The present study reports a mechanochemical (MC) process for effective recovery of copper (Cu) and precious metals (i.e. Pd and Ag) from e-waste scraps. Results indicated that the mixture of KSO and NaCl (abbreviated as KSO/NaCl hereafter) was the most effective co-milling reagents in terms of high recovery rate. After co-milling with KSO/NaCl, soluble metallic compounds were produced and consequently benefit the subsequent leaching process. 99.9% of Cu and 95.5% of Pd in the e-waste particles could be recovered in 0.5mol/L diluted HCl in 15min. Ag was concentrated in the leaching residue as AgCl and then recovered in 1mol/L NH solution. XRD and XPS analysis indicated that elemental metals in the raw materials were transformed into their corresponding oxidation state during ball milling process at low temperature, implying that solid-solid phase reactions is the reaction mechanism. Based on the results and thermodynamic parameters of the probable reactions, possible reaction pathways during ball milling were proposed. Suggestion on category of e-waste for ball milling process was put forward according to the experiment results. The designed metal recovery process of this study has the advantages of highly recovery rate and quick leaching speed. Thus, this study offers a promising and environmentally friendly method for recovering valuable metals from e-waste.
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http://dx.doi.org/10.1016/j.wasman.2017.07.029 | DOI Listing |
Environ Sci Technol
January 2025
Department of Civil and Environmental Engineering, Clarkson University, Potsdam, New York 13699, United States.
The nonthermal destruction of aqueous film-forming foam (AFFF) stockpiles, one of the major culprits responsible for water and soil contamination by per- and polyfluoroalkyl substances (PFAS), is extremely challenging because of the coexistence of mixed recalcitrant PFAS and complicated organic matrices at extremely high concentrations. To date, the complete defluorination of undiluted AFFF at ambient conditions has not been demonstrated. This study reports a novel piezoelectric ball milling approach for treating AFFF with a total organic fluorine concentration of 9080 mg/L and total organic carbon of 234 g/L.
View Article and Find Full Text PDFChemistry
January 2025
Henan Normal University, School of Chemistry and Chemical Engineering, CHINA.
Currently, the development of suitable transition metal chalcogenides (TMDs) for aqueous zinc ion batteries (AZIBs) is plagued by the terrible conductivity and electrochemical properties. Herein, a one-step ball milling method is applied to enhance the conductivity of commercial MnTe cathode by constructing three dimensional (3D) carbon nanotubes (CNTs) interweaved MnTe nanoparticles (abbreviated as MnTe@CNTs), which can achieve ultrafast ion conduction. The stable electrochemistry properties benefit from the synergistic effects between layered MnTe and 3D CNTs, which can improve the electrons/ions diffusion kinetics as cycling.
View Article and Find Full Text PDFiScience
January 2025
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
Developing high-performance alloys is essential for applications in advanced electromagnetic energy conversion devices. In this study, we assess Fe-Co-Ni alloy compositions identified in our previous work through a machine learning (ML) framework, which used both multi-property ML models and multi-objective Bayesian optimization to design compositions with predicted high values of saturation magnetization, Curie temperature, and Vickers hardness. Experimental validation was conducted on two promising compositions synthesized using three different methods: arc melting, ball milling followed by spark plasma sintering (SPS), and chemical synthesis followed by SPS.
View Article and Find Full Text PDFHeliyon
January 2025
Centre for functional and surface functionalized glass, Alexander Dubček University of Trenčín, Študentská 2, Trenčín, Slovakia.
The impact of grinding on particle size, thermal behaviour, and sintering ability of yttrium aluminate glass microspheres with eutectic composition (76.8 mol % AlO and 23.2 mol % YO) was studied.
View Article and Find Full Text PDFChemSusChem
January 2025
Polish Academy of Sciences, Institute of Organic Chemistry, Kasprzaka 44/52, 01-224, Warsaw, POLAND.
We demonstrate the application of mechanochemistry in the synthesis of indolone-based photoswitches (hemiindigos, hemithioindigos, and oxindoles) via Knoevenagel condensation reactions. Utilizing ball-milling and an organic base (piperidine) acting as catalyst and solvent for liquid assisted grinding (LAG) conditions, we achieve rapid, solvent-free transformations, obtaining a set of known and previously unreported photoswitches, including highly functional amino acid-based photoswitches, multichromophoric derivatives and photoswitchable cavitands based on resorcin[4]arenes. The reaction under mechanochemical conditions gives moderate-to-high yields and is highly stereoselective leading to Z-isomers of hemiindigos and hemithioindigos and E-isomers of oxindoles.
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