Abstract
To clarify the fundamental mechanism of shape separation for irregular particles, the relationships between the shape and the friction angle of a particle on an inclined plane were investigated by using typical geometric particles (regular polygon and ellipse) and two kinds of irregular particles. The particle shape was evaluated by a shape index φ (Eq. (23)). The results obtained were as follows:
(1) The theoretical relationships between the rolling friction angle αcr and φ for regular polygon particles agree approximately with the theoretical ones for ellipse particles.
(2) Experimental relationships αcr vs. ψ for irregular particles could be estimated by the above theoretical ones.
(3) On the surface of a plate having a larger sliding friction angle αcs, shape separation might be performed more effectively.
(4) The three dimensional shape of a particle could be closely related to the rolling frictional characteristics.
