Knowledge-based modeling of dust lifting behind shock waves is a prerequisite for realistic simulation of dust explosions. Mostly numerical simulations of this process focus on dusts consisting of monodisperse particles, while real dusts are polydisperse. This article investigates the effect on the lifting process of the dust being polydisperse with a log-normal distribution of particle sizes. The spatial distribution of the various sizes in the rising layer is studied, and statistical results for the rise, the collision frequency and the particle kinetic energy are compared for polydisperse and monodisperse dusts. It is shown that a layer consisting of polydisperse particles rises significantly faster than a one consisting of monodisperse particles, all other parameters being the same. (c) 2009 Elsevier B.V. All rights reserved.