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Journal ArticleDOI

Expansion behaviour of commercial vermiculites at 1000 °C

01 Apr 2010-Applied Clay Science (Elsevier)-Vol. 48, Iss: 3, pp 492-498
TL;DR: In this paper, commercial vermiculites from different places were studied in order to know the cause of their different behaviour after abrupt heating at 1000°C. Mossbauer spectroscopy provided Fe 2+ and Fe 3+ contents and allowed identification of both tetrahedral and octahedral iron.
About: This article is published in Applied Clay Science.The article was published on 2010-04-01. It has received 54 citations till now.
Citations
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Journal ArticleDOI
TL;DR: In this article, high-angle annular dark-field scanning transmission electron microscopy showed that Cs+ ions in the Mg-Phl layers were intercalated deep within the crystal structure, along specific interlayer regions.
Abstract: Potassium (K+) phlogopite was transformed to a vermiculite-like mineral through a topotactic reaction under acidic conditions (pH 2) followed by hydrothermal treatment with Na+, Mg2+, Ca2+, and Al3+ cations. The resulting Na+-, Mg2+-, Ca2+-, and Al3+-altered phlogopites (Phl) denoted as Na-Phl, Mg-Phl, Ca-Phl, and Al-Phl, respectively. Na-Phl, Mg-Phl, and Ca-Phl all exhibited the same high adsorption capacity as natural vermiculite and the absorption of Cs+ and Sr2+ ions on these materials followed the Langmuir model. High-angle annular dark-field scanning transmission electron microscopy showed that Cs+ ions in the Mg-Phl layers were intercalated deep within the crystal structure, along specific interlayer regions. These adsorbed anhydrous Cs+ ions were firmly fixed at the centers of hexagonal rings positioned simultaneously in the upper and lower tetrahedral silicate sheets, whereas Sr2+ ions adsorb into the interlayer in the hydrous state. Al-Phl formed a hydroxyl-interlayered vermiculite and demonstra...

62 citations

Journal ArticleDOI
TL;DR: In this paper, three kinds of salt solutions including NaCl, CaCl2 and MgCl2 were used to modify the expansion of vermiculite, and X-ray diffraction results indicate that vermiculate has been successfully modified by salt solutions.

53 citations


Cites background from "Expansion behaviour of commercial v..."

  • ...Vermiculite can be expanded by several times in volume when heated rapidly due to the sudden release of interlayer water [1,2]....

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Journal ArticleDOI
TL;DR: In this paper, a vermiculite from Egypt was chemically activated by leaching with 0.5 m HCl solution or by treatment with 30% H 2 O 2 solution.

45 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of microwave energy on the product bulk density is provided for the three most relevant grades of material and it is shown as to how the performance of the system is significantly better than conventional exfoliation technology, in terms of produced bulk densities, energy efficiencies, temperature of the product and plant footprint.

41 citations

Journal ArticleDOI
TL;DR: In this article, the influence of vermiculite injection on coal ash deposition during the combustion of Zhundong coal was investigated by inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), scanning electron microscopy-energy-dispersive spectrometers (SEM-EDS).
Abstract: The additive injection technology has been effective in alleviating slagging and fouling during coal combustion. In this study, experiments were conducted in a drop-tube furnace to understand the influence of vermiculite injection on ash deposition during the combustion of Zhundong coal. The interaction between coal ash and vermiculite was investigated by inductively coupled plasma optical emission spectrometry (ICP–OES), X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive spectrometry (SEM–EDS). Results show that deposits formed at 1100 °C with vermiculite additive are more friable and polyporous than those without vermiculite additive, and these deposits can be easily removed. The mechanisms behind this phenomenon can be explained as follows: (1) The agglomeration of ash particles is inhibited by the partition of low-viscosity slices formed through vermiculite swelling after heat treatment. (2) Intermetallic reactions occur on the surface of vermiculite particles, resulting in the fo...

38 citations

References
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Book
01 Jun 1982
TL;DR: In the years 1930-1950 clay mineral identification involved mainly a combination of X-ray powder diffraction and chemical analysis with some assistance from other techniques, notably differential thermal analysis.
Abstract: In the years 1930—1950 clay mineral identification involved mainly a combination of X-ray powder diffraction and chemical analysis with some assistance from other techniques, notably differential thermal analysis. In the period 1950—1970 additional procedures have emerged including infrared analysis, electron optical methods and a variety of thermal methods. These procedures are now treated in other monographs sponsored by the Mineralogical Society and in many other publications. Despite the availability of other techniques, X-ray diffraction remains a basic tool for studying minerals and we hope that this monograph will continue to serve, as did the previous editions, both those concerned with the more academic aspects of clay mineralogy and also those, such as geologists, civil engineers and soil scientists, for whom identification and quantitative estimation of the minerals in natural clayey materials is a practical requirement.

