Abstract

This work reports the experimental analysis of the dispersion characteristics in a three-phase counter-current flotation column. Dispersion characteristic of the slurry phase was strongly dependent on the superficial gas and slurry velocities, slurry concentration, particle size, and surfactant dose. The ranges of superficial gas and slurry velocities, slurry concentration, and particle size were 0.007 − 0.021 m/s, 1.5 − 10.89 kg/m³, and 63.22 − 507.67 µm, respectively. The residence time distribution (RTD) technique was used to estimate the dispersion number based on the axial dispersion model. The results showed that with the increase of superficial gas and slurry velocities and particle size, the dispersion number increases, whereas it decreased with an increase in the slurry concentration. In addition, the velocity distribution model was applied to analyze the dispersion due to bubble motion, and the velocity distribution characteristic factor. The parameters in the velocity distribution model, dispersion due to bubble motion, and velocity distribution characteristic factor were also determined based on the experimental conditions. It was observed that an increase in the slurry concentration significantly increased the velocity distribution characteristic factor by 35.14%, while the dispersion coefficient of the bubble motion decreased by 42.06%. An empirical correlation was developed to predict the dispersion number, dispersion due to bubble motion, and the velocity distribution characteristics factor. The predicted values were in reasonable agreement with proposed correlations within the error range of ± 20%.

摘要

这项工作报告了三相逆流浮选柱中分散特性的实验分析。浆液相的分散特性强烈依赖于表观气体和浆液速度、浆液浓度、粒度和表面活性剂剂量。表观气体和浆液速度、浆液浓度和粒径范围为 0.007 - 0.021 m/s, 1.5 - 10.89 kg/m ³, 和 63.22 − 507.67 µm，分别。使用停留时间分布 (RTD) 技术来估计基于轴向分散模型的分散数。结果表明，随着表观气体和浆液速度和粒径的增加，分散数增加，而分散数随着浆液浓度的增加而减少。此外，应用速度分布模型分析气泡运动引起的弥散，以及速度分布特征因子。速度分布模型中的参数、气泡运动引起的弥散度和速度分布特征因子也是根据实验条件确定的。观察到浆液浓度的增加使速度分布特征因子显着增加了 35。14%，而气泡运动的色散系数下降了42.06%。开发了经验相关性来预测色散数、气泡运动引起的色散和速度分布特征因子。预测值与建议的相关性在 ± 20% 的误差范围内合理一致。