Bentonite Powder


A rock composed essentially of a crystalline clay-like mineral formed by devitrification and the accompanying chemical alteration of a glassy igneous material, usually a tuff or volcanic ash.

Smectite refers to a family of non-metallic clays primarily composed of hydrated sodium calcium aluminum silicate. Common names for smectite include montmorillonite or sodium montmorillonite (“sodium bentonite” or “Wyoming bentonite”) and swelling bentonite (“Western bentonite”).

Types of Bentonite:

  1. Natural Calcium Bentonite or Calcium Montmorillonite
  2. Natural Sodium Bentonite or Sodium Montmorillonite
  3. Sodium Activated Bentonites or Sodium Activated Montmorillonites

Bentonite minerals occur as lenses or seams containing up to 50% moisture. They are rocklike in nature and usually extracted by opencast mining (quarrying).

Natural sodium bentonite as the name suggests occurs with sodium as the predominant exchange cation. Sodium bentonites are characterized by high swelling, high liquid limit, and high thermal durability.

The vast majority of the montmorillonites occurring in abundance worldwide are of the calcium type and referred to as calcium bentonites.

Calcium bentonites are often characterized by much lower swelling and liquid limit values compared to natural sodium bentonite.

Sodium activated bentonites are produced by the substitution of calcium ions by sodium ions. This transformation can be achieved by the addition of a soluble sodium salt to calcium bentonite.

PreRish Tri Produces all 3 types of Bentonite (Industrial Grade) and export all around.

Chemical Formula:  Al2O34SiO2H2O

Chemical Name:  Naturally occurring hydrated luminium silicate

Chemical Properties:

Commercial Grade:  SiO2= 61.3 and Al2O3= 19.8

Food Grade:  Si02 = 58-61, Ca0= 2.0-2.5, Al203=21-22, Mg0= 3-4, Na20= 3.7-4.2, As= 5 ppm max., and Pb= 40 ppm max.

Physical Properties:

Numerous particle size options are available in the lower micron area with a mean particle size of 2.5 to 4.0 microns

Typical Applications:

Used as a foundry sand, paints, fuller’s earth, drilling mud, bleaching clay, filtering agents, water impedance, inks, additive to ceramic materials, and iron ore pelletizing

Pharmaceuticals, beverage, food, cosmetics, and personal care products (Suspending agent, gallant, and binder)

Bentonite possesses thixotropic properties and deposits a thin waterproofing film on the walls of the boreholes & thus renders permeable formations impermeable.

Both natural & synthetic Bentonite is used in the preparation of drilling muds. It is mainly used as circulation mud in the rotary system of drilling for oil. The main purpose of Bentonite is to lubricate & cool the rotary cutting bits, carry away rock cutting fragments & to act as a seal against the escape of gas from the borehole & to improve & prevent the hole from blowing out. Another function of such Bentonite based fluids is to condition the wall of the drill hole to prevent caving.


  • Uncompacted Density (lbs./cu.ft.): 47.5
  • Compacted Bulk Density (lbs./ft3): 37 to 56
  • Specific Gravity: 2.6
  • Surface Area (m2/cc): 0.09 to 1.8
  • Solubility In Water: none
  • pH: 8.5 to 10.5
  • Nominal Color: light cream