1. Brief introduction:
The mineralogy name of vermiculite is from Latin, with the meaning of “wormlike” and “worm trail”. Vermiculite is a kind of hydrous iron magnesium aluminum silicate mineral, and it is bending like the leech, so it is called “Zhishi” in Chinese. It is formed by biotite (flogopite) by supergene weathering or hydrothermal alteration. Its chemical composition is （Mg、Fe、AL） 3[（Si、AL）4O10（OH）2]·4H2O, but often changes. Vermiculite is monoclinic system, and plate shaped. Color: brown, cinnamon or bronze. Oily luster. Hardness:1~1.5, density : 2.4~2.7g/cm3. There are two kinds of shape: coarse and fine. The coarse ones are transformed by biotite (flogopite) and keep the characteristics of mica flake and scale; the fine ones like earth, and it is difficult to distinguish for mixed with other clay minerals. After roasted on the temperature of 800-1000℃ for 0.5-1 minute, the volume of vermiculite expands rapidly by 8-15 times, some up to 30 times. The average unit weight of expanded vermiculite is 100~130Kg/m3. The expanded vermiculite has tiny air buffer, so it has good thermal insulation property.
2. Chemical composition and specification:
1) Composition of golden vermiculite

Component	SiO2	Al2O3	MgO	CaO	Ph	Fe2O3	Other
Content	41%	18%	21%	0.8%	8-1%	3.5%	< 8%

Specification produced:

Specification	2#	3#	4#	5#
granularity	7-12mm	3.5-7mm	1-3.5mm	0.3-1mm

2)  Composition of silver-white vermiculite:

composition	SiO2	AL2O3	MgO	CaO	FeO	Fe2O3	TiO2
Content	43.2	12.68	24.23	0.96	1.54	4.06	1.33
composition	K2O	P2O5	H2O	Na2O	MnO	TiO	Loss on ignition
Content	5.95	0.08	3	1.6	0.043	5.097	6.50

Specification:

Specification	2#	3#	4#	5#	6#
granularity	4-8mm	2-4mm	1-2mm	0.3-1mm	0.25-0.71mm、0.3-0.6mm

Besides the above common specification, we can produce other ones according to the customers’requirement. 
3. Application and functions:
After roasted, vermiculite has the performance of light unit weight, cold and thermal insulation and sound absorption. Vermiculite is widely used in building, electric power, petroleum, metallurgy, textile, transportation, horticulture, automobile, aircraft manufacturing, agriculture, food and other fields. In building industry, it is used as thermal insulation material, sound absorption material and coating. In agriculture, it can improve soil, and is used as fertilizer carrier material, the carrier of animal feed, deodorant, animal medicine, pesticide and other materials, and can be used as insecticide, bactericide, sanitizer, organic compound synthetic agent, good intermedium for root, stem and leaf of vegetables and other rare plants. Vermiculite felt can absorb the radioactive elements, and it can treat some waste water polluted by radioactive elements