Effect of particle morphology on coagulation of silica

Ahmad Hassanzadeh*, Esra Tanisali, Behzad Vaziri Hassas, Fırat Karakaş, Mehmet S. Celik

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Citation (Scopus)


Coagulation is basically an aggregation process where particles settle under the influence of interfacial forces with electrostatic forces playing a governing role. Although particle morphology consisting of shape and roughness dictates the physical encounter of two particles, their eventual coagulation is not only influenced by columbic forces but also other interfacial forces such as hydrophobic interaction, which affects the extent of aggregation of particles through increasing the distance of interaction. Roughness is well known to increase the effective contact angle on hydrophobic surfaces and also enhance interfacial forces. In this study, the effect of morphology of particles and particularly roughness on the settling velocity and in turn coagulation tendency was investigated. Batch settling tests (BSTs) of different particle morphologies were investigated as a function of pH. Two different morphologies of silica particles were utilized with the same particle size distribution (PSD) including smooth-spherical and rough-spherical (Etched). Rough particles were prepared by acid etching technique using hydrofluoric (HF) at different time intervals (15-300 sec). Etched samples were identified and quantified by optic profilometry. Settling test results showed that the settling velocity of particles in a suspension of 2% solids in the massive settling region is significantly affected by particle morphology of the suspension. Coagulation results further revealed that aggregation of rough particles is faster than smooth-spherical particles. Coagulation results are elucidated on the basis of particle morphology and its effect on distance of separation through hydrophobic forces.

Original languageEnglish
Title of host publicationIMPC 2016 - 28th International Mineral Processing Congress
PublisherCanadian Institute of Mining, Metallurgy and Petroleum
ISBN (Electronic)9781926872292
Publication statusPublished - 2016
Event28th International Mineral Processing Congress, IMPC 2016 - Quebec City, Canada
Duration: 11 Sept 201615 Sept 2016

Publication series

NameIMPC 2016 - 28th International Mineral Processing Congress


Conference28th International Mineral Processing Congress, IMPC 2016
CityQuebec City

Bibliographical note

Publisher Copyright:
© 2017 TAPPI Press. All rights reserved.


  • Coagulation
  • Hydrophobic Forces
  • Roughness
  • Settling Rate
  • Silica


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