Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-05T12:21:59.724Z Has data issue: false hasContentIssue false
  • English
  • Français

Charges on the surfaces of two chlorites

Published online by Cambridge University Press:  09 July 2018

Angela A. Jones
Angela A. Jones*
Affiliation:
Department of Soil Science, University of Reading, Reading, Berks RG1 5AQ, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

Two chlorites, sheridanite and clinochlore, have been examined to determine their surface charge characteristics. In order to increase their surface area and to produce a measurable surface charge, the chlorites were treated with 10−3m, 10−2m, and 10−1m HCl in 10−2m MgCl2 solutions. These treatments are shown not to alter the crystallinity of the chlorites and to produce a small pH-dependent negative charge which is not directly related to the total surface area. The clinochlore, (Si6.13Al1.84)(Al1.53FeIII0.53FeII0.18Mg9.52)O20(OH)16, is more readily attacked by the acids than the sheridanite, (Si5.43Al2.55)(Al2.90FeII0.05Mg8.86)O20(OH)16, and also produces material with greater surface area and pH-dependent, negative, surface charge. It is concluded that: (i) isomorphous substitutions in the lattice are not reflected in a permanent surface charge; (ii) the observed surface charge arises not only at the edges of the particles but also at points where the chlorite is predisposed to attack by acids; (iii) in the chlorite-acid system used, anions—probably mainly silicate—block positively charged sites.

Résumé

Résumé

Les caractéristiques des charges superficielles de deux chlorites, la shéridanite et le clinochlore, ont été déterminées. En vue d'accroître leurs surfaces spécifiques et de produire une charge superficielle mesurable, les chlorites ont été traitées par des solutions 10−2m en MgCl2 et 10−3m ou 10−2m ou 10−1m en HCl. On montre que ces traitements n'altèrent pas la cristallinité des chlorites et produisent une faible charge négative dépendant du pH qui n'est pas directement liée à la surface spécifique totale. Le clinochlore (Si6.13Al1.84)(Al1.53FeIII0.53FeII0.18Mg9.52)O20(OH)16, est plus rapidement attaqué par les acides que la shéridanite (Si5.43Al2.55)(Al2.90FeII0.05Mg8.86) O20(OH)16 et produit également un matériel à plus grande surface spécifique et une plus grande charge superficielle, négative, dépendant du pH. On en déduit: (i) la substitution isomorphique du réseau ne se reflète pas dans la charge superficielle permanente; (ii) la charge superficielle observée n'apparaît pas seulement au bord des particules, mais aussi à des points où la chlorite est prédisposée à êre attaquée par des acides; (iii) des anions—probablement des silicates—bloquent des sites chargés positivement dans les système chloriteacide utilisé.

Kurzreferat

Kurzreferat

Zwei Chlorite, Sheridanit und Klinochlor wurden zur Bestimmung ihrer Oberflächenladungsverhältnisse untersucht. Zur Oberflächenvergrößerung und um eine meßbare Oberflächenladung zu erhalten, wurden die Chlorite mit 10−3, 10−2 und 10−1m HCl in 10−2m MgCl2 Lösungen behandelt. Diese Behandlungen bewirkten keine Veränderung in der Kristallinität der Chlorite und erzeugten eine geringe pH-abhängige Ladung, welche in keinem direkten Bezug zur Gesamtoberfläche steht. Der Klinochlor (Si6.13Al1.84)(Al1.53FeIII0.53FeII0.18Mg9.52) O20(OH)16 wird durch die Säuren etwas leichter angegriffen als der Sheridanit (Si5.43Al2.55) (Al2.90FeII0.05Mg8.86)O20(OH)16 und liefert deshalb Material mit größerer Oberfläche und pH-abhängiger negativer Oberflächenladung. Es wird der Schluß gezogen, daß: (a) isomorpher Ersatz im Gitter nicht durch eine permanente Oberflächenladung wiedergegeben wird, (b) die beobachtete Oberflächenladung nicht nur an den Eckpositionen der Teilchen lokalisiert ist, sondern auch dan den gegenüber Säureangriffen empfindlichen Stellen des Chlorits, (c) in dem verwendeten Chlorit-Säure System Anionen—wahrscheinlich hauptsächlich Silicat—positiv geladene Positionen besetzt halten.

