Discrete particle simulation of solid separation in a jigging device

This paper presents a numerical study of solid separation in a jigging device, which is a high yield and high recovery gravity separation device widely used in ore processing. The mathematical model adopted is a combination of computational fluid dynamics (CFD) for the liquid flow and discrete element method (DEM) for particle motion. The motion of individual particles is 3 dimensional (3D) and the flow of continuous liquid is 2 dimensional (2D), considering the bed thickness is only 1/3rd of the bed width, and one CFD computational cell is used through the thickness. Periodic boundary conditions are applied on the front and rear walls to emulate a bed of larger thickness using a relatively small number of particles. Stratification is heavily dependent on fluid motion through the jig. The study explores 5 different pulsation profiles. The profiles used are - sinusoidal, triangle, sawtooth-backward, sawtooth-forward, and trapezoidal. The initial packing conditions consist of a binary-density particle system where the light particles and heavy particles, have respective densities of 2540 and 4630 kg/m(3). There are 1130 particles each 1 cm in diameter. As an initial comparison, all simulations are conducted using a fixed peak-peak amplitude and pulsation period. Their relative performances are compared in terms of solid flow patterns, separation kinetics, energy, and mean particle position. The underlying mechanisms are explained in terms of particle-fluid interaction force. These quantitative comparisons demonstrate significant differences in the segregation rate and energy used for various pulsation profiles. (C) 2013 Elsevier B.V. All rights reserved.