Modeling the size–density partition surface of dense-medium separators

Extension of particle stratification model to incorporate particle size effects

“…4 and 5 respectively show the partition surfaces generated from the stratification model at relative cut heights of 0.2, 0.4, 0.6 and 0.8 for both batch as well as continuous operations. The calculated partition surfaces are similar to what are found in literature (Scott and Napier-Munn, 1992;Venkoba Rao et al, 2003;Venkoba Rao, 2004, 2005 with the added advantage in this case of depicting their profiles at various cut heights of the stratified bed from one simulation. It can be seen that the by-pass fractions in a continuous operation, which depict the recovery of very fine particles to the sink stream, are much lesser to that found in batch operation, for any specified cut height.…”

“…Recently, Xia et al (2007) have proposed a computation fluid dynamics (CFD) based approach to model segregation of particles in the jig bed, wherein the fluid motion is calculated by Navier-Stokes equation and the motion of solid particles is accounted by the Lagrangian frame through the action of forces imposed by the fluid and gravity. The purpose of the present paper is to extend stratification model proposed by Tavares and King (1999) and King (2001) to incorporate the effect of particle size into the earlier formulation so that the integration of size effect with this model produces partition surfaces that are similar to those found in literature (Klima and Luckie, 1989;Scott and NapierMunn, 1992;Venkoba Rao et al, 2003;Venkoba Rao, 2004, 2005. Partition surfaces also suggest the nature of segregation of particles at different cut heights of the stratified bed from their profiles and thus help in deciding the cut height of separation for a targeted product.…”

“…Particle separation in gravity concentrators is influenced by particle size as well as particle density (Klima and Luckie, 1989;Scott and Napier-Munn, 1992;Tavares, 1999;Venkoba Rao et al, 2003;Venkoba Rao, 2004, 2005Xia et al 2007) and these attribute effects on the overall separation can be characterized in terms of bivariate partition function. A bivariate partition function represents the recovery of feed particles of specified size as well as density to one of the product streams and more commonly to the sink stream and thus explains the efficiency of particle separation with respect to the bivariate attributes namely size and density.…”

“…A noteworthy point of the bivariate partition function is that it shows positive and reverse classification of particle sizes depending on whether the particle density is above or below that of pivot density irrespective of the particle size. Several generic functions have been proposed to represent this partition function (Klima and Luckie, 1989;Scott and Napier-Munn, 1992;Venkoba Rao et al, 2003;Venkoba Rao, 2004, 2005. The bivariate partition function is important from the plant operation standpoint as it decides the efficiency of separation of particles in both size and density attributes and hence decides the product quality.…”

Sink–float density separation of post-consumer plastics for feedstock recycling

“…Moreover, in a cylindrical centrifugal force separator (hereinafter referred to as CFS) [2,7,9,10,29], the input material stream is directly fed into the vortex without passing the supplying pump, the measurement, and control equipment. This advantage helps prevent plugging and abrasion.…”