Recycling Of Electronic Equipment Research Articles

Repair and Reuse or Recycle: What Is Best for Small WEEE in Australia?

The global and Australian trends indicate a steady increase in the generation of small waste electrical and electronic equipment (WEEE), constituting 30% of global WEEE in 2019 with an expected 90% increase in Australia over the next 25 years. Given this fact, identifying the most suitable circular economy strategy is vital in managing this waste stream. Hence, followed by a review of the literature, a model was developed to assess the suitability of repair, reuse, and recycling of small electrical and electronic equipment (EEE) by considering the lifespan and products put on the market (PoM) as critical variables. Findings indicate that solely repairing and reusing products, without reducing PoM small EEE, minimally affects short-term waste reduction. A synergistic approach, combining high product reuse with reduced PoM small EEE, is essential to decrease small WEEE generation significantly. Regardless of lifespan changes, the study indicates a proportional relationship between small WEEE generation rates and PoM small EEE changes, emphasising the need for a holistic strategy. Considering this, within stewardship schemes, the primary focus should initially lie on repairing and repurposing small EEE, with the potential for expansion into recycling once sufficient infrastructure and achievable recovery goals are established. Original equipment manufacturers (OEMs) must shoulder substantial accountability, with a firm commitment to extended producer responsibility (EPR) even for historical products. The initial rollout could target four specific categories: toys, food preparation equipment, vacuum cleaners, and household tools, with the scope widening to encompass all categories following successful implementation.

Technology Selection for Slag Zinc Fuming Process

Circular economy and multi-metal extraction philosophies more and more encourage smelters to reprocess their by-products most significant of which is slag for recovery of valuable metals. Zinc, for instance, can be introduced to lead and copper smelting operations through different sources, including the recycling of waste electric and electronic equipment. During the conventional smelting processes from primary resources, or even those that are particularly developed for recycling purposes, e.g., Black Copper route, the zinc is typically deported to the slag phase as zinc oxide. Recovery of zinc from slag is typically carried out via a slag zinc fuming operation, where a reductant is used to reduce zinc oxide and volatilize zinc metal. In most cases, volatilized zinc is re-oxidized to produce zinc oxide, which can then be sent to hydrometallurgical unit processes for refining. Several technologies and reactors have been developed for efficient and cost-effective fuming processes, none of which can be considered the “best” and most suitable technology for all applications and smelter conditions/slag compositions. This paper reviews the advantages and disadvantages of each of the available technologies and recommends the most suitable process for common conditions.

Shared recycling model for waste electrical and electronic equipment based on the targeted responsibility system in the context of China

The formal recycling of waste electrical and electronic equipment (WEEE) has long faced collection difficulties owing to the inadequate recycling system and insufficient collection capacity under China’s fund-based recycling model. The government has introduced the recycling Target Responsibility System (TRS) to motivate producers to develop and share recycling systems, yet without clear incentive mechanisms. In this study, we provide a “1 + N” shared recycling model referring to the theory of the sharing economy, and we propose a credit mechanism with a deposit system and a penalty mechanism for dishonesty to constrain the opportunistic behavior of sharing. In addition, according to the TRS, we design a “reduction-penalty-subsidy” fund policy to incentivize producers and recyclers to achieve recycling targets. On this basis, we apply evolutionary game theory and system dynamics approach to analyze the collaborative mechanism of shared recycling and the incentive effect of the funding policy. Game analysis yields the evolution of shared recycling from the developing stage to the mature stage. The system simulation results indicate that the government’s “penalty” and “subsidy” strategies provide evident incentives for producers and recyclers, respectively, in the developing stage, whereas endogenous dynamics derived from economies of scale under market mechanisms promote the multi-agent collaborative implementation of shared recycling in the mature stage.

Government mechanism in waste electrical and electronic equipment recycling among prospect theory and evolutionary game theory

