Experiments on motion of sediment mixtures in a tumbling mill to study fluvial abrasion

Abstract

Detailed understanding of sediment particles' motion inside a tumbling mill as typical laboratory abrasion setup is needed when laboratory experiments on fluvial abrasion of river sediments with mixtures are planned. The abrasion distance for each particle may be determined through its real distance travelled on the surface of the mill charge only. This distance was found to be less than 50% of the mill circumference for one particle's revolution in this specific laboratory arrangement. The quite current approach to use the product of the number of revolutions and the mill circumference was therefore to be modified. A correction procedure is proposed, which depends on the mill rotational speed, the mill charge and the particle size, relative to the mill diameter. The recommended limits of process parameters that should be used for an abrasion experiment are given. Limitations of this sort of set-up in terms of similarity of particle movement and velocity are also discussed.