Synonyms: Montmorillonite  
Molecular Formula: Al2O3.4(SiO2). H2O
EINECS: 215-108-5  
Molecular weight: 360.31
CAS No: 1302-78-9

Bentonite that used in foundry, metallurgy, well drilling slurry, food, oil, agriculture, chemical industry, environmental protection, zoology construction, ecological construction, building, paper making, textile, printing & dyeing, ceramic, medicine, cosmetic, machine, etc.

Specification:
Description: Calcium based Bentonite
Major Function: Viscosity Agent
Testing specification: Per API spec 13A
600 rpm reading: 30 min
Yield Point / Plastic Viscosity ratio: 3 max
Filtrate volume, ml 15 max
Residue ( 75 micron wt % ): 4.0 max
Moisture, wt %: 10 max

Bentonite is a high swelling clay mineral whose name was derived from the location of the first commercial deposits mined at Fort Benton, Wyoming U. S. A. Mineralogically, bentonite mainly consists of montmorillonite in combination with various mineral impurities such as feldspars, calcite, silica, etc. Montmorillonite belongs to the smectite group of clays which also include similar behaving minerals such as beidellite, saponite and hectorite.

Geologically bentonites are mainly of volcanic origin, The majority of commercial deposits were formed by the hydrolysis or metamorphism of volcanic rock or ash and are almostly found in everywhere in world.

The structure of montmorillonite is fundamentally a three layer structure with an octahedral aluminium hydroxyl sheet sandwiched between two layers of silicon- oxygen tetrahedra. However, the aluminium atoms are partially replaced by the substitution of either magnesium or iron atoms, thereby creating a charge deficiency within the unit structure. This results in a small negative charge on the basal plane of silica tetrahedra which is balanced by absorption of exchangeable cations between adjacent platelets. In natural montmorillonite, these cations are usually calcium, sodium or magnesium according to the formations of bentonite.

A: Foundary (HS 25081000 Bentonite of Lithium /sodium/ calcium)
B: Metallurgy (metallurgy pellet binder) HS 25081000
C: Drilling Mud ( API& OCMA ) HS 25081000
D: Bleaching earth (acid actived and natural ) HS 25084000.