Improper disposal of waste electrical and electronic equipment (WEEE) poses challenges for resource loss and public environmental pollution. Government policies are required to regulate WEEE recycling. To better explore the governance mechanism in the WEEE recycling network, a tripartite evolutionary game model composed of the government, recyclers, and manufacturers under bounded rationality and uncertainty was established using evolutionary game theory and prospect theory by underscoring the WEEE processing fee (WPF) exemption to adjust the behaviour of the WEEE recycling network participants. The research found that nine equilibrium points and eight possible ESSs exist and that the evolutionary stability strategies of tripartite decisions mainly depend on the trade-off between costs and revenues. Through numerical simulations, it was observed that the psychological perception of risk for recyclers and manufacturers can affect the behaviour and strategies of WEEE recycling stakeholders in uncertain environments. As WEEE recycling stakeholders increase their pursuit of safety risks, both recyclers’ and manufacturers’ willingness to engage in green behaviour is increasing. In addition, under the WPF exemption, the government can achieve the goal of encourage recyclers and manufacturers to choose green behaviour at a relatively low cost. We suggest that the government should strive to establish a stable WEEE recycling environment, establish an appropriate WPF exemption mechanism, and fully consider the cross-impact of recyclers and manufacturers to promote the green behaviour and efficiency of WEEE recycling.

Carbon Trading in China Reduces the Dependence of Household Waste Electrical and Electronic Equipment Recycling on Government Subsidies.

China's enterprises of waste electrical and electronic equipment (WEEE) recycling suffer from low profitability that is highly dependent on government subsidies. This low economic gain impedes the sustainable growth of China's WEEE-recycling sector and also adds to the government's financial burden. Prior life-cycle studies have approved the carbon reduction potentials or net carbon credit of recycling WEEE. However, policymakers fail to know whether the revenue from selling carbon credits can offset the government's financial subsidy. We performed life-cycle and cost-benefit analyses for a case recycling enterprise that processes six categories of household appliances. The results show that the reduction potentials of greenhouse gases range from 930-3450 kgCO2e by recycling per ton of household appliances and materials substitution. The recycling enterprise would gain extra revenue ranging from 32 to 160 RMB per ton of appliance if the carbon credits were sold at China's current carbon price, i.e., 45-60 RMB tCO2e-1. Recycling waste refrigerators exhibits the highest carbon revenue, offsetting 6-17% of the government's financial subsidy. Microcomputers, by contrast, indicate the lowest carbon revenue, equivalent to 1-3% of its highest government subsidy. For each household appliance category, when the carbon price reaches 270-600 RMB tCO2e-1, selling carbon credits can fully offset the government's financial subsidy. Constrained by the processing capacity of the case enterprise, optimizations for appliance-recycling composition contribute a 15-25% profit growth to the current economic gains. Interpreting the specific profit depends on the predefined scenarios of carbon price and the substitution rate of the regenerated materials for the virginal ones. Our findings show that raising the profitability of WEEE recycling enterprises through the carbon trading policy contributes to the sustainable growth of China's WEEE-recycling sector while alleviating the government's financial burden.

Experimental Study and Thermodynamic Modelling of Equilibrium Distributions of Ni, Sn and Zn Between Slag and Black Copper for E-Scrap Recycling Applications

The recycling of waste electronic and electrical equipment (WEEE) and other secondary copper-containing materials through the "black copper" process relies on the selective distribution of metals among the gas, slag, and copper-rich liquid phase. This distribution is controlled by the effective oxidation/reduction potential, often expressed in terms of oxygen partial pressure. Separation of Ni and Sn presents a certain challenge in recycling though black copper route due to similar distribution coefficients over a wide range of oxygen partial pressures and possibly can be improved by optimizing the slag chemistry. This study provides experimental information on the distribution of Ni, Sn, and Zn between fayalite slags or calcium ferrite slags and copper-rich metal at 1250°C. The study uses high-temperature equilibration, quenching, and electron probe X-ray microanalysis (EPMA) techniques along with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for selected measurements of low concentrations. The oxygen partial pressure is controlled by the CO/CO2/Ar gas flow or by measuring the concentration of copper oxide in the slag. The effect of slag composition in terms of Fe/SiO2 or Fe/CaO ratio is studied by using different holding materials, such as silica (SiO2) ampoule, solid spinel (Fe3O4), wüstite (FeO), or dicalcium ferrite (Ca2Fe2O5). The experimental results are compared with literature data and used to optimize thermodynamic models for FactSage® software. The results demonstrate an opportunity for more effective separation of Ni and Sn using at oxidizing stage by using calcium ferrite slag promoting the formation of Sn4+.

