Search Results (11)

Printed circuit boards (PCBs) are fundamental components of electronic devices, acting as an important source of various valuable metals such as copper, gold, and silver. Efficient recycling methods that offer high recovery rates are essential to the full reutilization of these materials. Hydrometallurgical leaching is a prominent technique for metal recovery, but its efficiency can be significantly enhanced through solvent pre-treatment. In this study, an experimental analysis of the material composition of different categories of PCBs is presented. In addition, the study evaluates the influence of particle size on the subsequent copper leaching process and the efficiency of copper recovery. These investigations aim to better understand the material composition of PCBs and propose an optimized material recovery technique. The study finds that there are significant variances among the different categories of PCBs investigated, allowing a more informed handling process of WEEE. This research suggests that solvent pretreatment using DMSO for PCB particle sizes between 5.6 mm and 2 mm would be a good optimization technique, mitigating the drawbacks of treating fine particles while maintaining appealing recovery efficiency. Full article

Waste from electrical and electronic equipment (WEEE) is expected to reach 82 million metric tons by 2030, with a global average of 7.8 kg/cap/year. In 2022, the amount of WEEE generated in Laos was 3.6 kg/cap/year, with no formal collection or treatment facilities in place. An examination of WEEE management and repair practices in the capital of Laos, Vientiane, was conducted, involving a review of the relevant literature and data gathered from interviews and online surveys of a total of 82 families, 17 junkshops, and 16 repair shops. Additionally, the environmental impact of smartphone repair activities was determined by utilizing data from existing life cycle assessment studies. The findings highlight the challenges of WEEE management, including infrastructure deficit and policy gaps. The informal sector plays a significant role in WEEE collection and dismantling. Manual dismantling takes place in junkshops prior to exportation to Vietnam, Thailand, and China. Reuse and repair are common practices and are present in both formal and informal contexts. Smartphone repair is a prevalent service alongside cooling and freezing equipment repair. The primary obstacles of repair are linked to the quality and availability of spare parts, the absence of repair guidelines and technical expertise, complicated designs, and consumer awareness. Notwithstanding the challenges associated with repairs, this case study demonstrates the environmental benefits of smartphone repair, achieving a reduction of 44% in GHG emissions compared to the conventional replacement over a 7-year observation period. Recommendations are proposed to enhance WEEE management systems and advance the repair movement. Full article

The demand for the use of secondary batteries is increasing rapidly worldwide in order to solve global warming and achieve carbon neutrality. Major minerals used to produce cathode materials, which are key raw materials for secondary batteries, are treated as conflict minerals due to their limited reserves, and accordingly, research on the battery recycling industry is urgent for the sustainable secondary battery industry. There is a significant risk of accidents because there is a lack of prior research data on the battery recycling process and various chemicals are used in the entire recycling process. Therefore, for the safety management of related industries, it is necessary to clearly grasp the battery recycling process and to estimate the risk accordingly. In this study, the process was generalized using the information on the battery recycling process suggested in the preceding literature. And to estimate the relative risk of each battery recycling process, the RAC (Risk Assessment Code) matrix described in the US Department of Defense’s “MIL-STD-882E” was used. Severity was derived by using “NFPA 704”, and probability was derived by combining generalized event analysis for each process and the WEEE (Waste Electrical and Electronic Equipment) report. The results confirmed that the process using H₂SO₄ had the highest risk when extracting Li during the leaching process, and that dismantling and heat treatment had the lowest risk. Using the probability factor for each process calculated through the research, it is expected to be used in future battery recycling process research as basic data for quantitative risk assessment of the battery recycling process. Full article

The amount of end-of-life electrical and electronic devices has been widely increased, globally. This emphasizes how recycling waste electric and electronic equipment (WEEE) is essential in order to reduce the amount of WEEE that is disposed of directly in the environment. Plastics account for a big percentage in WEEE, almost 20%. As a result, the application of recycling methods on plastics gathered from WEEE is of great importance since, in this way, landfill disposal can be reduced. Nevertheless, despite the advantages, there are a lot of difficulties, such as the variety of different plastics present in the plastic mix and the existence of various additives in the plastic parts, for instance, brominated flame retardants that need special attention during their treatments, which restricts their wide application. Considering all these, this review aims to provide readers with all the current techniques and perspectives that are available for both the thermal and the catalytic recycling of plastics retrieved from WEEE. Apart from the up-to-date information on the recycling methods, in this review, emphasis is also given on the advantages each method offers and also on the difficulties and the limitations that may prevent them from being applied on a large scale. Current challenges are critically examined, including the use of mechanical or thermo-chemical recycling, the treatment of individual polymers or polymer blends and the separation of harmful additives before recycling or not. Finally, emerging technologies are briefly discussed. Full article

