MODELING OF PARTICLE STRATIFICATION IN JIGS BY THE DISCRETE ELEMENT METHOD

This paper attempts to review the theories and mathematical models whi ch have been advanced to explain the jigging process. The existing lit erature on mathematical modelling and quantitative analysis of jigging reveal that very little is known about the stratification of particle s in a jig bed. It is realized that a microscopic model is the one tha t is most suited to study stratification in jigs. A new modelling appr oach based on Newtonian mechanics is used to study the stratification behavior of particles in a batch jig. In this approach, the motion of solid particles is treated using the discrete element method (DEM). Si nce in DEM, the motion of the particles is computed from the forces ac ting on them, the effect of the fluid is easily incorporated through t he buoyancy and drag forces. For illustration purposes, a jig bed cons isting of 400 particles of two different densities is simulated. Preli minary results show that the model predicts the stratification of part icles reasonably well. (C) 1998 Elsevier Science Ltd. All rights reser ved.