Glass–iron–clay interactions in a radioactive waste geological disposal: An integrated laboratory-scale experiment

A comparative review of the aqueous corrosion of glasses, crystalline ceramics, and metals

“…For instance, the literature reports several results of a detrimental effect of iron corrosion products on glass because the formation of the passivating layer is delayed or prevented by sorption of Si onto iron compounds and more importantly by precipitation of iron silicates. 18,21,57,82,83 Precipitation of silicate minerals is an additive process: in the case of phyllosilicate precipitation, experimentally sustained by the regular supply of Fe, Mg, Ni, or Co by the aqueous environment, the alteration rate of the glass increases proportionally to the amount of secondary precipitated phases. 84 When Mg is supplied by Mg-bearing minerals, both dissolution of the primary phase and transport of reactive species can affect the composition and the thickness of the passivating layer, and thus the alteration rate.…”

Stability of Clay Barriers Under Chemical Perturbations

“…In experiments involving bentonite, the primary Sm is strongly altered (De Combarieu, 2007;Perronnet et al, 2007;Mosser-Ruck et al, 2010). Along with the influx of iron, the system evolves with the precipitation of either Fe-serpentine (Lantenois et al, 2005;Perronnet et al, 2008;Schlegel et al, 2008Schlegel et al, , 2010De Combarieu et al, 2011;Jodin-Caumon et al, 2012;Bourdelle et al, 2014) or iron-rich Sm (Guilllaume et al, 2004;Charpentier et al, 2006;Wilson et al, 2006a).…”

“…Mineral characterization from iron-clay mineral interaction systems in a wide range of conditions show that magnetite (sometimes associated with maghemite g-Fe 2 O 3 ) is commonly observed adhering to the iron surface in most of the occurrences (experiments and archaeological artifacts) either as (1) a submicrometric internal corrosion layer (Lantenois et al, 2005;Charpentier et al, 2006;Smart et al, 2006;Carlson et al, 2007;Martin et al, 2008;Schlegel et al, 2008Schlegel et al, , 2010De Combarieu et al, 2011;Schlegel et al, 2014) or (2) a thinner, sometimes discontinuous, layer (w10e100 nm) as observed using scanning transmission X-ray microscopy (Michelin et al, 2012). This internal corrosion layer is thought to be at the origin of the passivation effect controlling the corrosion rate.…”

“…External corrosion products precipitating at the surface of magnetite include iron carbonates (Ca incorporating siderite (Fe,Ca)CO 3 and chukanovite Fe 2 (OH) 2 CO 3 ) and iron silicates (Fe-serpentine-type minerals, greenalite Fe 3 Si 2 O 5 (OH) 4 , cronstedtite Fe 4 SiO 5 (OH) 4 ) (Wilson et al, 2006a;Martin et al, 2008;Perronnet et al, 2008;Schlegel et al, 2008Schlegel et al, , 2010De Combarieu et al, 2011). The actual mineral paragenesis results from the competition between the mineral dissolution and precipitation kinetics, the local geochemical conditions (pH, Eh), and the transport of reaction products.…”

Role of vein-phases in nanoscale sequestration of U, Nb, Ti, and Pb during the alteration of pyrochlore

“…1). Previous experimental studies on the alteration of waste glasses also report the formation of Fe-Mg silicates with (Fe+Mg):Si molar ratios of 1:1, and Fe:Si molar ratios of 3:2 in near-surface areas of the altered waste glass, specifically in or on the amorphous gel layer (Grambow, 2006;de Combarieu et al, 2011;Poinssot and Gin, 2012;Burger et al, 2013;Jollivet et al, 2012;Rolland et al, 2013).…”