Dispersion

Opening up bentonite to its primary structure.

Besides genetic parameters and the quality of raw bentonite, the dispersibility of bonding clay is mainly determined by the type and intensity of the Conditioning of bonding clay. Particle agglomerates can generally be dispersed as follows:

  • Compressive stress and/or shear stress between two surfaces
  • Agglomerates bouncing onto a surface or against each other
  • Breakdown caused by the surrounding media in a laminar or turbulent shear zone
  • Breakdown caused by short-term pressure wave ultrasonic treatment
  • Breakdown caused by non-mechanical energy supply

These stress mechanisms are similar to those caused by particle breakdown, however at considerably lower intensity. Bentonite achieves an optimal breakdown of its agglomerates even at low dispersion intensity (corresponds to a soft mold material conditioning); thus it is considered as easily dispersible. In contrast, bentonites which are difficult to disperse require higher dispersion intensity (hard mold material conditioning) in order to achieve adequate mold material properties.

Additional references:
Bentonite sand
Calcium bentonite
Sodium bentonite
Sand conditioning
Sub-conditioning
Western bentonite