Influence des particules fines sur la stabilité d'un milieu granulaire
type: Dataset
description: The aim of this work is to understand the effect of very fine particles on the phenomenon of re-agglomeration in the grinding process. Various amount of fine glass beads of 0 to 20 µm (0 to 1% mass concentration) are added to a granular pile of glass beads of 200 to 300 µm rotated in a drum with inner diameter and length of 10 cm. The presence of fine particles shows an ambivalent effect on the stability of the granular heap. We established a stability diagram of the granular medium as a function of fine concentration and quantified the effect of fines combined with other parameters (relative humidity and rotation velocity). The stability of a granular heap in a rotating drum is determined by the measurement of the maximum angle of stability θm. Firstly, we studied the evolution of this angle with different rotation velocities. The experiments indicate that at low fine concentration (< 0:15%), the heap destabilizes through avalanches when the drum rotates, and increasing the fine quantity tends to decrease θm. When the rotation velocity increases, the granular medium transits from intermittent avalanche to continuous flow. In contrast, once the concentration is more than 0:15%, the destabilization of the heap proceeds through a stick-slip phenomenon at the drum wall, and the increase of the fraction of fines tends to increase the stability of the heap. This apparent contradictory behavior is linked to the modification of the destabilization location. In the small concentration regime, the avalanches start at the surface of the heap, and the filling of the interstitial space by the fine particles makes this surface smoother and smoother, thus destabilizing the heap. Besides, the fines induce, through the nucleation of capillary bridges between grains, an increase of the bulk cohesion of the heap. So in the large concentration regime, the heap behaves as a solid body and the destabilization occurs at its bottom. We also studied the influence of relative humidity on th…
identifier: NNT: 2013ECDL0034
issued: 2026-05-05T22:05:14.491619
language: fr
modified: 2026-05-05T22:05:14.491624
contact point: Organization
  fn: CCSD
keyword: angle-davalanche
keyword: avalanche-angle
keyword: broyage
keyword: capillary-condensation
keyword: condensation-capillaire
keyword: friction
keyword: grinding
keyword: infoeu-reposemanticsdoctoralthesis
keyword: mohr-coulomb
keyword: spiotherengineering-sciences-physicsother
keyword: theses
landing page: https://theses.hal.science/tel-00963654

Influence des particules fines sur la stabilité d'un milieu granulaire
type: Distribution
format: HTML
issued: 2026-05-05T22:05:14.517743
modified: 2026-05-05T22:05:14.468360
access URL: https://theses.hal.science/tel-00963654

test_moissonnage_selune
type: Agent