In Part II of this series of review papers, the reaction mechanisms, thermodynamics, slag chemistry and process flowsheets are analyzed concerning cases where the TSL bath smelter has found its application. These include the primary and secondary production routes of five non-ferrous metals (tin, copper, lead, nickel, zinc), ironmaking and two waste-processing applications (spent pot lining and municipal solid waste/related ash treatment). Thereby, chemistry and processing aspects of these processes are concisely reviewed here, allowing for clear and in-depth overview of related aspects. In contrast to Part I, the focus lies on a holistic analysis of the metallurgical processes themselves, especially the particularities induced by carrying them out in a TSL reactor rather than on the respective equipment and auxiliaries. The methodology employed per metal/application is presented briefly. Firstly, the feed type and associated statistical information are introduced, along with relevant process goals, e.g., the secondary metallurgy of copper involves the recovery of platinum group metals (PGMs) from waste from electrical and electronic equipment (WEEE). Subsequently, associated chemistry is discussed, including respective chemical equations, analysis of the reaction mechanisms and phase diagrams (especially of associated slag systems); these are redrawn using FactSage 8.1 (databases used: FactPS, FToxid, FTmisc, FTsalt and FTOxCN) and validated by comparing them with the literature. Then, based on the above understanding of chemistry and thermodynamics, the flowsheets of several industrial TSL plants are introduced and discussed while providing key figures associated with process conditions and input/output streams. Finally, this article culminates by providing a concise overview of the simulation and digitization efforts on TSL technology. In light of the foregoing discourse, this paper encapsulates basic principles and operational details, specifically those pertaining to TSL bath smelting operations within the non-ferrous industry, thereby offering valuable insights intended to benefit both scholarly researchers and industry professionals. Full article

Waste electrical and electronic equipment (WEEE) presents the dual characteristic of containing both hazardous substances and valuable recoverable materials. Mainly found in WEEE plastics, brominated flame retardants (BFRs) are a component of particular interest. Several actions have been taken worldwide to regulate their use and disposal, however, in countries where no regulation is in place, the recovery of highly valuable materials has promoted the development of informal treatment facilities, with serious consequences for the environment and the health of the workers and communities involved. Hence, in this review we examine a wide spectrum of aspects related to WEEE plastic management. A search of legislation and the literature was made to determine the current legal framework by region/country. Additionally, we focused on identifying the most relevant methods of existing industrial processes for determining BFRs and their challenges. BFR occurrence and substitution by novel BFRs (NBFRs) was reviewed. An emphasis was given to review the health and environmental impacts associated with BFR/NBFR presence in waste, consumer products, and WEEE recycling facilities. Knowledge and research gaps of this topic were highlighted. Finally, the discussion on current trends and proposals to attend to this relevant issue were outlined. Full article

Informal recycling has been a source of challenges to a mobile telephone network (MTN) phone village in Rumukurushi, Port Harcourt, Nigeria, and several locations in developing countries. In order to bring a lasting solution to the menace of informal recycling in this location, the study proposed a new waste electrical and electronic equipment (WEEE) management system. The system comprises the application of two key concepts. The first concept includes limiting the activities of informal recyclers to WEEE collection only. This implies WEEE treatment, dismantling, etc., are carried out by government-approved agencies and experts. The second concept involves the application of the just-in-time (JIT) management concept for managing WEEE. The concept ensures that WEEE is only requested from the recycler or the individuals in possession of it and only on demand. The study adopted a qualitative research approach. Data collection and analysis were achieved via semi-structured phone interviews and thematic analysis, respectively. The outcome of the study limits the activities of the informal recyclers to WEEE collection. Informal recyclers gain revenue from collection. A reduction in the waiting time of workers and WEEE storage space is achieved. This offers safety, efficiency, and an increased productivity. This will help to revolutionise the WEEE management system in the location. Full article

