Study On The Influence Of The Structure Of Large-scale Slurry Mixing Tank On The Concentration Distribution Of Pulp

Large-scale slurry mixing tank in the beneficiation of the flotation process to adjust the pulp and pharmaceuticals quickly and evenly mixed for the flotation to create good conditions,is the flotation process necessary mixing equipment.The mixing effect is not only the mixing of the impeller closely,but also with the working environment of the mixing impeller,both the type of fluid medium,the mixing tank and accessories and so on.At present,there are many researches on the effect of impeller on the stirring effect,but there are few researches on the shape and installation of the baffle attachment.The vertical baffle stirring tank has been used as a classic mixing device,while the study of special baffle structures such as tilting baffles is relatively few.The computational fluid dynamics(CFD)theory can be used to obtain detailed information on the macroscopic flow and microscopic turbulence characteristics in the stirred tank.In this paper,the flow field in the stirred tank is simulated by the multi-reference coordinate system(MRF)method in CFD finite element method.The multi-phase flow is obtained from the bucket shape structure,installation method,Field analysis to improve the shear performance of the impeller,to avoid stirring the eddy current,to promote the pulp particles are fully mixed to improve the flow field distribution.The results show that the fluid around the impeller will form two swirling vortices during the stirring process,which will promote the whole circulation of the slurry,the mixing of the impeller around the impeller and the impulses of the impeller.The ratio of the ideal mixing zone(concentration 58%-62%)was the highest when the front inclined baffle was stirred,and when the angle of inclination was 45°and the ideal mixing area ratio of 88.48%,to achieve the best mixing effect.Under the same conditions of the size of the stirring tank and the concentration of the slurry,the ratio of the ideal mixing zone(58%~62%)of the slurry is 30-35r/min,and the optimum mixing effect is achieved.The ideal pulp concentration increases with the increase of the viscosity of the slurry.When the viscosity is 0.015~0.020kg·s/m2,the ideal pulp concentration decreases slightly with the increase of the pulp viscosity.