Ultrasonic Bentonite Dispersion

• Bentonite clays, such as sodium bentonite, calcium bentonite and potassium bentonite, are mainly used as additive for drilling fluids, binder, purifier, adsorbent, and as a groundwater barrier.
• Due to strong bonding and van der Waals forces, the dispersibility of bentonite requires intense mixing forces to break the agglomerates uniformly.
• Ultrasonic dispersing is a highly reliable method to produce highly viscous slurries with large amounts of solid concentration. Thereby, ultrasonic excels conventional agitators producing homogeneous slurries of bentonite.

Bentonite Dispersion

Bentonite has manifold applications such as lubricant, thickener or adsorbens. In order to benefit from bentonite’s material characteristics, the bentonite particles/ platelets must be uniformly distributed into a base medium. Bentonite dispersions have a high swelling capacity and can adsorb a high amount of fluid. When dispersed into a liquid, the bentonite dispersion forms a highly thixotropic colloidal suspension or gel. The colloidal properties of bentonite dispersions are highly dependent of the quality of the dispersion. Therefore, ultrasonication is the preferred dispersing technique to obtain high quality bentonite slurries.

Ultrasonic dispersion of bentonite (performed with ultrasonic mixer UIP2000hdT)

Problems

Conventional dipsersion methods often cannot induce the intense shear forces required to prepare a homogeneous slurry of functionalized bentonite. Bentonite’s thixotropy and its extraordinary water binding and swelling capability requires better-than-average dispersing equipment that excels in the handling of korkea viskositeetti slurries and provides enough shear to break the agglomerates.
The viscosity of bentonite dispersion increases with increase in concentration. Conventional mixing equipment is not capable to handle the thick slurries lacking in hajonta ja nesteytys quality.
Due to the insufficient mixing capacity, conventional dispersers must be combined with additional processing steps, e.g. milling.

ratkaisu

High-power ultrasonic equipment offers intense shear forces that break the bonding between bentonite particles easily. Highly viscous bentonite slurries can be homogeneously processed feeding the suspension through an ultrasonic reactor chamber where the particles are deagglomerated ja Hajallaan to a uniform particle size. The intense agitation and shearing assist the particles’ reduction down to the targeted particle size. Powerful ultrasonication delaminates ja exfoliates the bentonite (montmorillonite) resulting in a high particle surface that contributes to an improved swelling ja funcionalization of the bentonite.

Ultrasonic Dispersion of Clays

How it works: Highly intense ultrasonic forces induced in liquids create kavitaatio. Ultrasonic kavitaatio is expressed in pure shear. Thereby, the ultrasonic mixing and dispersing technology is ideal to produce thixotropic suspensions with a very high load of particles.
Due to the intense shearing, ultrasound allows to disperse clays efficiently into slurries. As sonication is carried out as continuous inline process, even slurries of high viscosities such as drilling muds, bitumen emulsions, latex or Maalit.

Hielscher Ultrasonics is your partner when it comes to reliable ultrasonic processing. We offer you the full range of ultrasonic homogenizers – from the Lab-laite to the Teollisuuden ultraäänilaitteet for demanding applications such as Jyrsintä, deagglomeraatio ja hajonta. With clusters of the UIP10000 tai UIP16000, there is virtually no limit in the commercial processing of even very large volume streams, including high viscous, pasty material.