In the transition to a circular focus on electric and electronic products, manufacturers play a key role as the originators of both the products and the information about the products. While the waste electric and electronic equipment (WEEE) directive’s contemporary focus is on handling the product as waste after its end of life, the circular economy focuses on retaining the product’s value with a restorative system. The polluter-pays principle requires producers of pollution to bear the costs of handling the pollution, leading to the extended producer responsibility (EPR) principle. This requires manufacturers to change their focus from their current passive role of out-sourcing end-of-life treatment to taking explicit responsibility for product management over an extended period of time. This paper investigates how a manufacturer can assume its responsibility to achieve circularity for its products. Based on our findings, three fundamental circularity principles, the circular electric and electronic equipment (CEEE) principles, for manufactures of electronic and electrical equipment are defined: (1) Serialize product identifiers, (2) data controlled by their authoritative source at the edge, and (3) independent actors’ access to edge data via a distributer ledger are the foundation of the Edge and Distributed Ledger (Edge&DL) model. We demonstrate the model through a case study of how to achieve circularity for lighting equipment. The CEEE principles and the demonstrated model contribute to building new circularity systems for electronic and electric products that let manufacturers undertake their extended product responsibility. Full article

Plastic materials account for about 20% of waste electrical and electronic equipment (WEEE). The recycling of this plastic fraction is a complex issue, heavily conditioned by the content of harmful additives, such as brominated flame retardants. Thus, the management and reprocessing of WEEE plastics pose environmental and human health concerns, mainly in developing countries, where informal recycling and disposal are practiced. The objective of this study was twofold. Firstly, it aimed to investigate some of the available options described in the literature for the re-use of WEEE plastic scraps in construction materials, a promising recycling route in the developing countries. Moreover, it presents an evaluation of the impact of these available end-of-life scenarios on the environment by means of the life cycle assessment (LCA) approach. In order to consider worker health and human and ecological risks, the LCA analysis focuses on ecotoxicity more than on climate change. The LCA evaluation confirmed that the plastic re-use in the construction sector has a lower toxicity impact on the environment and human health than common landfilling and incineration practices. It also shows that the unregulated handling and dismantling activities, as well as the re-use practices, contribute significantly to the impact of WEEE plastic treatments. Full article

Waste from information technology (IT) and telecommunication equipment (WITTE) constitutes a significant fraction of waste from electrical and electronic equipment (WEEE). The presence of rare metals and hazardous materials (e.g., heavy metals or flame retardants) makes the necessary recycling procedures difficult and expensive. Important efforts are being made for Waste Printed Circuit Board (WPCB) recycling because, even if they only amount to 5–10% of the WITTE weight, they constitute up to 80% of the recovered value. This paper summarizes the recycling techniques applicable to WPCBs. In the first part, dismantling and mechanical recycling techniques are presented. Within the frame of electro-mechanical separation technology, the chain process of shredding, washing, and sieving, followed by one or a combination of magnetic, eddy current, corona electrostatic, triboelectrostatic, or gravity separation techniques, is presented. The chemical and electrochemical processes are of utmost importance for the fine separation of metals coming from complex equipment such as WPCBs. Thermal recycling techniques such as pyrolysis and thermal treatment are presented as complementary solutions for achieving both an extra separation stage and thermal energy. As the recycling processes of WPCBs require adequate, efficient, and ecological recycling techniques, the aim of this survey is to identify and highlight the most important ones. Due to the high economic value of the resulting raw materials relative to the WPCBs’ weight and composition, their recycling represents both a necessary environmental protection action, as well as an economic opportunity. Full article

In the last few decades, the rapid technological evolution has led to a growing generation of waste electrical and electronic equipment (WEEE). Not rarely, it has been exported from industrialized to developing countries, where it represents a secondary source of valuable materials such as gold, copper, and silver. The recycling of WEEE is often carried out without any environmental and health protection. This paper reviews recent literature dealing with the informal treatment of WEEE in developing regions, gathering and analyzing data on concentration of both inorganic and organic pollutants in the environment. Open burning practices are revealed as most polluting ‘technology’, followed by mechanical treatment and leaching. Significant levels of pollutants have been detected in human bodies, both children and adults, working in or living in areas with informal WEEE treatment. Full article