title: Maximum availability and mineralogical control of chromium released from AOD slag.
abstract: AOD (argon oxygen decarburization) slag is the by-product in the stainless steel refining process. Chromium existing in AOD slag can leach out and probably poses a serious threat to the environment. To assess the leaching toxicity of chromium released from AOD slag, the temperature-dependent maximum availability leaching test was performed. To determine the controlling mineralogical phases of chromium released from AOD slag, a Visual MINTEQ simulation was established based on Vminteq30 and the FactSage 7.0 database. The leaching tests indicated that the leaching availability of chromium was slight and mainly consisted of trivalent chromium. Aging of AOD slag under the atmosphere can oxidize trivalent chromium to hexavalent chromium, which could be leached out by rainwater. According to the simulation, the chromium concentration in leachates was controlled by the freely soluble pseudo-binary phases in the pH = 7.0 leaching process and controlled by the Cr2O3phase in the pH = 4.0 leaching process. Chromium concentrations were underestimated when the controlling phases were determined to be FeCr2O4and MgCr2O4. Facilitating the generation of the insoluble spinel-like phases during the cooling and disposal process of the molten slag could be an effective approach to decreasing the leaching concentration of chromium and its environmental risk.
authors.affiliation: College of Metallurgy and Energy, North China University of Science and Technology, Tangshan, 063009, People's Republic of China. lijg99@163.com.
authors.forename: Junguo
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Metallurgy and Energy, North China University of Science and Technology, Tangshan, 063009, People's Republic of China.
authors.forename: Bao
authors.initials: B
authors.lastname: Liu
authors.affiliation: College of Metallurgy and Energy, North China University of Science and Technology, Tangshan, 063009, People's Republic of China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: College of Metallurgy and Energy, North China University of Science and Technology, Tangshan, 063009, People's Republic of China.
authors.forename: Ziming
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Metallurgy and Energy, North China University of Science and Technology, Tangshan, 063009, People's Republic of China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Gao
mesh_terms: D001128:Argon / Q000737:chemistry; D001272:Atmosphere; D002857:Chromium / Q000032:analysis*; D004784:Environmental Monitoring; D010100:Oxygen / Q000032:analysis; D013193:Stainless Steel / Q000032:analysis*
chemical_list: D002857:Chromium; D013193:Stainless Steel; C074702:chromium hexavalent ion; D001128:Argon; D010100:Oxygen
keywords: AOD slag; Chromium; Geochemical model; Maximum availability; Mineralogical control