利于提高浮选产量和质量.

To find the motion law and optimum size of floatation bubbles in a three-phase flow,the Eulerian model is used to simulate the motion process of bubbles with different initial diameters in pulps of different concentrations. The simulation results show that under the given initial condition,in the pulp with a certain concentration,bubbles of 4 mm catch the most mine grains; bubbles of any size above or below 4 mm cannot capture mine grains as many as those of 4 mm. When the pulp concentration is in the range of 20%-40%,the size of bubbles that capture the most mine grains does not change much. As the pulp concentration increases,the amount captured by a single bubble increases,so does the recovery rate of mine grains. In real production,bubbles of 3. 5-4 mm have small deformation,moderate horizontal shift and lifting speed,and strong ability of capturing and carrying mine grains and lifting,which are benefit for improving the quality and quantity of floatation production.