I have bauxite powder which contains irregular particles. If I separate out these particles on the basis of sphericity range (how much a particle is in a spherical shape) then what should be the method or techniques? I mean, let say, out of 100gm of bauxite powder, if I select the sphericity range from 0.1-0.5 as the first lot, 0.6-0.7 as the second lot and 0.8-1 as the third lot then which method should be used to get these three lot separately?