Sorption of water by La-montmorillonite as a mechanism for La retention at 300°

The interaction of trivalent La, simulating Am, with poten¬ tial backfill clay minerals for radioactive waste storage is of interest under simulated repository condition of 300 eC. The effect of heating on the swelling and water adsorption capacity of lanthanum saturated montmorillonite has been investigated. Sodium and lith¬ ium as exchangeable ions have also been included with comparative purposes. XPS, XRD and FT-IR measurements have been used to elucidate the interaction mechanism of La(III) with montmorillonite upon heating. The fixation of lanthanum should be ascribed exclusively to the hydrolysis of the hydrated ions.Castro M.A., Poyato Juan, Tobias M.Milagro, Trillo José M. Sorption of water by La-montmorillonite as a mechanism for La retention at 300°. In: Proceedings of the 9th international Clay Conference, Strasbourg, 1989. Vol III : Geochemistry of clays. Nuclear waste disposal. Strasbourg : Institut de Géologie – Université Louis-Pasteur, 1990. pp. 55-62. (Sciences Géologiques. Mémoire, 87