title: Ni phases formed in cement and cement systems under highly alkaline conditions: an XAFS study.
abstract: X-ray absorption fine structure (XAFS) spectroscopy was applied to assess the solubility-limiting phase of Ni in cement and cement minerals. The study reveals the formation Ni and Al containing hydrotalcite-like layered double hydroxides (Ni-Al LDHs) when cement material (a complex mixture of CaO, SiO2, Al2O3, Fe2O3 and SO3) was treated with Ni in artificial cement pore water under highly alkaline conditions (pH = 13.3). This finding indicates that Ni-Al LDHs and not Ni-hydroxides determine the solubility of Ni in cement materials.
authors.affiliation: Waste Management Laboratory, Paul Scherrer Institute, Villigen, Switzerland. Andre.Scheidegger@psi.ch
authors.forename: A M
authors.initials: AM
authors.lastname: Scheidegger
authors.forename: E
authors.initials: E
authors.lastname: Wieland
authors.forename: A C
authors.initials: AC
authors.lastname: Scheinost
authors.forename: R
authors.initials: R
authors.lastname: Dähn
authors.forename: J
authors.initials: J
authors.lastname: Tits
authors.forename: P
authors.initials: P
authors.lastname: Spieler