Study of characteristics of particle distribution on trough surface of spiral separator

In order to explore the pattern of distribution of materials on trough surface of spiral separator, test is made on separation of the coarse-grained coal slime with 9 different size compositions from Daliuta Coal Preparation using the 5LL-Φ600 spiral separator. Then the separated products respectively obtained are analyzed. As evidenced by test result, the ＞0.125 mm material can be effectively separated with the separator; when the material size is smaller than 0.125 mm, it is disadvangeous to its separation due to no distinctive material stratification and zoning effect on trough surface; the material tends to undergo stratification in the radial direction on trough surface with lighter particles in upper layer and heavier particles in lower layer; the material tends to become zonated in the longitudinal direction with the heavier particles on the inside and the lighter particles on the outside; and the separation process is effected according to both density and size. It is noted therefore the size range of the material can exert a great influence on result of material separation; the wider the size range, the greater the size classification effect, making the material more unfavorable for separation according to density; and the narrower the size range, the more suitable the material becomes for separation.