Abstract: Aiming at the problems of separation difficulty caused by imperfect separation process and equipment for manganese ore of -8 mm+1 mm， a three-product dense medium hydrocyclone separation and recovery process is proposed. The internal flow field and separation performance of a three-product dense medium hydrocyclone were numerically simulated and experimentally studied by using computational fluid dynamics （CFD） software. The simulation results showed that the flow field of three-product dense medium hydrocyclone is relatively stable in a certain inlet velocity range， and the tangential velocity and axial velocity increase with the increase of inlet velocity. Therefore， properly increasing the inlet velocity is more conducive to the separation of manganese ore. By predicting the density field distribution of dense medium suspension， the flow characteristics of swirling flow field are obtained， which provides a theoretical basis for the optimization of flow field structure. The results of separation test showed that the effective separation of concentrate and gangue can be realized by using the non pressure feeding dense medium beneficiation process， and the separation efficiency is significantly improved. The yield of concentrate of 36.00% was obtained with the condition of the density of the slurry at the overflow port of the secondary cyclone of 2.6 g/cm3 and the pressure of 0.08 MPa. The grade of Mn in the concentrate is 44.58% and the recovery rate is 56.81% with the raw ore grade of 28.25%. This process recover the refractory manganese ore effectively.

Key words: manganese ore separation, three-product dense medium hydrocyclone, numerical simulation