title: Acid extraction of molybdenum, nickel and cobalt from mineral sludge generated by rainfall water at a metal recycling plant.
abstract: This study investigated the leaching yields of Mo, Ni and Co from a mineral sludge of a metal recycling plant generated by rainfalls. The investigated mineral sludge had a complex heterogeneous composition, consisting of particles of settled soil combined with metal-bearing particles (produced by catalysts, metallic oxides and battery recycling). The leaching potential of different leaching reagents (stand-alone strong acids (HNO3 (68%), H2SO4 (98%) and HCl (36%)) and acid mixtures (aqua regia (nitric + hydrochloric (1:3)), nitric + sulphuric (1:1) and nitric + sulphuric + hydrochloric (2:1:1)) was investigated at changing operational parameters (solid-liquid (S/L) ratio, leaching time and temperature), in order to select the leaching reagent which achieves the highest metal leaching yields. Sulphuric acid (98% H2SO4) was found to be the leachant with the highest metal leaching potential. The optimal leaching conditions were a three-stage successive leaching at 80 °C with a leaching time of 2 h and S/L ratio of 0.25 g L(-1). Under these conditions, the achieved mineral sludge sample leaching yields were 85.5%, 40.5% and 93.8% for Mo, Ni and Co, respectively. The higher metal leaching potential of H2SO4 in comparison with the other strong acids/acid mixtures is attributed to the fact that H2SO4 is a diacidic compound, thus it has more H(+) ions, resulting in its stronger oxidizing power and corrosiveness.
authors.affiliation: a Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est , EA 4508, UPEM, 77454 Marne-la-Vallée , France.|b Faculté des Sciences & Techniques , Université de Limoges, Groupement de Recherche Eau-Sol-Environnement (GRESE) , 123 avenue Albert Thomas, 87060 Limoges , France.|c UNESCO-IHE Institute for Water Education , Westvest 7, 2611 AX Delft , The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Vemic
authors.affiliation: b Faculté des Sciences & Techniques , Université de Limoges, Groupement de Recherche Eau-Sol-Environnement (GRESE) , 123 avenue Albert Thomas, 87060 Limoges , France.
authors.forename: F
authors.initials: F
authors.lastname: Bordas
authors.affiliation: b Faculté des Sciences & Techniques , Université de Limoges, Groupement de Recherche Eau-Sol-Environnement (GRESE) , 123 avenue Albert Thomas, 87060 Limoges , France.
authors.forename: G
authors.initials: G
authors.lastname: Guibaud
authors.affiliation: d ERAMET, Avenue Maryse Bastié , 87410 Le Palais sur Vienne , France.
authors.forename: S
authors.initials: S
authors.lastname: Comte
authors.affiliation: b Faculté des Sciences & Techniques , Université de Limoges, Groupement de Recherche Eau-Sol-Environnement (GRESE) , 123 avenue Albert Thomas, 87060 Limoges , France.
authors.forename: E
authors.initials: E
authors.lastname: Joussein
authors.affiliation: c UNESCO-IHE Institute for Water Education , Westvest 7, 2611 AX Delft , The Netherlands.
authors.forename: P N L
authors.initials: PN
authors.lastname: Lens
authors.affiliation: a Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est , EA 4508, UPEM, 77454 Marne-la-Vallée , France.
authors.forename: E D
authors.initials: ED
authors.lastname: Van Hullebusch
mesh_terms: D000143:Acids / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D008982:Molybdenum / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D011891:Rain / Q000737:chemistry; D059027:Recycling / Q000379:methods*
chemical_list: D000143:Acids; D003035:Cobalt; D009532:Nickel; D008982:Molybdenum
keywords: Mineral sludge; chemical leaching; leaching yields; metals; sulphuric acid