(206g) Numerical Study on the Separation Characteristics and Kinematic Behavior of Particles in a Hydrocyclone

During the production process of titanium dioxide by sulfuric acid method, the incomplete reaction produces huge amount of acid hydrolysis residue which contain unreactive ilmenite. It was reported that more than 10 million tons of acid hydrolysis residue have been accumulated without any processing, which resulted in the waste of resources and serious environmental pollution problems. Hydrocyclone were regarded as a method to separate and recover them efficiently. In this work, to improve the classification sharpness, the separation characteristic and kinematic behavior of particles in a 75 mm hydrocyclone was studied by numerical method. The results showed that the particle motion was jointly controlled by the drag force, the pressure gradient force and the centrifugal force. For particles of different sizes, the drag force played a decisive role in the radial direction, the centrifugal force and the pressure gradient force remained about the same. While with the increasing of particle size, the drag force decreased exponentially. As a result, the influence of the centrifugal force and the pressure gradient force was strengthened, manifested as the increasing of the separation efficiency. Among the overflow particles, most particles moved rapidly to the bottom of the vortex finder, entering the inner vortex. Among the underflow particles, with the increasing of particle size, particles entered the outer vortex in a faster rotation speed with a clearer motion trajectory. Besides, it also investigated the influence mechanism of particle density, fluid viscosity, inlet flow rate, particulate arrangement and split ratio on the separation characteristic and the motion behavior of the particle phase.