Simulation And Effect Evaluation Of Solid-liquid Mixing Process Of Copper Anode Mud In Vertical Kettle

The vertical reactor of copper anode mud is the main equipment for the pressurized copper removal process.However,in the real practical production,due to its closed characteristics of the vertical reactor structure and the complexity of the fluid mixing process,its structural optimization mainly dependent on the empirical or semi-empirical correlation method,and usually couldn't reach the desired mixing effect.In this study,based on the computational fluid dynamics(CFD)technique,using the standard k-? turbulence model,Euler-Euler multiphase flow model and multiple reference flame(MRF)model to establish the simulation model of the stirring and solid-liquid two-phase flow process in the 25 m3 vertical reactor of copper anode mud.Conclusions of the numerical simulation are as follows:(1)The numerical simulation results of stirring power at different rotational speeds has been studied,compared with the empirical formula,the result shows that the mathematical model can fit well with the empirical formula and could be applied in stirring simulation.(2)The effects of stirring speed,blade installation angle,blade distance and baffle height on the comprehensive performance of vertical kettle were investigated by the single factor variable research,the result shows that under the stirring speed of 80 r·min-1,all solid particles in suspended are uniform and can be mixed well,there is no significant concentration difference in the axial direction.With the increase of the inclination angle,the axial vorticity height and the range of the high-speed area were both increased,which can stimulate the solid particles flow to the low concentration area,and the appropriate blade installation angle was 45°.Increasing the blade distance can increase the uniform distribution of the axial solid phase,and the appropriate blade distance was 1.615 m,and increase the baffle height can promote the distribution of the copper anode mud in the reactor.However,continually increase the baffle height would inhibit the float of the solid phase copper anode mud.(3)Using the orthogonal design method to optimize the stirring speed and the structural parameters,and select the stirring speed,the blade installation angle,the blade distance and the damping baffle height as factors to evaluate the solid volume section concentration of vertical reactor.The result shows that the influence of each factor on the solid phase distribution of copper anode mud can be ranged as follows: blade installation angle>stirringspeed> baffle height> blade distance.(4)The optimum stirring-process parameters obtained by orthogonal analysis were determined as follows: the stirring speed was 100 r·min-1,the blade installation angle was 45°,the blade distance was 1.615 m and the baffle height was 2 m,and compared with the actual production conditions,the solid volume section concentration of the reactor has increased by13%.The optimization conditions would produce obvious vortex at the vertical fluid of the vertical reactor,the axial velocity gradient was obvious,and the copper anode mud particles were distributed well in the whole axial.(5)10 combinations of copper anode mud solid-liquid stirring process were selected for principal component analysis,and carried out by the comprehensive and objective evaluation.The six evaluation indexes(the solid volume section concentration of vertical reactor,turbulent kinetic energy of the surface Z1,and Z2,mixing energy per volume,stirring power and mixing time at the monitoring point)were transformed into two comprehensive indexes,which reduced the subjective weight error of the index,and the results show that the best structural parameter condition in the orthogonal analysis method is the highest score,so the principal component analysis method can effectively evaluate the stirring effect.