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Vermiculite
 1. Character and structure
Its chemical formula is (Mg,Ca)0.7(Mg,Fe,Al)6.0〔(Al,Si)8.0〕(OH48H2O).
Vermiculite can be divided into raw vermiculite and swell vermiculite according to its phases. According to its colours we can divide it into golden,silvery and milky-white vermiculite.
The volume of raw vermiculite can expand 8-20 times through roasting baking at high temperature.After expanding its specific gravity is 130-180kg/m3.At that same time it has good property of resisting cold or heat.
2.The chemical composition
| composition |
SiO2 |
Al2O3 |
MgO |
Fe2O3 |
CaO |
PH |
H2O |
| content（%） |
37-42 |
9-17 |
11-23 |
5-18 |
0.5-0.8 |
8-11 |
<1 |
3.Main specifications and technical index
(1)Raw vermiculite
| specifications |
No.2 |
No.3 |
No.4 |
No.5 |
| size（mm） |
5-7 |
3-5 |
1-3 |
<1 |
(2)Swell vermiculite
| level |
relax specific gravity |
absorbency（%）） |
impurity（kg/m3） |
| 1 |
130 |
480 |
<1 |
| 2 |
160 |
450 |
<1 |
| 3 |
180 |
420 |
<1 |
4. Main use Vermiculite is used in construction as lightweight materials or fireproof and anti-heating materials.It can also used in metallurgy farming、foresting、 marine fishing 、gardening and other fields.
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