Waste printed circuit boards (WPCBs) constitute a significant component of e-waste, harboring abundant recyclable valuable metals. The ongoing increase in e-waste requires an efficient recycling method to recover valuable metals, thereby enhancing the recycling efficiency. In this study, an efficient and environmentally friendly combined process of reverse flotation and two-step slurry electrolysis was used to recover copper and gold from WPCBs. In the reverse flotation process, tannic acid was conducted using as a dispersant to enhance the separation selectivity, and the recoveries of copper and gold from WPCBs reached 94.57 % and 98.01 % respectively. A new high-efficiency alkaline slurry electrolysis system with ethylenediamine (en), NH·HO, (NH)SO and Cu was devoted to recover copper from WPCBs. Under the optimal conditions, the leaching ratio, electrodeposition recovery and current efficiency of copper from WPCBs were 99.57 %, 97.53 %, and 65.64 %, respectively. Afterwards, for the anode residue after copper recovery, a kind of electrolyte consisting only of potassium iodide (KI) was proposed for recovering gold by slurry electrolysis. Under the optimal conditions, the leaching ratio, electrodeposition recovery and current efficiency of gold from WPCBs were 99.08 %, 89.12 % and 3.57 %, respectively. Thus, the copper and gold from WPCBs are recovered step by step via slurry electrolysis in different systems, it is expected to realize the application of slurry electrolysis in the e-waste industry.
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http://dx.doi.org/10.1016/j.wasman.2025.02.047 | DOI Listing |
J Environ Manage
March 2025
Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China. Electronic address:
Slurry electrolysis can be used to recover copper from waste printed circuit boards (WPCBs), but electrochemical oscillations during recovery increase the power consumption. Therefore, copper(II) chloride was selected as a simulated electrolyte to study electrochemical oscillations during the recovery of copper from WPCBs by slurry electrolysis. The results showed that a cuprous chloride passivation film formed on the cathode and induced decaying, bottom-up electrochemical oscillations whose amplitude and frequency were affected by several factors.
View Article and Find Full Text PDFWaste Manag
March 2025
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China. Electronic address:
Waste printed circuit boards (WPCBs) constitute a significant component of e-waste, harboring abundant recyclable valuable metals. The ongoing increase in e-waste requires an efficient recycling method to recover valuable metals, thereby enhancing the recycling efficiency. In this study, an efficient and environmentally friendly combined process of reverse flotation and two-step slurry electrolysis was used to recover copper and gold from WPCBs.
View Article and Find Full Text PDFBioresour Technol
February 2025
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address:
Anaerobic digestion produces substantial biogas slurry comprising abundant nutrients and complex organic matters. In this study, a process combining hydrothermal pretreatment, struvite precipitation and microbial electrolysis cells assisted anaerobic digestion (MEC-AD) was proposed to treat food waste biogas slurry, and the resource and energy recovery efficiencies were evaluated. Both hydrothermal treatment (H) and struvite precipitation (S) essentially increased CH production from 9 mL/g COD to 81.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Laboratory of Sorption Methods, Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, 119991 Moscow, Russia.
The use of reduction leaching in the production of alumina from bauxite by the Bayer process in order to decrease the amount of waste (bauxite residue) by adding elemental iron or aluminum, as well as Fe salts and organic compounds in the stage of high-pressure leaching, requires the purchase of relatively expensive reagents in large quantities. The aim of this study was to investigate the possibility of the use of electrolytically reduced bauxite residue (BR) as a substitute for these reagents. Reduced BR was obtained from Al-goethite containing BR using a bulk cathode in alkaline suspension.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
College of Chemistry and Chemical Engineering, Anshun University, Anshun, Guizhou 561000, PR China; Key Laboratory of Agricultural Resources and Environment in High Education Institute of Guizhou Province, Anshun University, Anshun, Guizhou 561000, PR China.
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