Abstract: In order to improve the classification accuracy of FX500 hydrocyclone in tongshankou copper mine and reduce fine particles in underflow， the influence of structure parameters and operation parameters on the separation performance of hydrocyclone was systematically investigated by means of numerical simulation method. The results indicated that: ①Fine particles in underflow and coarse particles in overflow could be decreased as a whole through increasing the inlet velocity and reducing the concentration of ore feeding. ②By increasing the height of column segment and the cone angle， fine particles in underflow were further reduced. ③In addition， fine particles were further washed from underflow and reduced their misplacement in underflow via increasing the upper taper angle of grit mouth. ④The results of on-site experiments verified that the -75 μm particles in underflow of the optimized hydrocyclone decreased by 1.78 percents compared with that of the original hydrocyclone. These results would provide technical supports for optimizing and reforming the hydrocyclone of tongshankou copper mine.

Key words: Hydrocyclone, Numerical simulation, Separation performance, Structure parameters, Operation parameters