The Concentration Process Numerical Simulation(CFX) Of Thickener With A Peripheral Feedwell

A large quantity of tailings with low concentration and high moisture was discharged in the mineral process. In the treatment process of the tailing slurry,the study of the characteristics of the tailings material and the laws of the settlement is not deep enough, so that the treatment is always inefficient.The type of flocculants, the optimum dosage and optimum feed concentration were determined based on the analysis of tailings materials and static sedimentation experiments. The yield stress and viscosity can be obtained by the rheology experiments with different concentrations of paste tailings with viscometer. With numerical fitting technique in Matlab software, the relationship between yield stresses, viscosity and volume concentrations can be obtained.Based on ANSYS CFX software, a numerical simulation model of laboratory thickener was established and simulated. It is important to use correct flocs size distribution and density to describe the sedimentation process and mathematics model correctly when a computational fluid dynamics model was used. Because of the sticky of floc, particle size measurement with laser particle size analyzer could affect the normal operation of the laser and stirred system results in the floc fragmentation, affecting the measurement effect. Therefore, The PIV measurement system is constructed to measure the floc size and settling velocity of flocs.The study showed that the simulation results by CFX model with above user defined function and experimental results are basically the same. The CFX simulation showed that the feed slurry can be diluted by overflow water and it is favorable for the solids sedimentation. But the turbulent velocity was higher in the outlet of peripheral feedwell and part of solids enter the overflow zone which makes the water quality lower. A peripheral feedwell with inclined baffle can improve the overflow water quality. According to the experiment results, a large-scale concentrator model was simulated and a numerical model of the large-scale concentrator model proves the numerical model can be used to predict the practical problems of thickener and provide the recommendations for sizing and design of the industrial thickener.