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Structural and Textural Modifications of Palygorskite and Sepiolite Under Acid Treatment

Published online by Cambridge University Press:  28 February 2024

M. Myriam ,
M. Suárez  and
J. M. Martín-Pozas
M. Myriam
Affiliation:
Area de Cristalografía y Mineralogía, Departamento de Geología, Universidad de Salamanca, Plaza de la Merced s/n, Salamanca, 37008, Spain
M. Suárez
Affiliation:
Area de Cristalografía y Mineralogía, Departamento de Geología, Universidad de Salamanca, Plaza de la Merced s/n, Salamanca, 37008, Spain
J. M. Martín-Pozas
Affiliation:
Area de Cristalografía y Mineralogía, Departamento de Geología, Universidad de Salamanca, Plaza de la Merced s/n, Salamanca, 37008, Spain
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Abstract

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Sepiolite from Mara (Zaragoza, Spain) and palygorskite from Attapulgus (Georgia, USA) were activated by treatment at different concentrations with solutions of boiling HCl under reflux conditions. The natural and treated solids were characterized by mineralogical, chemical and textural analyses.

Acid attack resulted in a progressive dissolution of the octahedral layer of these silicates. Silica contents increased and octahedral cations (Al, Mg and Fe) decreased with the intensity of the acid attack. In both cases, fibrous free silica was obtained.

The sepiolite was destroyed more rapidly than palygorskite under the conditions used because of its magnesic composition and the larger size of its structural microchannels. The maximum increase in specific surface area was obtained for sepiolite at 3 N and for palygorskite at 9 N. Cleaning and disaggregation of the particles and the increase in the number of micropores were responsible for this increase in specific surface area.

Keywords

Acid AttackActivation of ClaysFibrous SilicaPalygorskiteSepiolite
Type
Research Article
Information
Clays and Clay Minerals , Volume 46 , Issue 3 , June 1998 , pp. 225 - 231
Copyright
Copyright © 1998, The Clay Minerals Society

References

Abdul-Latif, N. and Weaver, C.h., 1969 Kinetics of acid dissolution of palygorskite and sepiolite Clays Clay Miner 17 169–178 10.1346/CCMN.1969.0170305.CrossRefGoogle Scholar
Bonilla, J.L. López-González, J.D. Ramírez, A. Rodríguez, F. and Valenzuela, C., 1981 Activation of a sepiolite with dilute solutions of HNO3 and subsequent heat treatments: II. Determination of surface acid centres Clay Miner 16 173–179 10.1180/claymin.1981.016.2.05.CrossRefGoogle Scholar
Campelo, J.M. García, A. Luna, D. and Marinas, J.M., 1987 Catalytic activity of natural sepiolites in cyclohexene isomerization Clay Miner 22 233–236 10.1180/claymin.1987.022.2.11.CrossRefGoogle Scholar
Cetisli, H. and Gedikbey, T., 1990 Dissolution kinetics of sepiolite from Eskieser (Turkey) in hydrochloric and nitric acids Clay Miner 25 207–215 10.1180/claymin.1990.025.2.06.CrossRefGoogle Scholar
Corma, A. Mifsud, A. and Pérez, J., 1986 Etude cinetique de l’attaque acide de la sepiolite: Modifications des proprietés texturales Clay Miner 21 69–84 10.1180/claymin.1986.021.1.06.CrossRefGoogle Scholar
Corma, A. Mifsud, A. and Sanz, E., 1987 Influence of the chemical composition and textural characteristic of palygorskite on the acid leaching of octahedral cations Clays Clay Miner 22 225–231 10.1180/claymin.1987.022.2.10.CrossRefGoogle Scholar
Corma, A. Mifsud, A. and Sanz, E., 1990 Kinetics of the acid leaching of palygorskite: Influence of the octahedral sheet composition Clay Miner 25 197–205 10.1180/claymin.1990.025.2.05.CrossRefGoogle Scholar
Corma, A. and Perez-Pariente, J., 1987 Catalytic activity of modified silicates: I. Dehydration of ethanol catalyzed by acidic sepiolite Clay Miner 22 423–433 10.1180/claymin.1987.022.4.06.CrossRefGoogle Scholar
Galán, E. and Espinosa, J., 1978 El caolín en España. Características y ensayos cerámicos Madrid Soc Esp Ceram y Vidrio.Google Scholar
González, L. Ibarra, L.M. Rodríguez, A. Moya, J.J. and Valle, F.J., 1984 Fibrous silica gel obtained from sepiolite by HCl attack Clay Miner 19 93–98 10.1180/claymin.1984.019.1.10.CrossRefGoogle Scholar
González, F. Pesquera, C. Benito, I. Mendiroz, S. and Pajares, J., 1989 Mechanism of acid activation of magnesic palygorskite Clays Clay Miner 37 258–268 10.1346/CCMN.1989.0370309.CrossRefGoogle Scholar
Güven, N., 1992 The coordination of aluminum ions in the palygorskite structure Clays Clay Miner 40 457–461 10.1346/CCMN.1992.0400410.CrossRefGoogle Scholar
Herrero, J. Pajares, J.A. and Blanco, C., 1991 Surface acidity of palygorskite-supported rhodium catalysts Clays Clay Miner 39 651–657 10.1346/CCMN.1991.0390611.CrossRefGoogle Scholar
Martín-Pozas, J.M., 1975 Analisis cuantitativo de fases cristalinas por DRX .Google Scholar
Mendelovici, E., 1973 Infrared study of attapulgite and HCl treated attapulgite Clays Clay Miner 21 115–119 10.1346/CCMN.1973.0210207.CrossRefGoogle Scholar
Pierce, C., 1953 Fine particle measurement Phys Che 57 149–163 10.1021/j150503a005.CrossRefGoogle Scholar
Rives, V., 1991 A computer program for analyzing nitrogen adsorption isotherms on porous solids Adsorption Sci Technol 8 95–104 10.1177/026361749100800204.CrossRefGoogle Scholar
Sing, K.S.W. Everett, D.H. Haul, R.A.W. Moscou, L. Pierotti, R.A. Rouquerol, J. and Siemienewska, T., 1985 Reporting physisorp-tion data for gas/solid systems, with special reference to the determination of surface area Pure Appl Chem 57 603–619 10.1351/pac198557040603.CrossRefGoogle Scholar
Singer, A., 1976 Dissolution of two Australian palygorskites in dilute acid Clays Clay Miner 25 126–130 10.1346/CCMN.1977.0250209.CrossRefGoogle Scholar
Suárez, M. Flores, L.V. Vicente, M.A. and Martín-Pozas, J.M., 1995 Acid activation of a palygorskite with HCl: Development of physico-chemical, textural and surface properties Applied Clay Sci 10 247–258 10.1016/0169-1317(95)00007-Q.Google Scholar
Sugiura, M. Hayashi, H. and Suzuki, T., 1991 Adsorption of ammonia by sepiolite in ambient air Clay Sci 8 87–100.Google Scholar
Vicente, M.A. López-González, J.D. and Bañares, M.A., 1994 Acid activation of a Spanish sepiolite: Physiochemical characterization, free silica content and surface area of products obtained Clay Miner 29 361–367 10.1180/claymin.1994.029.3.07.CrossRefGoogle Scholar