title: Leaching and selective zinc recovery from acidic leachates of zinc metallurgical leach residues.
abstract: Zinc (Zn) leaching yields and kinetics from three different zinc plant leach residues (ZLR) generated in different periods (ZLR1>30 years, ZLR2 5-30 years and ZLR3<2 years) were investigated. The factors affecting the Zn leaching rate such as solid to liquid ratio, temperature, acid concentration and agitation were optimized. Under optimum conditions, 46.2 (±4.3), 23.3 (±2.7) and 17.6 (±1.2) mg of Zn can be extracted per gram of ZLR1, ZLR2 and ZLR3, respectively. The Zn leaching kinetics of ZLRs follow the shrinking core diffusion model. The activation energy required to leach Zn from ZLR1, ZLR2 and ZLR3 were estimated to be 2.24kcal/mol, 6.63kcal/mol and 11.7kcal/mol, respectively, by the Arrhenius equation. The order of the reaction with respect to the sulfuric acid concentration was also determined as 0.20, 0.56, and 0.87 for ZLR1, ZLR2 and ZLR3, respectively. Zn was selectively recovered from the leachates by adjusting the initial pH and by the addition of sodium hydroxide and sodium sulfide. More than 90% of Zn was selectively recovered as sphalerite from the ZLR polymetallic leachates by chemical sulfide precipitation.
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454, Marne-la-Vallée, France; UNESCO-IHE Institute for Water Education, Westvest 7, 2611, AX Delft, the Netherlands; Universidade Federal de Minas Gerais, NGqA-CPMTC, Instituto de Geociências, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
authors.forename: Manivannan
authors.initials: M
authors.lastname: Sethurajan
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454, Marne-la-Vallée, France.
authors.forename: David
authors.initials: D
authors.lastname: Huguenot
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611, AX Delft, the Netherlands.
authors.forename: Rohan
authors.initials: R
authors.lastname: Jain
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611, AX Delft, the Netherlands.
authors.forename: Piet N L
authors.initials: PN
authors.lastname: Lens
authors.affiliation: Universidade Federal de Minas Gerais, NGqA-CPMTC, Instituto de Geociências, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
authors.forename: Heinrich A
authors.initials: HA
authors.lastname: Horn
authors.affiliation: Universidade Estadual de Montes Claros, Solos e nutrição de plantas, Avenida Reinaldo Viana, 2630, Bico da Pedra-Janauba, MG 39440-000, Brazil.
authors.forename: Luiz H A
authors.initials: LH
authors.lastname: Figueiredo
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454, Marne-la-Vallée, France. Electronic address: Eric.vanHullebusch@univ-paris-est.fr.
authors.forename: Eric D
authors.initials: ED
authors.lastname: van Hullebusch
keywords: Leaching kinetics; Metal sulfide precipitation; Metallurgical wastes; Selective recovery; Shrinking core model