Rare earths are important national strategic resources, but there is a lack of analytical studies on the application of stirring equipment in the leaching process of rare earth. In order to reveal the dynamic law of rare earth ion concentration in the stirred tank with time, the influence of the stirred tank geometry on the fluid flow and the evolution of the free liquid level in the stirred leaching process is analyzed. The newly developed volume fraction algorithm is used to improve the DEM-VOF model, solve the problem of adding the mass transfer kinetic model in the stirred tank, and realize the simulation of the mass transfer process in the rare earth stirring and leaching process. The effects of four stirred tank geometries, namely, flat bottom with baffle, elliptical bottom with baffle, flat bottom without baffle and elliptical bottom without baffle, on the leaching process were investigated. The results show that the leaching of rare earth particles in the stirred tank with baffle is better, the elliptical bottom is more favorable for the leaching reaction of rare earth particles, and the baffle significantly affects the evolution of the free liquid level and requires more power consumption. This study can provide theorizing reference for the design and optimization of operating conditions for rare earth leaching in stirred tanks.
 

Stirred tank, rare earth leaching, multiphase flow, DEM-VOF, free surface