title: An alternative approach to recovering valuable metals from zinc phosphating sludge.
abstract: This study used a vitrification process (with good potential for commercialization) to recover valuable metals from Zn phosphating sludge. The involved vitrification process achieves two major goals: it transformed hazardous Zn phosphating sludge into inert slag and it concentrated Fe (83.5%) and Zn (92.8%) into ingot and fine particulate-phase material, respectively. The Fe content in the ingot was 278,000 mg/kg, making the ingot a potential raw material for iron making. The fine particulate-phase material (collected from flue gas) contained abundant Zn (544,000 mg/kg) in the form of ZnO. The content (67.7%) of ZnO was high, so it can be directly sold to refineries. The recovered coarse particulate-phase material, with insufficient amount of ZnO, can be recycled as a feeding material for Zn re-concentration. Therefore, the vitrification process can not only treat hazardous materials but also effectively recover valuable metals.
authors.affiliation: Department of Safety Health and Environmental Engineering, Chung Hwa University of Medical Technology, Tainan City 71703, Taiwan, ROC. yiming@mail.hwai.edu.tw
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Kuo
mesh_terms: D006256:Hazardous Waste / Q000517:prevention & control*; D007220:Industrial Waste / Q000517:prevention & control*; D007501:Iron / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D010710:Phosphates / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D015032:Zinc / Q000302:isolation & purification*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D006256:Hazardous Waste; D007220:Industrial Waste; D010710:Phosphates; D012722:Sewage; D017967:Zinc Compounds; C043952:zinc phosphate; D007501:Iron; D015032:Zinc