title: Quantitative evaluation of environmental risks of flotation tailings from hydrothermal sulfidation-flotation process.
abstract: Floatation tailings (FT) are the main by-products of the hydrothermal sulfidation-flotation process. FT (FT1 and FT2) were obtained by treating two different neutralization sludges (NS) (NS1 and NS2). This paper quantitatively evaluated the environmental risks of heavy metals (Zn, Cd, Cu, Pb, and As) in FT versus NS. The total concentration and leaching rates (R 2) of heavy metals in FT were much lower than those in NS, demonstrating that the hydrothermal sulfidation-flotation process was able to effectively suppress the mobility and leachability of heavy metals. The BCR-three sequence leaching procedure of FT confirmed that all metals were transformed into more stable forms (residue and oxidizable forms) than were found that in NS. The potential ecological risk index indicated that the overall risks caused by heavy metals decreased significantly from 6627.59 and 7229.67 (very serious risk) in NS1 and NS2, respectively, to 80.26 and 76.27 (low risk) in FT1 and FT2, respectively. According to the risk assessment code, none of the heavy metals in FT posed significant risk to the natural environment except Zn (with low risk). In general, the risk of heavy metals in FT had been well controlled.
authors.affiliation: Institute of Environmental Science & Engineering, School of Metallurgical Science and Engineering, Central South University, 410083, Changsha, Hunan, China.
authors.forename: Xian-De
authors.initials: XD
authors.lastname: Xie
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Min
authors.forename: Li-Yuan
authors.initials: LY
authors.lastname: Chai
authors.forename: Chong-Jian
authors.initials: CJ
authors.lastname: Tang
authors.forename: Yan-Jie
authors.initials: YJ
authors.lastname: Liang
authors.forename: Mi
authors.initials: M
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Ke
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D008669:Metallurgy / Q000379:methods; D019216:Metals, Heavy / Q000737:chemistry*; D008906:Mining; D012037:Refuse Disposal / Q000379:methods*; D012307:Risk Factors; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D014867:Water