Naked Science Forum

General Science => General Science => Topic started by: lyner on 11/01/2009 09:46:04

Title: what is 'vermiculite'?
Post by: lyner on 11/01/2009 09:46:04

They use it in horticulture and as insulation. What's it made of?

Title: what is 'vermiculite'?
Post by: Chemistry4me on 11/01/2009 09:51:51

Quote

Vermiculite is a 2:1 clay, meaning it has 2 tetrahedral sheets for every one octahedral sheet. It is a limited expansion clay with a medium shrink-swell capacity. Vermiculite has a high cation exchange capacity at 100-150 meq/100g. Vermiculite clays are weathered micas in which the K+ ions between the molecular sheets are replaced by Mg2+ and Fe2+ cations.

http://en.wikipedia.org/wiki/Vermiculite

Title: what is 'vermiculite'?
Post by: Chemistry4me on 11/01/2009 09:53:49

TYPICAL CHEMICAL ANALYSIS
Element Percent by Weight
SiO2     38-46
AL2O3    10-16
MgO      16-35
CaO      1-5
K2O      1-6
Fe2O3    6-13
TiO2     1-3
H2O      8-16
Other    0.2-1.2

Typical Chemical Formula: (Mg,Ca,K,Fe11)3(Si,AL,Fe111)4O10(OH)2O4H2O

There is even a website about it: http://www.vermiculite.net/

Title: what is 'vermiculite'?
Post by: Andrew K Fletcher on 11/01/2009 18:09:17

makes some nice lightweight fluffy concrete when mixed with 1 part cement 5 parts vermiculite. Used to pack around my log burner which is an insert type

Title: what is 'vermiculite'?
Post by: lyner on 11/01/2009 21:50:18

Cheers for the info chaps.