3,090 citations

Book
01 Jan 2006
TL;DR: The history of Clay Science: A Young Discipline 16. as mentioned in this paper The history of clay science: A Great Perspective and teaching Clay Science, a Great Perspective: Teaching Clay Science from a Teacher's Perspective
Abstract: 1. General Introduction: Clays, Clay Minerals, and Clay Science 2. Structures and Mineralogy of Clay Minerals 3. Surface and Interface Chemistry of Clay Minerals 4. Synthetic Clay Minerals and Purification of Natural Clays 5. Colloid Clay Science 6. Mechanical Properties of Clays and Clay Minerals 7. Modified Clays and Clay Minerals 8. Properties and Behavior of Iron in Clay Minerals 9. Clays, Microorganisms and Biomineralisation 10. Clays in Industry 11. Clays, Environment and Health 12. Critical Assessment of Some Analytical Techniques 13. Some Other Materials Related to Clays 14. Genesis of Clay Minerals 15. History of Clay Science: A Young Discipline 16. Teaching Clay Science: A Great Perspective

1,443 citations


"Expansion behaviour of commercial v..." refers background in this paper

  • ...The hydration properties of 2:1-clay minerals are controlled to a large extent by the interlayer cations (for instance, see Hendricks et al., 1940; Mooney et al., 1952; Suquet et al., 1975; Bergaya et al., 2006)....

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  • ...…investigated because of their remarkable physical and chemical properties: low thermal conductivity and density, refractory behaviour, and high cation exchange capacity, properties that lead to various industrial applications (Strand and Stewart, 1983; Hindman, 1992; Bergaya et al., 2006)....

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  • ...…their layer charge, of disorder effects, and of their ability for dehydration–rehydration and the associated swelling processes (Mathieson and Walker, 1954; Shirozu and Bailey, 1966; Grim, 1968; Brown and Brindley, 1980; de la Calle and Suquet, 1988; de la Calle et al., 1988; Bergaya et al., 2006)....

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BookDOI
01 Jan 1984
TL;DR: The early days of the effect of Mossbauer spectroscopy on hard magnetic materials are described in this paper... and the potential of using it in the field of biological mineralization is discussed.
Abstract: 1. The Early Days of the Effect.- 2. Mossbauer Effect Studies of Hard Magnetic Materials.- 3. Mossbauer Effect Studies of Oxidic Spinels.- 4. Evaluation of Distributed Hyperfine Parameters.- 5. Radio Frequency Field-Induced Effects in Ferromagnetic Materials.- 6. Mossbauer Spectroscopic Studies of the High Oxidation States of Iron.- 7. Mossbauer Spectroscopic Studies of Intercalation Compounds.- 8. Mossbauer Spectroscopy of Iron and Iron-Molybdenum Hydrotreating Catalysts.- 9. The Use and Potential of Mossbauer Spectroscopy in Studies of Biological Mineralization.- 10. Characterization of Semiconductors by Mossbauer Spectroscopy.- 11. Mossbauer Spectroscopy of Europium-Containing Compounds.- Author Index.

979 citations

Book ChapterDOI
01 Jan 1980

643 citations


"Expansion behaviour of commercial v..." refers background in this paper

  • ...They present a wide variety of physical–chemical properties as a result of their lamellar structure, of their layer charge, of disorder effects, and of their ability for dehydration–rehydration and the associated swelling processes (Mathieson and Walker, 1954; Shirozu and Bailey, 1966; Grim, 1968; Brown and Brindley, 1980; de la Calle and Suquet, 1988; de la Calle et al., 1988; Bergaya et al., 2006)....

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  • ...On the other way, it is known that: a) Structural Fe and Fe both significantly impact the smectite–water interaction (Stucki, 1988); b) The swellability of sheet-silicates as vermiculite is affected by the cationic composition of the interlayer space (Mathieson and Walker, 1954; Shirozu and Bailey, 1966; Grim, 1968; Brown and Brindley, 1980; de la Calle and Suquet, 1988); and c) the presence of reduced structural iron has a depressing effect on water retention capacity in smectites (Yan and Stucki, 1999, 2000)....

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  • ...…their layer charge, of disorder effects, and of their ability for dehydration–rehydration and the associated swelling processes (Mathieson and Walker, 1954; Shirozu and Bailey, 1966; Grim, 1968; Brown and Brindley, 1980; de la Calle and Suquet, 1988; de la Calle et al., 1988; Bergaya et al., 2006)....

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  • ...…as vermiculite is affected by the cationic composition of the interlayer space (Mathieson and Walker, 1954; Shirozu and Bailey, 1966; Grim, 1968; Brown and Brindley, 1980; de la Calle and Suquet, 1988); and c) the presence of reduced structural iron has a depressing effect on water retention…...

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