浮选柱内矿浆分散特性与气泡速度分布规律研究

Study on the Dispersion Characteristics of Slurry and Bubble Velocity in a Flotation Column

浮选柱被广泛应用于煤泥浮选中,而浮选柱的浮选性能受多因素的影响。试验以浮选柱中气泡、颗粒为研究对象,探讨矿浆表观流速及表观气体流速、矿浆浓度、颗粒粒径对矿浆分散特性及气泡速度分布的影响。利用轴向分散模型和停留时间分布(RTD)技术评估矿浆分散数。试验结果表明,矿浆表观流速与表观气体流速、矿浆浓度和颗粒粒径的范围分别为0.007~0.021 m/s、.007~0.021 m/s、1.5~10.89 kg/m^(3)、63.22~507.67 mm时矿浆分散较好。随着表观气体流速、矿浆表观流速及颗粒粒径的增加,矿浆分散数增加,而随着矿浆浓度的增加,混合相黏度增加,矿浆分散数减少。利用速度分布模型探究气泡分散及速度分布特征因子变化,研究发现矿浆浓度的增加使气泡速度分布特征因子增加了35.14%,而气泡运动分散数下降了42.06%。试验结果可以为浮选柱最佳工艺参数选择提供有价值的理论参考。

Flotation column is widely used in coal slime flotation,and the flotation performance of flotation column is affected by many factors.Bubbles and particles in the flotation column were taken as the research object,and the effects of slurry flow rate and apparent gas flow rate,slurry concentration and particle size on slurry dispersion characteristics and bubble velocity distribution were discussed in the paper.The axial dispersion model and residence time distribution(RTD)technique were used to evaluate the slurry dispersion number.The experimental results showed that the slurry dispersion was better when the range of slurry flow rate,apparent gas flow rate,slurry concentration and particle size was 0.007~0.021 m/s,0.007~0.021 m/s,1.5~10.89 kg/m^(3) and 63.22~507.67 mm,respectively.With the increase of apparent gas flow rate,slurry flow rate and particle size,the dispersion number of slurry increased.With the increase of slurry concentration,the viscosity of mixed phase increased and the dispersion number of slurry decreased.The velocity distribution model was used to explore the changes of bubble dispersion and velocity distribution characteristic factors.It was found that the increase of slurry concentration increased the bubble velocity distribution characteristic factor by 35.14%,while the bubble motion dispersion number decreased by 42.06%.The experimental results can provide valuable theoretical insight for the selection of optimum process parameters of flotation column.