The concentration of about 25% to 30% of the pulp to the ore groove, gravity to the bed, ore particle swarm in bed gounei by water flushing and bed surface vibration and loose, layered, layered on the lower mineral particles in different sizes of water flow dynamic pressure and bed friction effect under motion along different directions. The upper light mineral particles in the larger hydraulic push, more inclined downward movement along the bed surface to remove, this side is called the tailings side. In bed at the bottom of the heavy mineral particles directly in the bed surface differential push downward to the transmission end opposite and discharge, called concentrate end, so, mineral particles according to their different density and particle size and motion along different directions, and from feed chute began along the diagonal fanned out, orderly along the edge of the bed surface discharge, discharging line is very long, can be a variety of different quality of product: concentrate, concentrate, middlings and tailings accurate estate.