(414h) Segregation of Particles in Electrostatic Environments Where Particles Are Subject to Rebound

Understanding segregation is critical to being able to produce quality products. Material can segregate by fines sifting through a matrix of coarse particles. Air currents may entrain fine particles causing segregation in systems where gas velocities in the free board space are great enough to entrain particles. Differences in frictional characteristics of particles can cause two particles to slide past each other and separate as they form a pile. However, segregation can also occur as particles with different coefficients of restitution rebound on a pile or other surfaces. Likewise, electrostatic effects can induce segregation of two materials with different electrical permittivity values and charge dissipation behaviors. These types of segregation occur in the freeboard space above a pile, but are influenced by particle interaction with the pile surface. In this paper we examine the driving forces for these two effects separately as well as instances when they exist with each other and other mechanisms. We have developed models to describe these effects and have measured the segregation of particle conditions where electrostatic charge is present. We have developed methods to quantify these two causes of segregation when they act together, and when they interact with more traditional segregation mechanisms. This paper presents a method of using segregation test data coupled with segregation models to quantify the type of segregation in a system on a component-by-component basis.