title: Mineralogical determination and geo-chemical modeling of chromium release from AOD slag: Distribution and leachability aspects.
abstract: AOD (argon oxygen decarburization) slag, which is the by-product of the stainless steel refining process, is a recyclable slag because of its high content of calcium and silicon. The leaching toxicity cannot be ignored in the recycling process because the slag contains a certain amount of Cr. In this study, the mineral analysis, batch leaching tests and thermodynamic and kinetic modeling by PHREEQC combined with FactSage software were performed to explore the influence of the dissolution of primary minerals and the precipitation of secondary minerals on the elution of Cr from AOD slag. The results indicated that the main minerals in the original AOD slag are larnite, merwinite, pyroxene and periclase. Cr was dispersed in the mineral phases mentioned above. The simulation of Cr leaching controlled by Cr(III)-hydroxide corresponded better to the batch leaching tests, while the Cr leaching controlled by chromite or double control was underestimated. Increasing the L/S ratio enhances the pH of the leachate and restrains the elution of Cr from the AOD slag.
authors.affiliation: College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063009, PR China. Electronic address: 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, PR 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, PR 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, PR China.
authors.forename: Ziming
authors.initials: Z
authors.lastname: Wang
mesh_terms: D001128:Argon / Q000737:chemistry*; D002857:Chromium / Q000032:analysis / Q000737:chemistry*; D007220:Industrial Waste / Q000032:analysis; D007700:Kinetics; D008903:Minerals / Q000032:analysis / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry*; D059027:Recycling / Q000379:methods; D013193:Stainless Steel
chemical_list: D007220:Industrial Waste; D008903:Minerals; D002857:Chromium; C092478:pyroxene; D013193:Stainless Steel; D001128:Argon; D010100:Oxygen
keywords: AOD slag; FactSage; Leaching toxicity; Mineral analysis; PHREEQC