Bentonite is an abundant, versatile mineral found in many regions around the world for various industrial applications such as foundry sand, iron ore pelletisation, drilling muds…

Commercial bentonite (sodium montmorillonite) has been very successfully exploited as a basic drilling fluid additives. Its main functions are to viscosify the mud and to reduce fluid loss to the ground.

Problems with Civil Engineering and Drilling bentonite quality, and quality control methods have consistently been observed in the recents years.

There is a large demand to bring lower grade clays into API specifications, or to significantly boost bentonite performances to cope with increasing demand for premium high yield grades.




SNF under the commercial name FLOBENT offers synthetic powder polymers varying in anionic charge and molecular weight to extend the yield of many bentonite grades.


FLOBENT selection

Depending on source, bentonite quality is determined mainly by four parameters :

  • content of materials other than montmorillonite (other clay minerals, mica, feldspar, calsite, quartz…)
  • type of counterion(s) present on the montmorillonite platelets.
  • size, shape and charge of the montmorillonite platelets.
  • presence or absence of small amounts of extending polymers (in the order of 0.025 - 1.0 %)


Laboratory pilot tests are required to determine FLOBENT suitable grade and concentration depending on required performances.

Civil Engineering and drilling grade bentonites are usually tested according to API specifications :

  • API 13B - recommended practices for field testing water based drilling fluids.
  • API 13A - Specification for drilling fluids materials.


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