Effect of Interaction Between Clay Particles and Fe3+ Ions on Colloidal Properties of Kaolinite Suspensions

Kunsong Ma and Alain C. Pierre
University of Alberta, Edmonton, Canada

Abstract: Fine kaolinite suspensions were mixed with unaged or aged FeCl3 in this experiment. The interaction between clay particles and Fe3+ hydrolysis products was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The proportion of Fe adsorbed was measured and the electrical charge on the clay particles was determined by electrophoresis. The effect of this interaction on flocculation of clay suspensions was investigated in a series of sedimentation tests. The Fe3+ ions acted as counterions when their concentration was low and when unaged FeCl3 solution was used. Otherwise, their hydrolysis complexes acted as a bonding agent between kaolinite particles. The dispersion-flocculation behavior of kaolinite suspensions was found to be in agreement with the theory of Derjaguin, Landau, Verwey and Overbeek (DLVO), as the sedimentation behavior could be predicted from the data of zeta potentials (ζ).

Key Words: Colloid • Electron Microscopy • Flocculation • Iron • Kaolinite • Sedimentation • Zeta Potential

Clays and Clay Minerals; October 1997 v. 45; no. 5; p. 733-744; DOI: 10.1346/CCMN.1997.0450512
© 1997, The Clay Minerals Society
Clay Minerals Society (www.clays.org)