Particles feel a water pulse u(t) = A w sin(w t) (w = 2 pi f). Each grain relaxes toward the velocity
v* = u(t) - vt (1 - phi)^4.65
vt = sqrt( (4/3) g d (rho_p/rho_w - 1) / Cd )
so dense Mn ore (rho 4.4) settles faster than gangue (rho 2.6) during suction and the bed stratifies. Surface flow carries the light top layer over the weir (tails); heavy grains smaller than the screen aperture sift into the hutch, the rest leave through the bottom gate. Recovery is the heavy fraction reaching the concentrate.