Why does montmorillonite clay swell more than kaolinite clay?
Montmorillonites expand considerably more than other clays due to water penetrating the interlayer molecular spaces and concomitant adsorption. The presence of sodium as the predominant exchangeable cation can result in the clay swelling to several times its original volume.
Why is the specific surface area of kaolinite less than montmorillonite?
Isomorphous substitution is negligible in kaolinite but extensive in montmorillonite; thus kaolinite has much lower charge and cation exchange capacity than montmorillonite. Kaolinite particles tend to be larger than montmorillonite, which gives montmorillonite higher surface area per unit weight than kaolinite.
Is montmorillonite clay the same as bentonite?
Montmorillonite clays and Bentonite clays are one and the same thing. All types of Bentonite clays are grouped together under the Montmorillonite or Smectite group of clays. The clay is named after Montmorillon (France) where it was first discovered.
Why is kaolinite not expanding?
Kaolinite, because it does not absorb water, does not expand when it comes in contact with water. Thus, kaolinite is the preferred type of clay for the ceramic industry.
Why does kaolinite not expand?
What is the chemical structure of kaolinite and montmorillonite?
Kaolinite and montmorillonite are clay minerals. These minerals have their chemical structures as sheets stacked on each other in different ratios. 1. Overview and Key Difference
What type of mineral is kaolinite?
Kaolinite is a type of clay mineral having the chemical composition Al 2 SiO 2 O 5 (OH) 4. It is a group of industrial minerals that occurs as a layered silicate mineral with one tetrahedral sheet of silica that is linked through oxygen atoms to another octahedral sheet of alumina.
Does montmorillonite adsorption of toxic metals?
The adsorption of toxic metals, viz., As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Ni, Zn, etc., has been studied predominantly. Montmorillonite and its modified forms have much higher metal adsorption capacity compared to that of kaolinite as well as modified-kaolinite.
What type of mineral is montmorillonite?
Montmorillonite is a type of clay mineral that has the general formula (Na,Ca) 0.33 (Al,Mg) 2 (Si 4 O 10 ) (OH) 2 .nH 2 O. This mineral belongs to the group of phyllosilicates. The crystal system of this material is monoclinic, and the appearance can be described as white, pale pink to red. The fracture of this mineral is uneven.