Micromeritics Tristar 3000 (Georgia, USA) instrument, utilizing
N2(g) adsorption technique, was used to determine the surface area
and porosity of vermiculite samples. The specific surface area, calculated
by BET method, and average pore diameter of purified vermiculite
were measured as 3.68m2/g and 30.5 nm, respectively. Elemental analysis
was performed by X-ray Fluorescence instrument (Spectro Xepos)
from Spectro Analytical Instruments GmbH, Germany. The results
showed that the essential components were Si4+, Mg2+, Al3+, Fe3+,
and K+. The mineralogical analysiswas performed by Rigaku Geigerflex
D-Max/B model XRD instrument (Japan) coupled with monochromatic
Cu-Kα radiation (λ = 1.5405 Å), with a scan rate of 2°/min for 2θ between
2 and 50°. XRD results, given in Fig. 1, showthat vermiculite samples
mainly contain and are intermixed with phlogopite, kinoshitalite
and hydrobiotite minerals. It is well-known that vermiculite and mica
often occur in a mixed order of stacking in which an individual crystal
may consist of two or more layer silicates