title: Dioxins reformation and destruction in secondary copper smelting fly ash under ball milling.
abstract: Secondary copper recovery is attracting increasing interest because of the growth of copper containing waste including e-waste. The pyrometallurgical treatment in smelters is widely utilized, but it is known to produce waste fluxes containing a number of toxic pollutants due to the large amount of copper involved, which catalyses the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans ("dioxins"). Dioxins are generated in secondary copper smelters on fly ash as their major source, resulting in highly contaminated residues. In order to assess the toxicity of this waste, an analysis of dioxin-like compounds was carried out. High levels were detected (79,090 ng TEQ kg(-1)) in the ash, above the Basel Convention low POPs content (15,000 ng TEQ kg(-1)) highlighting the hazardousness of this waste. Experimental tests of high energy ball milling with calcium oxide and silica were executed to assess its effectiveness to detoxify such fly ash. Mechanochemical treatment obtained 76% dioxins reduction in 4 h, but longer milling time induced a partial de novo formation of dioxins catalysed by copper. Nevertheless, after 12 h treatment the dioxin content was substantially decreased (85% reduction) and the copper, thanks to the phenomena of incorporation and amorphization that occur during milling, was almost inactivated.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory of Emerging Organic Contaminants Control (BKLEOCC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, P. R. China.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cagnetta
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory of Emerging Organic Contaminants Control (BKLEOCC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, P. R. China.
authors.forename: Mohammed Mansour
authors.initials: MM
authors.lastname: Hassan
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory of Emerging Organic Contaminants Control (BKLEOCC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory of Emerging Organic Contaminants Control (BKLEOCC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, P. R. China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory of Emerging Organic Contaminants Control (BKLEOCC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, P. R. China.|POPs Environmental Consulting, Lindenfirststrasse 23, 73527 Schwaebisch Gmuend, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Weber
mesh_terms: D000393:Air Pollutants / Q000737:chemistry; D000397:Air Pollution / Q000032:analysis / Q000517:prevention & control; D000465:Algorithms; D017610:Calcium Compounds / Q000737:chemistry; D002384:Catalysis; D060729:Coal Ash / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D000072338:Dibenzofurans, Polychlorinated / Q000737:chemistry; D004147:Dioxins / Q000737:chemistry*; D055595:Mechanical Phenomena; D008669:Metallurgy; D008956:Models, Chemical; D010087:Oxides / Q000737:chemistry; D000072317:Polychlorinated Dibenzodioxins / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D017610:Calcium Compounds; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins; D010087:Oxides; D000072317:Polychlorinated Dibenzodioxins; D012822:Silicon Dioxide; D003300:Copper; C016538:lime