In metal mining operations, hydrocyclones are used to separate suspended solids from liquids, for further processing. The thick copper slurry feeds the hydrocyclone, which uses centrifugal movement to sort solids into two pre-determined sizes. The coarse particles (underflow) exit the bottom, continuing for further grinding — while the finer particles (overflow) exit the top, along with most of the fluid. Large mining operations can require multiple hydrocyclones, with each employing up to 12 knife gate valves for feed control of the abrasive media.