A comparative study on phyllosilicate and tectosilicate mineral structural properties

Natural minerals are widely used in numerous environmental applications, mainly as sorbents in ion exchange and sorption processes. Minerals, such as zeolites and clays, can be found all over the world, but they are mined containing a variety of different impurities; this prevents their accurate characterization. The present study examines various methods used for the characterization of three common natural silicate minerals, one zeolite (clinoptilolite) and two clays (montmorillonite and vermiculite). Their characterization was performed through a series of analytical measurements so as to gather all the information needed regarding their structural properties. Therefore, 'similar' minerals such as clinoptilolite vs. heulandite and vermiculite vs. hydrobiotite can be distinguished; revealing important properties when comes to their practical application. The methods used in the present study are X-ray powder diffraction (XRD), X-ray fluorescence, Fourier transform infrared (FTIR) spectroscopy, TG/DTG/DTA and N2-porosimetry (BET). An extensive literature review of the natural silicate minerals has been conducted and the relevant results and methods are comparatively reported. The analytical results enabled the distinguish of the examined minerals. XRD, FTIR, TG/DTG/DTA showed that all three minerals have characteristic bands that can be used to easily distinguish from others.