Polymerization of silicate and aluminate tetrahedra in glasses, melts, and aqueous solutions—IV. Aluminum coordination in glasses and aqueous solutions and comments on the aluminum avoidance principle

Jong, B.H.W.S. de; Schramm, Charles M.; Parziale, Victor E.

doi:10.1016/0016-7037(83)90064-9

Cited by 100 publications

(38 citation statements)

References 64 publications

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“…Qualitatively, they do so if they crystallize from aqueous solutions having sufficiently high concentrations of tetrahedral A1. A similar suggestion was made in passing by de Jong et al (1983).…”

Section: Introductionsupporting

confidence: 79%

Aqueous-Chemical Control of the Tetrahedral-Aluminum Content Of Quartz, Halloysite, and other Low-Temperature Silicates

Merino

Harvey

Murray

1989

Clays and clay miner.

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Abstract--Aqueous AI passes from octahedral to tetrahedral coordination over a narrow pH interval, or threshold. This interval is 5.5-6.5 at 25~ and shifts to lower pH as temperature increases. The concentration of aqueous tetrahedrally coordinated A1 is a quasi-step function of the solution pH, and, by the mass-action law, so should be the amount of tetrahedral A1 incorporated by a silicate that crystallizes from the aqueous solution. Qualitative support for this prediction (which applies to quartz, opal-CT, kaolin-group minerals, pyrophyllite, micas, chlorites, and other low-temperature silicates) comes from the very topology of equilibrium activity diagrams and from several pairs of associated waters and authigenic silicates from weathering, hydrothermal, and diagenetic environments. The uptake of tetrahedral A1 also depends on the aqueous concentrations of monovalent cations and silica, and on the mineral's structural constraints.Solid solution of tetrahedral A1 in halloysite in turn produces the characteristic bent or tubular crystals of this mineral. This genetic link between aqueous chemistry (mainly pH), tetrahedral-A1 uptake by a low-temperature silicate, and the mineral's crystal morphology may operate also in other silicates.

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Section: Introductionsupporting

confidence: 79%

Aqueous-Chemical Control of the Tetrahedral-Aluminum Content Of Quartz, Halloysite, and other Low-Temperature Silicates

Merino

Harvey

Murray

1989

Clays and clay miner.

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“…The pioneering investigations targeting the local structure of AS glasses by magic-angle-spinning (MAS) NMR [1][2][3][4][5][6][7], as well as by other techniques, primarily Raman spectroscopy [8][9][10][11], were carried out during the 1980s. They emanated into the "conventional" structural model outlined herein in Section 3.…”

Section: Introductionmentioning

confidence: 99%

27Al NMR Studies of Aluminosilicate Glasses

Edén

2015

Annual Reports on NMR Spectroscopy

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“…To understand the aging of a leached glass (or glass ceramic GCM) gel layer into either clay or zeolite mineral assemblages, it is important to recognize that the hydrated gel layer exhibits acid/base properties that are manifested as the pH dependence of the thickness and nature of the gel layer [138]. The alteration of aluminosilicate gels (artificial or natural) to clay or zeolites is also pH dependent, with clay formation favoring less basic aging environments than zeolites [139]. Thus, if the solution pH changes while the gel ages, clay mineral species may convert into zeolite mineral species in response to an increase in pH.…”

Section: Srnl-sti-2009-00626 March 2010mentioning

confidence: 99%

Durable Glass for Thousands of Years

Jantzen

Brown

Pickett

2010

Int J of Appl Glass Sci

180

156

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The durability of natural glasses on geological time scales and ancient glasses for thousands of years is well documented. The necessity to predict the durability of high level nuclear waste (HLW) glasses on extended time scales has led to various thermodynamic and kinetic approaches. Advances in the measurement of medium range order (MRO) in glasses has led to the understanding that the molecular structure of a glass, and thus the glass composition, controls the glass durability by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. During the early stages of glass dissolution, a "gel" layer resembling a membrane forms through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer ages into clay or zeolite minerals by Ostwald ripening. Zeolite mineral assemblages (higher pH and Al 3+ rich glasses) may cause the dissolution rate to increase which is undesirable for long-term performance of glass in the environment. Thermodynamic and structural approaches to the prediction of glass durability are compared versus Ostwald ripening.

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Polymerization of silicate and aluminate tetrahedra in glasses, melts, and aqueous solutions—IV. Aluminum coordination in glasses and aqueous solutions and comments on the aluminum avoidance principle

Cited by 100 publications

References 64 publications

Aqueous-Chemical Control of the Tetrahedral-Aluminum Content Of Quartz, Halloysite, and other Low-Temperature Silicates

Aqueous-Chemical Control of the Tetrahedral-Aluminum Content Of Quartz, Halloysite, and other Low-Temperature Silicates

27Al NMR Studies of Aluminosilicate Glasses

Durable Glass for Thousands of Years

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