Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-27T06:21:30.664Z Has data issue: false hasContentIssue false
  • English
  • Français

Textural and structural modifications of saponite from Cerro del Aguila by acid treatment

Published online by Cambridge University Press:  09 July 2018

M. Suárez Barrios ,
C. de Santiago Buey ,
E. García Romero  and
J. M. Martín Pozas
M. Suárez Barrios*
Affiliation:
Area de Cristalografía y Mineralogía, Departamento de Geología, Facultad de Ciencias, Universidad de Salamanca, Plaza de la Merced S/N, E-37008-Salamanca, Spain
C. de Santiago Buey
Affiliation:
Departamento de Cristalografía y Mineralogía, Facultad de Geología, Universidad Complutense de Madrid, Ciudad Universitaria, MadridSpain
E. García Romero
Affiliation:
Departamento de Cristalografía y Mineralogía, Facultad de Geología, Universidad Complutense de Madrid, Ciudad Universitaria, MadridSpain
J. M. Martín Pozas
Affiliation:
Area de Cristalografía y Mineralogía, Departamento de Geología, Facultad de Ciencias, Universidad de Salamanca, Plaza de la Merced S/N, E-37008-Salamanca, Spain
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The physicochemical properties of clays can be modified by acid treatment with inorganic acids. This treatment is usually referred to as ‘acid activation’, because it increases the specific surface area and the number of active sites of the solids. In the present study, the acid activation of saponite from Cerro del Aguila (Madrid, Spain) with HCl solutions was measured. Illite, quartz and small amounts of feldspar were found as impurities in the raw saponite.

Acid treatments were carried out with different concentrations of HCl solutions. The samples obtained were characterized by mineralogical and chemical analyses, XRD, FT-IR spectroscopy, N2 adsorption-desorption isotherms and TEM. The acid attack, under the conditions employed, produced a progressive destruction of the structure of saponite by partial dissolution of the octahedral Mg(II) cations. Amorphous silica coming from the tetrahedral sheet of saponite was generated. The specific surface area of the most intensely treated sample (2.5% for 24 h) was doubled with respect to that of natural saponite. This increase in the surface area is due to the increase in both the external and internal surface areas.

Keywords

bentonitesaponiteacid activationtransmission electron microscopySpain
Type
Research Article
Information
Clay Minerals , Volume 36 , Issue 4 , December 2001 , pp. 483 - 488
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Fahn, R. & Fenderl, K. (1983) Reaction products of organic dye molecules with acid treated montmorillonite. Clay Miner. 18, 447–458.Google Scholar
Kaviratna, H. & Pinnavaia, T.J. (1994) Acid hydrolysis of octahedral Mg2+ sites in 2:1 layered silicates: An assessment of edge attack and gallery access mechanisms. Clays Clay Miner. 42, 717–723.CrossRefGoogle Scholar
Kooli, F. & Jones, W. (1997) Characterization and catalytic properties of a saponite clay modified by acid activation. Clay Miner. 33, 633–643.Google Scholar
Mokaya, R. & Jones, W. (1995) Pillared clays and pillared acid-activated clays: A comparative study of physical, acidic and catalytic propierties. J. Catal. 153, 76–85.Google Scholar
Prieto, O., Vicente, M.A. and Bañares-Muñoz, M.A. (1999) Study of porous solids obtained by acid treatment of a high surface area saponite. J. Porous. Mater. 6, 335–344.CrossRefGoogle Scholar
Santiago Buey de, C., Suárez Barrios, M., García Romero, E., Doval Montoya, M. & Domínguez Díaz, M.C. (1996) Study of the bentonites from the ‘Cerro del Aguila’ (Toledo, Spain). Advances in Clay Minerals. Proc. Spanish-Italian Meeting on Clay Minerals, Granada (Ortega-Huertas, M., López-Galindo, A. & Palomo-Delgado, I., editors).Google Scholar
Santiago Buey de, C., Suárez Barrios, M., García Romero, E., Domínguez Díaz, M.C. & Doval Montoya, M. (1998) Electron microscopic study of the illitesmectite transformation in the bentonites from Cerro del Aguila (Toledo, Spain). Clay Miner. 33, 501–510.Google Scholar
Siddiqui, M.K.H. (1968) Bleaching Earths. Pergamon Press, Oxford.Google Scholar
Srasra, E., Bergaya, F., Vandamme, H. & Ariguib, N.K. (1989) Surface properties of an activated bentonite. Decolorization of rape-seed oils. Appl. Clay Sci. 4, 411–421.CrossRefGoogle Scholar
Suquet, H., Chevalier, S., Marcilly, C. & Barthomeuf, D. (1992) Preparation of porous materials by chemical activation of the Llano vermiculite. Clay Miner. 26, 49–60.Google Scholar
Tessier, D. (1984) Etude de l'organisation des matériaux argileux. Hydratation, gonflement et structuration au cours de la dessiccation et de la réhumectation. The‘se de Docteur en Sciences de l'Univ. Paris VII.Google Scholar
Tessier, D. & Pedro, G. (1987) Mineralogical characterization of 2:1 clays in soils: Importance of the clay texture. Proc. Int. Clay Conf. Denver, 78–84.Google Scholar
Vicente Rodríguez, M.A., Suárez Barrios, M., López González, J.D. & Bañares Muñoz, M.A. (1994) Acid activation of a ferrous saponite (griffithite): Physicochemical characterization and surface area of the products obtained. Clays Clay Miner. 42, 724–730.CrossRefGoogle Scholar
Vicente Rodríguez, M.A., Suárez Barrios, M., Bañares Muñoz, M.A. & López Gonzalez, J.D. (1996) Comparative FT-IR study of the removal of octahedral cations and structural modifications during acid treatment of several silicates. Spectrochim. Acta A, 52, 1685–1694.Google Scholar