Material segregation when handled for a variety of reason many solids flow practitioners quickly identify the potential for fine material to sifting through the matrix of coarse particles as material slides down a pile.indeed sifting segregation is a predominant cause of separation during handling of differently sized particles this mechanism usually result in a radial segregation pattern where fines accumulate near the center of a pile while the coarse material is predominate at the pile edge however severs sifting segregation can cause a top-to-bottom segregation pattern where the fines are beneath the coarse particle this is especially true if inter-particle motion is induced within the material by some external means such as vibration typically particle size differences greater than three to one are enough to produce significant sifting segregation problem