Characterization of the non-metal fraction of the processed waste printed circuit boards. (May 2018)

• Record Type: Journal Article
• Authors: Kumar, Amit; Holuszko, Maria E.; Janke, Travis
• Is Part Of: Waste management. Volume 75(2018)
• Page Start: 94
• Page End: 102
• Publication Date: 2018-05
• Subjects: E-waste -- Printed circuit boards -- Non-metal fraction -- Calorific value -- Toxic characteristics leaching procedure; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2018.02.010
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: The non-metal fraction from the waste printed circuit is characterized. The TCLP test showed low level of metal leaching except for lead. The calorific value of this fraction is similar the dried wood and peat coal. The loss on ignition decreases with decrease in particle size. Abstract: Electronic waste is one the fastest growing waste streams in the world and waste printed circuit boards (PCB) are the most valuable part of this stream due to the presence of gold, silver, copper, and palladium. The metal present in PCBs is mostly recovered for the market value whereas the nonmetal fractions are often ignored. This research explored the characteristics of the non-metal fraction (NMF) obtained after the processing of milled waste PCBs with a focus on responsible end-of-life solutions, in the form of non-hazardous landfilling or incineration. The NMF was characterized using sizing, assaying, loss on ignition, calorific value measurement, and thermogravimetric analysis (TGA). The result showed that the metal content in the NMF increased with decrease in the particle size for most of the metals except antimony and the result from loss on ignition (LOI) also showed that over 50% of the coarser fraction represented organic matter compared to less than 30% for the finest fraction. The study also showed that after the recovery of metals from the waste PCBs, landfill leaching for most of the metal is reduced below the environmental limits, with lead being the only exception. The lead leachate concentration of 18 mg/L was observed, which requires further treatment prior to landfilling. With an energy value of 16 GJ/t, the NMF could provide high energy recovery if incinerated but 194 mg/kg of hazardous flame retardants present in the NMF might be released if the combustion process is not closely monitored.