test_moissonnage_selune
type: Agent

Filtration de silices précipitées: mise en évidence des relations entre propriétés macroscopiques et échelles locales dans les dépôts
type: Distribution
access URL: https://theses.hal.science/tel-00691605
format: HTML
issued: 2026-05-20T17:09:42.961963
modified: 2026-05-20T17:09:42.852758

Filtration de silices précipitées: mise en évidence des relations entre propriétés macroscopiques et échelles locales dans les dépôts
type: Dataset
contact point: Organization
  fn: CCSD
keyword: permeabilite-hydraulique
keyword: silice-precipitee
keyword: aggregate
keyword: diffusion-de-rayons-x-aux-petits-angles-saxs
keyword: precipitated-silica
keyword: hydraulic-permeability
keyword: organisation-multiechelle
keyword: filtration
keyword: small-angle-scattering-saxs
keyword: theses
keyword: modelisation
keyword: multilevel-organization
keyword: agregat
keyword: modelling
keyword: infoeu-reposemanticsdoctoralthesis
keyword: spigprocengineering-sciences-physicschemical-and-process-engineering
landing page: https://theses.hal.science/tel-00691605
description: The production process of precipitated silica used as reinforcing fillersincludes a filtration step carried out to collect silica agglomerates in the synthesized silica dispersion and then to eliminate salts and impurities beforedrying. The purpose of this study is to correlate the multilevel structure ofsilica agglomerates to the mechanical and hydrodynamic properties of filter cakes with or without a washing step. For that, we have chosen different reinforcing silicas which differ from the way the synthesis is conducted and performed the filtration at several operating pressures. The structural, mechanical and hydrodynamic properties of filter cakes were investigated by small angle scattering, osmotic compression and filtration and washing experiments. It appears that for each system two characteristic quantities : the maximum diameter of aggregates and the percolation threshold corresponding to the formation of a network that begins to resist to compression, are correlated to the hydraulic permeability of filter cakes. Moreover, we show that the calculated permeability using a Brinkman model is in quite reasonable agreement with experimental data. Finally, we demonstrate that the elimination of salts and impurities in filter cakes during the washing step affects neither the local organization of filter cakes nor the permeability.
issued: 2026-05-20T17:09:42.885641
language: fr
modified: 2026-05-20T17:09:42.885647