A combined glass dissolution/diffusion experiment in Boom Clay at 30°C

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A combined glass dissolution/diffusion experiment in Boom Clay at 30°C. / Aertsens, Marc; Lemmens, Karel; Ferrand, Karine (Peer reviewer).

In: Physics and Chemistry of the Earth, Vol. 65, 05.2013, p. 72-78.

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@article{51bb3a612deb4ce08b4813f5eaff0902,
title = "A combined glass dissolution/diffusion experiment in Boom Clay at 30°C",
abstract = "Silica diffusion in clay is possibly the rate determining process for the dissolution of vitrified waste disposed of in a clay layer. For testing this hypothesis, combined glass dissolution/ silica diffusion experiments are performed. Glass coupons doped with 32Si are sandwiched between two clay cores at 30°C. Due to glass dissolution, 32Si is released and diffuses into the clay. At the end of an experiment, the glass mass loss is measured and the diffusion profile of the 32Si in the clay is determined. Both mass loss and the 32Si diffusion profile in clay are described well by a model combining glass dissolution according to a linear rate law with silica diffusion in clay. Fitting leads to an apparent silica diffusion coefficient between 7×10-13 m2/s and 1.2×10-12 m2/s. The maximal glass dissolution rate for glass next to clay is around 1.6×10-7 gram glass/m2 s. In clay, the measured silica concentration is around 5 mg/liter. Combining these values with the previously measured product of accessible porosity and retardation factor, leads in two ways to a silica glass saturation concentration in clay between 8 and 10 mg Si/liter.",
keywords = "Boom Clay, silica, glass dissolution, diffusion accessible porosity, retardation factor, apparent diffusion coefficient",
author = "Marc Aertsens and Karel Lemmens and Karine Ferrand",
note = "Score = 10",
year = "2013",
month = "5",
doi = "10.1016/j.pce.2013.05.008",
language = "English",
volume = "65",
pages = "72--78",
journal = "Physics and Chemistry of the Earth",
issn = "1474-7065",
publisher = "Elsevier",

}

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TY - JOUR

T1 - A combined glass dissolution/diffusion experiment in Boom Clay at 30°C

AU - Aertsens, Marc

AU - Lemmens, Karel

A2 - Ferrand, Karine

N1 - Score = 10

PY - 2013/5

Y1 - 2013/5

N2 - Silica diffusion in clay is possibly the rate determining process for the dissolution of vitrified waste disposed of in a clay layer. For testing this hypothesis, combined glass dissolution/ silica diffusion experiments are performed. Glass coupons doped with 32Si are sandwiched between two clay cores at 30°C. Due to glass dissolution, 32Si is released and diffuses into the clay. At the end of an experiment, the glass mass loss is measured and the diffusion profile of the 32Si in the clay is determined. Both mass loss and the 32Si diffusion profile in clay are described well by a model combining glass dissolution according to a linear rate law with silica diffusion in clay. Fitting leads to an apparent silica diffusion coefficient between 7×10-13 m2/s and 1.2×10-12 m2/s. The maximal glass dissolution rate for glass next to clay is around 1.6×10-7 gram glass/m2 s. In clay, the measured silica concentration is around 5 mg/liter. Combining these values with the previously measured product of accessible porosity and retardation factor, leads in two ways to a silica glass saturation concentration in clay between 8 and 10 mg Si/liter.

AB - Silica diffusion in clay is possibly the rate determining process for the dissolution of vitrified waste disposed of in a clay layer. For testing this hypothesis, combined glass dissolution/ silica diffusion experiments are performed. Glass coupons doped with 32Si are sandwiched between two clay cores at 30°C. Due to glass dissolution, 32Si is released and diffuses into the clay. At the end of an experiment, the glass mass loss is measured and the diffusion profile of the 32Si in the clay is determined. Both mass loss and the 32Si diffusion profile in clay are described well by a model combining glass dissolution according to a linear rate law with silica diffusion in clay. Fitting leads to an apparent silica diffusion coefficient between 7×10-13 m2/s and 1.2×10-12 m2/s. The maximal glass dissolution rate for glass next to clay is around 1.6×10-7 gram glass/m2 s. In clay, the measured silica concentration is around 5 mg/liter. Combining these values with the previously measured product of accessible porosity and retardation factor, leads in two ways to a silica glass saturation concentration in clay between 8 and 10 mg Si/liter.

KW - Boom Clay

KW - silica

KW - glass dissolution

KW - diffusion accessible porosity

KW - retardation factor

KW - apparent diffusion coefficient

UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_133670

UR - http://knowledgecentre.sckcen.be/so2/bibref/11158

U2 - 10.1016/j.pce.2013.05.008

DO - 10.1016/j.pce.2013.05.008

M3 - Article

VL - 65

SP - 72

EP - 78

JO - Physics and Chemistry of the Earth

JF - Physics and Chemistry of the Earth

SN - 1474-7065

ER -

ID: 218362