Expanded Vermiculite

General Description:
Vermiculite {(Mg, Fe, Al)3(Al, Si)4O10(OH)2 - 4H2O, Hydrated Magnesium Iron Aluminum Silicate Hydroxide} is an important member of the Montmorillonite/Smectite Group, members of which also belong to the larger general group known as the Clays. Vermiculite is also sometimes placed in the Mica Group, although recent analysis has excluded it from this group. Vermiculite is basically overly hydrated biotite or phlogopite. Natural specimens originated as these minerals and later altered to vermiculite through weathering or hydrothermal processes. Vermiculite typically forms small platy mica like crystals. These crystals contain water in their structures and when heated to above 870C, the water turns into steam causing the crystals to expand rapidly. The volume increase can be 2000 to even 3000%.

Appearance: Flakes or powder

Applications
Vermiculite is very useful for many industrial purposes. It is very lightweight, chemically non-reactive, fire resistant and odorless. Vermiculite can be used to soak up such toxic liquids as fertilizers, herbicides and insecticides. It is this ability that is also being put to good use as a bedding for pets and livestock. In addition, vermiculite can be used in concrete and ceramics as a heat resistant additive.

Important Properties
Vermiculite is usually brown to golden brown, also white, colorless or yellow. Luster is pearly to greasy. Its Crystals are translucent and Crystal System is monoclinic; 2/m. Its Crystal Habits include pseudohexagonal tabular crystals or "books", also found in compact or lamellar masses or microscopic crystals. The Cleavage is perfect in one direction, basal. Fracture is uneven to lamellar. The Hardness is 1.5 (can sometimes leave marks on paper). The Specific Gravity is 2.3 (below average). Its crystals expand to many times their original volume when heated. Best Field Indicators are softness, color, luster and expandability when heated.

Grades

Size Densities Equivalent names/designations
mm in kg/cu m lb/cu ft System A System B
16 5/8 down 56-72 3.5-4.5 NA Premium (6)
8 5/16 down 64-85 4.0-5.0 1 Large (4)
4 5/32 down 72-90 4.5-5.5 2 Medium (3)
2 0.08 down 75-112 4.7-7.0 3 Fine (2)
1 0.04 down 80-144 5.0-9.0 4 Superfine (1)
0.5 0.02 down 90-160 5.6-10.0 5 Micron (0)

In addition to the standard range of vermiculite product above GREAT WALL MINERAL can manufacture vermiculite grades tailored to customers specific requirements.

For more detailed information please contact the expanded vermiculite manufacturer GREAT WALL MINERAL.



Jumbo bags:1 cubic meter, 1.2 metric ton