We analyse numerically a density segregation of a monodisperse packed bed of particles with different densities on a forward acting grate. The motion of the particles was simulated using a discrete element method (DEM). The geometry of the grate simulates a pilot-scale furnace for thermal conversion of biomass. The particulate material consisted of spherical particles of which the densities varied by a factor of 2. Segregation was analysed for different grate kinematics meaning that both bar amplitude and frequency, i.e., the bar motion velocity, were subject to change. Based on statistical analysis, we derive mixing and segregation parameters along the coordinate axes, from which a global mixing parameter for the entire packed bed was derived that is dependent on the bar motion. Segregation through density is described by the same type of segregation parameter as in case of the size induced segregation investigated in an earlier study. (C) 2016 Elsevier B.V. All rights reserved.