Resumen

Resumen

Dos cloritas, sheridonita y clinocloro, han sido examinadas para determinar sus caracteristicas de carga superficial. Al objecto de aumentat su superficie especifica y producir una carga superficial medible, las cloritas fueron tratadas con soluciones de Cl2Mg 10−2m en ClH 10−3m, 10−2m y 10−1m. Se ha demostrado que estos tratamientos no alteran la cristalinidad de las cloritas y producen una pequeña carga negativa dependiente del pH, que no está relacionada directamente con la superficie total. El clinocloro, (Si6.13Al1.84)(Al1.53FeIII0.53FeII0.18Mg9.52) O20(OH)16, es más fácilmente atacado por los ácidos que la sheridonita, (Si5.43Al2.55) (Al2.90FeII2.90Mg8.86)O20(OH)16, y dá lugar a un material con una mayor superficie especifica y una carga superficial negativa y dependiente del pH. Se concluye que: (i) las sustituciones isomórficas en la red se reflejan en una carga superficial permanente; (ii) la carga superficial observada proviene, no sólo de los bordes de las partículas sino también de los puntos donde la clorita está predispuesta al ataque con ácidos; (iii) en el sistema cloritaácido usado, los anionesprobablemente silicatos principalmentebloquean los puntos cargados positivamente.

Type
Research Article
Information
Clay Minerals , Volume 16 , Issue 4 , December 1981 , pp. 347 - 359
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1981

