Physico-chemical and mineralogical characterization

of a Moroccan bentonite (ibourhardaine)

and determination of its nature and its chemical structure


A. Er-ramly*, A. Ider

 Laboratoire de procédés et de l'exploitation des ressources naturelles, l'Environnement et les matériaux,

Département de Chimie Appliquée et Environnement.

L'équipe de développement, la structure et les propriétés des matériaux,
Faculté des Sciences et Techniques de Settat BP 577, Unive
rsité Hassan 1er Maroc

* Corresponding author. E-mail:
Received: 07April 2012; revised version accepted:25 May 2012



     This study concerns the results of Physicochemical and mineralogical characterization of a Moroccan bentonite (bentonite Ibourhardaine) and determination of its nature and its chemical structure. Several techniques were used; in particular X-ray diffraction (XRD), scanning electron microscopy coupled with EDX microanalysis (SEM-EDX), differential thermal and gravimetric analyses (DTA-TGA) and finally infrared Fourier transform (FTIR) and X-ray fluorescence (XRF). The bentonite fine fraction (< 2 µm in size), was characterized by BET method for specific surface area, and a cation- exchange capacity.

     The X-ray diffraction analysis supplemented by gravimetric analysis showed that Ibourhardaine bentonite is  primarily (smectite) (54 wt %) with the presence of feldspar (23 wt%),Quartz (19 wt %) magnetite (3 wt%) and an amorphous iron oxide in the form of scales (1 wt%). It has a cation- exchange capacity of 82 meq/100g and a specific surface area by using surface area analyser and N2 gaz was used as adsorbate under atmosphere of 35 m²/g.the structural formula calculated for bentonite has shown that the montmorillonite has a high charge density and has a rich iron. SEM-EDX, X-ray, chemical analysis and Infrared spectroscopy demonstrated that this montmorillonite contains iron Fe3 + in the octahedral sheet. The origin of the charge sheets is octaedral (Al1.26 Mg0.57), with the montmorillonite character of the bentonite (57%) is present (more than 50% octahedral charge) with a phase rich in iron.

Keywords:  XRD; (DTA-TGA) (SEM-EDX); FTIR; FX; Bentonite; Ibourhardaine; Montmorillonite; Morocco.

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