Stability of lanthanum-saturated montmorillonite under high pressure and high temperature conditions

Stefani, Vicente Fiorini; Conceição, Rômmulo Vieira; Carniel, Larissa Colombo; Balzaretti, Naira Maria

doi:10.1016/j.clay.2014.10.012

Cited by 13 publications

(12 citation statements)

References 32 publications

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“…The difference in the basal spacing between La and Ca montmorillonites is similar to (even somewhat higher) that reported in Stefani et al [18].…”

Section: Results Of Xrdsupporting

confidence: 70%

“…Furthermore, a surprising information studied about the structural Fe, which is oppose to the studies of Evgeny et al [20], and Stefani et al [18] that during cation exchange procedure no other crystalline phase formed but octahedral Fe may moves into interlayer phase.…”

Section: Introductioncontrasting

confidence: 41%

“…The nature of these complexes does not change with temperature. Stefani et al [18] studied the lanthanum-saturated montmorillonite under high pressure and high temperature. Under these conditions the structure becomes muscovite-like and rich in La 3+ .…”

Section: Introductionmentioning

confidence: 99%

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Preparation and structure’s analyses of lanthanide (Ln) -exchanged bentonites

Kovács

Baradács

Kónya

et al. 2017

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Please cite this article as: Eszter Mária Kovács, Eszter Erdélyiné Baradács, Péter Kónya, Péter Kovács-Pálffy, Sándor Harangi, József Kónya, Noémi M.Nagy, Preparation and structure's analyses of lanthanide (Ln) -exchanged bentonites, Colloids and Surfaces A: Physicochemical and Engineering Aspects http://dx.doi.org/10. 1016/j.colsurfa.2017.02.085 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. HIGHLIGHTS REE-exchanged bentonites were prepared from Ca-bentonite by ion exchange.  The La 3+ -, Ce 3+ -, and Gd 3+ -bentonite, the sorbed ion amount was higher than the CEC.  In case of lanthanum-bentonite, the rare earth quantity is as high as 136% of CEC.  The iron(III) content of lanthanum bentonite is less than that of the original Cabentonite. 4Abstract The interaction between Lanthanides (Ln)-ions and Ca-bentonite and the structural changes accompanying were studied. Ln-exchanged bentonites were prepared from Cabentonite (Istenmezeje, Hungary) by ion exchange in three consecutive washings with lanthanide solutions. Scanning Eletronmicroscopy Energy Dispersive X-ray spectroscopy (SEM-EDX) studies showed even distribution of Lns and other components of bentonite. The natural bentonite and the lanthnide exchanged bentonites were characterized by X-ray diffraction (XRD), which revealed the same mineral composition, and the increase of the basal spacing of montmorillonite from 1.465 (Ca 2+ ) to 1.577 nm (REE 3+ ). The d001 basal spacing of lanthanide montmorillonite increases as the ion radius of the lanthanide cation increases. The Fe 3+ , and Lns 3+ amount on the bentonite were determined by X-rayfluorescence spectrometry (XRF) elemental analysis. The amount of exchanged Lns were determined by washing the Ln-bentonite with 1M ammonium-acetate, and measuring the amount of Ln released, using inductively coupled plasma optical emission spectrometry (ICP-OES). In most Ln-bentonites, the quantity of the exchanged Ln ions was about 80-90% of the cation exchange capacity (CEC) of the bentonite. In case of some lanthanides bentonite (La 3+ , Ce 3+ , and Gd 3+ ), however, the sorbed quantity of lanthanum ions was higher than the cation exchange capacity. In case of lanthanum-bentonite, the lanthanide quantity is as high as 136% of CEC. Moreover, the iron(III) content of lanthanum bentonite is less than that of the original Ca-bentonite. Mössbauer spectra of the La-, Ce-, and Gd-exchanged samples at 78 K revealed an unexpected magnetically split component that was absent from the Ca-bentonite. This component may belong to interlayer Fe. This iron can be released from the octahedral positions crystal lattice.5

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“…The difference in the basal spacing between La and Ca montmorillonites is similar to (even somewhat higher) that reported in Stefani et al [18].…”

Section: Results Of Xrdsupporting

confidence: 70%

Section: Introductioncontrasting

confidence: 41%

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Preparation and structure’s analyses of lanthanide (Ln) -exchanged bentonites

Kovács

Baradács

Kónya

et al. 2017

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…В первую можно включить способы, повышающие пло-щадь активной поверхности глин, во вто-рую -технологии, направленные на по-вышение энергетической активности этих поверхностей. Однако, несмотря на зна-чительное количество технологий, спо-собствующих повышению сорбционной способности глин, экспериментальных исследований недостаточно (Friedlander et al, 2016;Sun et al, 2015;Stefani et al, 2014). Особый интерес представляют исследова-ния, связанные с воздействием на глини-стый грунт давления, посредством кото-рого должны изменяться структурно-текстурные особенности грунтов, их со-став, состояние и физико-химические свойства и, как следствие, сорбционные способности глин.…”

Section: Introductionunclassified

To the Problem of the Clay Particles Energy Potential Assessment

Seredin¹,

Parshina²,

Исаева³

2017

ВПУГ

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“…The occurrence of rare earths in several products can improve their applicability due to advantageous properties of lanthanoides like unique electron con-figuration, fluorescence, high refractive index, high magnetic anisotropy, high electrical conductivity and high oxygen storage and release capacity. The exchange of the interlayer cations of montmorillonite with the ions of rare earth elements is an effective approach to obtain catalysts, catalyst supports, sensors and adsorbents [4][5][6]. Mössbauer spectroscopy has been widely applied [7][8][9] to study the microenvironments of iron atoms occurring in montmorillonite.…”

Section: Introductionmentioning

confidence: 99%

Magnetic sublattices in Np2Co17 and Np2Ni17

et al. 2016

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Novel montmorillonites were prepared by the exchange of the interlayer cations with a series of rare earth cations (La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, and Er) and characterized by XRD, XRF, SEM, chemical analysis and 57 Fe Mössbauer spectroscopy. An unexpected magnetically split component, assigned to iron being in the interlayer space, was observed in the Mössbauer spectra at 78K in some rare earth cation exchanged montmorillonite. This paper is the initial report about this observation. The transition of iron from the octahedral site to the interlayer and possible incorporation of rare earths in sites different from those which are in the interlayer space was concluded.

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Stability of lanthanum-saturated montmorillonite under high pressure and high temperature conditions

Cited by 13 publications

References 32 publications

Preparation and structure’s analyses of lanthanide (Ln) -exchanged bentonites

Preparation and structure’s analyses of lanthanide (Ln) -exchanged bentonites

To the Problem of the Clay Particles Energy Potential Assessment

Magnetic sublattices in Np2Co17 and Np2Ni17

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