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

Barnhisel, R.I. (1977) Chlorites and hydroxy interlayered vermiculite and smectite. Pp. 331–356 in: Minerals in Soil Environments (Dixon, J. B. & Weed, S. B., editors). Soil Science Society of America, Madison, Wisconsin, U.S.A. Google Scholar
Brindley, G.W. (1961) Chlorite minerals. Pp. 242-296 in: The X-ray Identification and Crystal Structures of Clay Minerals (Brown, G., editor). Mineralogical Society, London.Google Scholar
Brindley, G.W. & Gillery, F.H. (1956) X-ray identification of chlorite species. Am. Miner. 41, 169–186.Google Scholar
Brown, G. & Brindley, G.W. (1980) X-ray diffraction procedures for clay mineral identification. Pp. 305-359 in: The X-ray Identification and Crystal Structures of Clay Minerals (Brindley, G.W. & Brown, G., editors). Mineralogical Society, London.Google Scholar
Brydon, J.E. & Heystek, H. (1958) A mineralogical and chemical study of the dikeland soils of Nova Scotia. Can. J. Soil Sci. 38, 171–186.CrossRefGoogle Scholar
Brydon, J.E. & Ross, G.J. (1966) Stability of chlorite in dilute acid solutions. Proc. Soil Sci. Soc. Am. 30, 740–744.CrossRefGoogle Scholar
Caillère, S. & Hénin, S. (1960) Relationship between the crystallochemical constitution of phyllites and their dehydration temperature application in the case of chlorites. Bull. Soc. Fr. Cdram. 48, 63–67.Google Scholar
Davey, B.G. & Low, P.F. (1968) Clay-water interaction as affected by hydrous aluminum oxide films. Trans. 9th Int. Congr. Soil Sci. 1, 607–616.Google Scholar
Droste, J.B., Bhattacharya, N. & Sunderman, J.A. (1962) Clay mineral alteration in some Indiana soils. Clays Clay Miner. 9, 329–342.CrossRefGoogle Scholar
El Rayah, H.M.E. & Rowell, D.L. (1973) The influence of iron and aluminium hydroxides on the swelling of Na-montmorillonite and the permeability of Na-soil. J. Soil Sci. 24, 137–144.CrossRefGoogle Scholar
Foster, M.G. (1962) Interpretation of the composition and a classification of the chlorites. U.S. Geol. Surv. Prof. Paper 414A.CrossRefGoogle Scholar
Frink, C. (1965) Characterization of aluminum interlayers in soil clays. Proc. Soil Sci. Soc. Am. 29, 379–382.CrossRefGoogle Scholar
Giese, R.F. (1980) Hydroxyl orientations and interlayer bonding in amesite. Clays Clay Miner. 28, 81–86.CrossRefGoogle Scholar
Gilkes, R.J. & Little, I.P. (1972) Weathering of chlorite and some associations of trace elements in Permian phyllites in southeast Queensland. Geoderma, 7, 233–247.CrossRefGoogle Scholar
Gray, D.H. & Schlocker, J. (1969) Electrochemical alteration of clay soils. Clays Clay Miner. 17, 309–322.CrossRefGoogle Scholar
Greenland, D.J. (1974) Determination of pH dependent charges of clays using caesium chloride and X-ray fluorescent spectrography. Trans. lOth Int. Congr. Soil Sci. Moscow, 2, 278–285.Google Scholar
Greenland, D.J. & Mott, C.J.B. (1978) Surfaces of soil particles. Pp. 321–353 in: Chemistry of Soil Constituents (Greenland, D. J. and Hayes, M. H. B., editors). Wiley, Chichester, UK.Google Scholar
Hatcher, J.T., Bower, C.A. & Clark, M. (1967) Adsorption of boron by soils as influenced by hydroxy aluminum and surface area. Soil Sci. 104, 422–426.CrossRefGoogle Scholar
Hsu, P.H. (1964) Adsorption of phosphate by aluminum and iron in soil. Proc. Soil Sci. Soc. Am. 28, 474–478.CrossRefGoogle Scholar
Jepson, W.B., Jeffs, D.S. & Ferris, A.P. (1976) The adsorption of silica on gibbsite and its relevance to the kaolinite surface. J. ColloM Interface Sci. 55, 454–461.CrossRefGoogle Scholar
Jones, A.A. & Greenland, D.J. (1980) Quantitative determination of the interlamellar volume in an interstratified mica-smectite soil clay. Clay Miner. 15, 175–191.CrossRefGoogle Scholar
Kidder, G. & Reed, L.W. (1972) Swelling characteristics of hydroxy-aluminum interlayered clays. Clays Clay Miner. 20, 13–20.CrossRefGoogle Scholar
Kodama, H. & Singh, S.S. (1972) Hydroxy aluminum sulfate montmorillonite complex. Can. J. Soil Sci. 52, 209–18.CrossRefGoogle Scholar
Mackenzie, R.C. & Milne, A.A. (1953) Effect of grinding on micas: I. Muscovite. Miner. Nag. 30, 178–185.Google Scholar
Mashali, A.M. (1977) The charge characteristics of clays, oxides and hydrous oxide minerals. Ph.D. thesis, University of Reading.Google Scholar
Murray, H.H. & Leininger, R.K. (1956) Effect of weathering on clay minerals. Clays Clay Miner. 4, 340–347.CrossRefGoogle Scholar
Norrish, K. & Chappell, B.W. (1967) X-ray fluorescence spectrography. Pp. 201–272 in: Methods in Determinative Mineralogy (Zussman, J., editor). Academic Press, London.Google Scholar
Phillips, W.R. (1963) A differential thermal study of the chlorites. Miner. Nag. 33, 404–414.Google Scholar
Quirk, J.P. (1955) Significance of surface areas calculated from water vapour sorption isotherms by use of the BET equation. Soil Sci. 80, 423–430.CrossRefGoogle Scholar
Rich, C.I. (1968) Hydroxy interlayers in expansible layer silicates. Clays Clay Miner. 16, 15–30.CrossRefGoogle Scholar
Ross, G.J. (1969) Acid dissolution of chlorites: release of magnesium, iron and aluminum and mode of acid attack. Clays Clay Miner. 17, 347–354.CrossRefGoogle Scholar
Ross, G.J. (1975) Experimental alteration of chlorites into vermiculites by chemical oxidation. Nature, 255, 133–134.CrossRefGoogle Scholar
Roth, C.B., Jackson, M.L. & Syers, J.K. (1969) Deferration effect on structural ferrous-ferric ratio and CEC of vermiculite and soils. Clays Clay Miner. 17, 253–264.CrossRefGoogle Scholar
Sawney, B.L. (1968) Aluminum interlayers in layer silicates. Effect of OH/A1 ratio of A1 solution, time of reaction and type of structure. Clays Clay Miner. 16, 157–163.CrossRefGoogle Scholar
Schofield, R.K. & Samson, H.R. (1954) Flocculation of kaolinite due to the attraction of oppositely charged faces. Discuss. Farad. Soc. 18, 135-145.CrossRefGoogle Scholar
Smykatz-Kloss, W. (1974) Differential Thermal Analysis, p. 124. Springer-Verlag, Berlin.CrossRefGoogle Scholar
Stephen, I. (1952) A study of rock weathering with reference to the soils of the Malvern Hills. II. Weathering of appinite and ‘ivy scar rock'. J. Soil Sci. 3, 219–37.CrossRefGoogle Scholar
Tamura, T. (1957) Identification of the 14 A clay mineral component. Am. Miner. 42, 107–110.Google Scholar