title: Evaluation on chemical stability of lead blast furnace (LBF) and imperial smelting furnace (ISF) slags.
abstract: The leaching behavior of Pb and Zn from lead blast furnace (LBF) and imperial smelting furnace (ISF) slags sampled in the North of France was studied as a function of pHs and under two atmospheres (open air and nitrogen). The leaching of major elements from the slags was monitored as a function of pH (4, 5.5, 7, 8.5 and 10) under both atmospheres for different slag-water interaction times (1 day and 9 days). The leaching results were coupled with a geochemical model; Visual MINTEQ version 3.0, and a detailed morphological and mineralogical analysis was performed on the leached slags by scanning and transmission electron microscopy (SEM and TEM). Significant amounts of Ca, Fe and Zn were released under acidic conditions (pH 4) with a decrease towards the neutral to alkaline conditions (pH 7 and 10) for both LBF and ISF slags. On the other hand, Fe leachability was limited at neutral to alkaline pH for both slags. The concentrations of all elements increased gradually after 216 h compared to initial 24 h of leaching period. The presence of oxygen under open-air atmosphere not only enhanced oxidative weathering but also encouraged formation of secondary oxide and carbonate phases. Formation of carbonates and clay minerals was suggested by Visual MINTEQ which was further confirmed by SEM & TEM. The hydration and partial dissolution of hardystonite, as well as the destabilization of amorphous glassy matrix mainly contributed to the release of major elements, whereas the spinel related oxides were resistant against pH changes and atmospheres within the time frame concerned for both LBF and ISF slags. The total amount of Pb leached out at pH 7 under both atmospheres suggested that both LBF and ISF slags are prone to weathering even at neutral environmental conditions.
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France; Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, F-75005 Paris, France; UNESCO-IHE Institute for Water Education, P.O. Box 3015, 2601 DA Delft, The Netherlands. Electronic address: yin@ipgp.fr.
authors.forename: Nang-Htay
authors.initials: NH
authors.lastname: Yin
authors.affiliation: Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, F-75005 Paris, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Sivry
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités, Muséum National d'Histoire Naturelle, UMR CNRS 7590, UPMC Univ Paris 06, IRD UMR 206, F-75005 Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Guyot
authors.affiliation: UNESCO-IHE Institute for Water Education, P.O. Box 3015, 2601 DA Delft, The Netherlands.
authors.forename: Piet N L
authors.initials: PN
authors.lastname: Lens
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France.
authors.forename: Eric D
authors.initials: ED
authors.lastname: van Hullebusch
mesh_terms: D001151:Arsenic / Q000032:analysis; D002244:Carbon / Q000032:analysis; D005591:Chemical Fractionation; D011232:Chemical Precipitation; D060729:Coal Ash / Q000032:analysis; D004784:Environmental Monitoring; D005602:France; D006863:Hydrogen-Ion Concentration; D017745:Incineration / Q000379:methods*; D007220:Industrial Waste / Q000032:analysis*; D007501:Iron / Q000032:analysis; D007854:Lead / Q000032:analysis / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D052638:Particulate Matter / Q000032:analysis / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D013232:Steel / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D015032:Zinc / Q000032:analysis / Q000737:chemistry*
chemical_list: D060729:Coal Ash; D007220:Industrial Waste; D052638:Particulate Matter; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D013232:Steel; D007854:Lead; D002244:Carbon; D007501:Iron; D015032:Zinc; D001151:Arsenic
keywords: Atmospheres; Kinetic leaching; Secondary precipitates; Slag; Weathering; pH dependent