ESR and IR Evidence for Chromium in Kaolinites

Clay Minerals - Tập 28 Số 3 - Trang 353-364 - 1993
C. Mosser1, Sabine Petit2, M. M. Mestdagh3
1Centre de Géchimie de la Surface, 1 rue Blessig, F-67084 Strasbourg Cédex, France
2Laboratoire de Pétrologie de la Surface, URA CNRS 721, Université de Poitiers, 40 Avenue du Recteur Pineau, F-86022 Poitiers Cddex, France, and
3Laboratoire de Chimie des Interfaces, Université Catholique de Louvain, Place Croix du Sud 1, 2/18 B-1348 Louvain la Neuve, Belgique

Tóm tắt

AbstractEvidence obtained from ESR and IR studies is presented for the presence of structural Cr in two natural kaolinites (MILO and GEY) formed in an hydrothermal environment in Sonoma County, California. The XRD patterns show a greater structural disorder for GEY than for MILO, but both have the usual hexagonal shapes as shown by TEM observations. On the basis of EDX analysis of different particles, GEY, on average, appears to be richer in Cr (2.1% Cr203) than MILO (0.6% Cr203). The presence of Fe oxide particles containing some Cr, Ni and V is also indicated by EDX analysis. By FT-IR observation, the octahedral Cr3+position was easily detected by a well resolved spectral feature at 3586 cm-1. The adsorbed Cr3+kaolinite (KMRXCR) presents no band at 3586 cm-1, but two other bands situated at 3527 and 3477 cm-1. The main features of the ESR spectra of these two kaolinites are a set of resonances neargeff4; a broad resonance centred neargeff2 with some modulations; and a set of resonances near gcffl. The broad resonance centred neargeff2 is interpreted as the free iron oxide signal with modulations due to VO2+. The set of resonances neargeff4 is similar to that observed for octahedral Fe3+, but the position is shifted compared to that of octahedral Fe 3+. This set of resonances neargeff4 is, therefore, interpreted as belonging to Cr3+in octahedral position. The resonances atgeff1 are also interpreted as belonging to Cr3-. Comparison with the Cr3+surface-adsorbed ESR signal of a Cr-saturated kaolinite (which is a broad resonance centred neargeff2) strengthens the interpretation of thegeff4 resonances belonging to Cr3+in the octahedral position. The results obtained by the combination of FT-IR and ESR spectroscopics indicate that Cr3+is present in the octahedral position of the MILO and GEY kaolinites.

Từ khóa


Tài liệu tham khảo

10.2113/gsecongeo.84.3.694

10.1016/S0020-1693(00)90237-8

Matzat, 1978, Handbook of Geochemistry

Bonnin, 1982, Le fer dans les kaolins. Etude par spectrometries RPE, Mossbauer, EXAFS, Bull. Mineral., 105, 467

Maksimovic, 1973, Infrared study of chromium-bearing halloysites, Proc. Int. Clay Conf., Madrid,, 61

10.1180/claymin.1975.010.5.01

Maksimovic, 1991

10.1346/CCMN.1990.0380605

Maksimovic, 1968, Halloysite and kaolinite formed through the alteration of ultramafic rocks, Trans. Int. Geol. Congress, Prague,, 14, 95

10.2136/sssaj1974.03615995003800030014x

10.1180/minmag.1975.040.309.12

10.1016/0009-2541(74)90002-3

10.1180/claymin.1980.015.4.01

10.1180/claymin.1990.025.2.04

10.1088/0953-8984/5/28/008

10.1180/mono-4

10.1346/CCMN.1973.0210518

10.1346/CCMN.1983.0310407

10.1346/CCMN.1977.0250608

10.1346/CCMN.1978.0260402

10.1016/S0883-2927(09)80077-2

Ambrosi, 1984, Petrologie et geochimie d’une sequence de profils lateriques cuirasses ferrugineux de la region de Diouga, Burkina Faso.

10.1180/claymin.1981.016.1.05

Gritsaienko, 1949, O khromovom galluazite iz Aidyrlinskogo mestorozdheniyana juzhnom Urale, Zapiski. Vses. Mineral. Obshchestva,, 78, 61

Samuel, 1985, Analyse multiēlēmentaire standardisee des materiaux geologiques en spectrometrie d’emission par plasma a couplage inductif, Analusis,, 13, 312

10.1346/CCMN.1981.0290307

Brindley, 1980, Crystal Structures of Clay Minerals and their X-ray Identification. Monograph 5,, 10.1180/mono-5

10.1180/claymin.1980.015.4.10

10.1180/claymin.1974.010.4.03

10.1346/CCMN.1977.0250602

10.1346/CCMN.1962.0110122

Mestdagh, 1982, Evaluation du role du fer structural sur la cristallinitē des kaolinites, Bull. Mineral., 105, 457

10.1346/CCMN.1991.0390602

Cases, 1982, Etudes des proprietēs cristallochimiques, morphologiques, superficielles de kaolinite desordonnees, Bull. Mineral.

10.1016/0009-2541(86)90059-8

Angel, 1972, Electron spin resonance studieds of kaolins., Proc. Int. Clay Conf. Madrid,

10.1346/CCMN.1979.0270203

10.1180/claymin.1976.011.3.03

10.1021/j100603a010

10.3406/argil.1975.1243

Samuel, 1983, Unpub. Notes Techniques Inst. Geol

Wherry, 1916, An American occurrence of miloschite, Am. Miner., 63

10.1346/CCMN.1980.0280408

10.1180/claymin.1980.015.1.01

10.1180/claymin.1974.010.4.04

Besnus, 1973, Methode d’analyse des roches au spectrometre d’arc a lecture directe par un dispositif d’electrode rotative, Analusis,, 2, 111

Pampuch, 1966, Infrared study of thermal transformations of kaolinite and the structure of metakaolin, Prace Mineralogiczne,, 6, 53

10.1180/claymin.1963.005.29.07

Thông tin
Thông tin xuất bản

Clay Minerals

Tập 28 Số 3

353-364

Thông tin tác giả