Environmental Impact Assessment of Hydrometallurgical Processes for Metal Recovery from WEEE Residues Using a Portable Prototype Plant

Abstract

Life cycle assessment (LCA) was applied to hydrometallurgical treatments carried out using a new portable prototype plant for the recovery of valuable metals from waste electrical and electronic equipment (WEEE). The plant was fed with the WEEE residues from physical processes for the recycling of fluorescent lamps, cathode ray tubes (CRTs), Li-ion accumulators and printed circuit boards (PCBs). Leaching with sulfuric acid was carried out, followed by metal recovery by selective precipitation. A final step of wastewater treatment with lime was performed. The recovered metals included yttrium, zinc, cobalt, lithium, copper, gold, and silver. The category of global warming potential was the most critical one considering the specifications for southern European territories, with 13.3 kg CO(2)/kg recovered metal from the powders/residues from fluorescent lamps, 19.2 kg CO(2)/kg from CRTs, 27.0 kg CO(2)/kg from Li-ion accumulators and 25.9 kg CO(2)/kg from PCBs. Data also show that metal extraction steps have the highest load for the environment. In general, these processes appear beneficial for the environment in terms of CO(2) emissions, especially for metal recovery from WEEE residues from fluorescent lamps and CRTs.

Challenges in Waste Electrical and Electronic Equipment Management: A Profitability Assessment in Three European Countries

“…The presented results are in line with the ones described by the experts within the scientific literature [25,35,37,45]. However, it is important to point out that a direct comparison with the results coming from the literature is not possible due to two reasons.…”

“…However, the same economic principles can be used to also assess other refining methods, without twisting the overall value of the work. Hydrometallurgy is the optimal choice to implement field and mobile plants, given both its high sustainability level in comparison to other metal refining methods and the flexibility level of related plants [35][36][37].…”

Solving e-waste problem using an integrated mobile recycling plant

“…Management of this waste has been recognized as a global challenge. Many developing countries have not significantly changed their course with regard to e-waste contamination (Fujimori et al, 2012), and they are still the specter of mountains of hazardous e-waste, with serious consequences for both the ecological environment and public health (Song and Li, 2014). For instance in China, e-wastes have become an important waste stream (over 2.3 million tonnes annually), both in terms of quantity and toxicity (Qu et al, 2013).…”

A Review of the Carbon Footprint of Cu and Zn Production from Primary and Secondary Sources

“…Figure 5 presents the CFs of Zn production from secondary sources grouped by source material. Available information about CF is mostly related to Zn recovery from scrap and fly ash produced after municipal solid waste (MSW) incineration, while only a few papers are available for the production of Zn from waste electrical and electronic equipment (WEEE) [45]. Boesch and co-workers [39] investigated the recovery of Zn from MSW fly ash considering combustion in a grate incinerator, the use and recovery from slag and fly ash, and the landfilling of residues.…”

“…The recovered metals included Y, Zn, Co, Li, Cu, Au, and Ag. In the case of Zn, which is contained in CRTs (30-35% Zn, as oxide and sulfur compound), an estimated CF of 5.5 kg CO 2 -eq/kg Zn was calculated [45]. Concerning Zn production from steel dust, only one paper has been found, while the CF analysis does not provide specific information [52].…”