Comparison of waste photovoltaic panel processing alternatives in Australia

This work aims to compare end-of-life (EoL) alternative processing scenarios of waste photovoltaic panel in Australia. Landfill, generic waste electrical and electronic equipment recycling (European business-as-usual (EU BAU)), full-recovery EoL photovoltaic (FRELP), and Modified FRELP are the alternative processing scenarios considered for the next five years. Environmental analysis by a simplified life cycle assessment is performed using Material, Energy, Chemical, and Other (MECO) matrix. This semi-quantitative comparison eliminates reliance on LCA software and environmental expertise for preliminary screening. Financial analysis is also performed by using a life cycle costing (LCC) approach. Overall, comparative findings are consistent with full-quantitative LCA and LCC despite magnitude differences. Simplified analysis merely reflects process complexity and resource consumption. A full financial insight can only be acquired when non-resource-derived costs are incorporated. Considering the increasing trend of waste levies and landfill ban extending into the future, landfill is no longer the cheapest option in Australia. Consequently, mass-based waste recovery for landfill diversion facilitates cost savings. Recovering 8% more waste with FRELP compared to modified FRELP has the potential to save $19 more per tonne of processed PV waste. EU BAU is the most eco-efficient interim solution, while waste volume is still low. Modified FRELP saves 321 kg CO2-e emission by avoiding traditional incineration. The focus on reclaiming solar-grade silicon rather than silver has the potential to attract $154 more revenue per tonne compared to FRELP.

A novel object detection method to facilitate the recycling of waste small electrical and electronic equipment

A novel object detection method to facilitate the recycling of waste small electrical and electronic equipment

Circular Economy Management of Waste Electrical and Electronic Equipment (WEEE) in Italian Urban Systems: Comparison and Perspectives

This study evaluates the current collection and recycling of Waste Electrical and Electronic Equipment (WEEE) in Italy by means of the analysis of national and regional data from EUROSTAT and the Italian WEEE Coordination Centre database, as well as through qualitative interviews with key stakeholders of the WEEE management system of the Campania region (Southern Italy). Urban systems, among which the metropolitan city of Naples in the Campania region, are the main users of Electrical and Electronic Equipment (EEE) and, as a consequence, the main generators of WEEE, which must be managed and recovered properly in order to prevent the loss of valuable resources and the associated environmental impacts. In addition to analysing the current state of WEEE collection and recycling in Italy and its regions and urban systems, the study aims to improve our understanding of the WEEE reverse supply chain and the main barriers and drivers to collection and recycling. The results reveal that the main barriers to the collection/delivery/recycling of WEEE resulted in the low awareness of the citizens about the importance of WEEE recovery, the lack of trust towards administrators, the lack of certified first treatment plants, the aversion of the citizens to the opening of new plants due to past inefficient solutions in solid waste management, the exploitation of high value materials only (so-called “cannibalization”, the illegal trade of WEEE, the influence of the market on the valorization of secondary materials), and, finally, the dominance of economic efficiency over the proximity advantage for the disposal of solid waste. On the other hand, the main drivers for collection emerged to be the adoption of education programmes in schools and constant communication campaigns directed to citizens in order to improve WEEE collection and recycling behaviour; the adoption of economic and non-economic incentives; the availability of municipal collection points (ecological islands) and other collection centres characterised by easy access by citizens for the delivery of their WEEE.

Study on the real-time object detection approach for end-of-life battery-powered electronics in the waste of electrical and electronic equipment recycling process

With the growing use of electrical and electronic equipment (EEE), managing end-of-life EEE has become critical. Thus, the demand for sorting and detaching batteries from EEE in real time has increased. In this study, we investigated real-time object detection for sorting EEE, which using batteries, among numerous EEEs. To select products with batteries that have been mainly recycled, we crowd-sourced and gathered about 23,000 image datasets of the EEE with battery. Two learning techniques—data augmentation and transfer learning—were applied to resolve the limitations of the real-world data. We conducted YOLOv4-based experiments on the backbone and the resolution. Moreover, we defined this task as a binary classification problem; therefore, we recalculated the average precision (AP) scores from the network through postprocessing. We achieved battery-powered EEE detection scores of 90.1% and 84.5% at AP scores of 0.50 and 0.50–0.95, respectively. The results showed that this approach can provide practical and accurate information in the real world, hence encouraging the use of deep learning in the pre-sorting stage of the battery-powered EEE recycling industry.

Improving the WEEE recycling fund system in China: Multi-objective decision-making model based on EPR system

China has established a government recycling fund system based on the principle of extended producer responsibility (EPR). The principle of EPR is the key to the sustainable development of waste electrical and electronic equipment (WEEE) recycling. The implementation of the recycling fund system has been facing major problems. This article proposes a plan on refining the producer's recycling target to improve the current fund system in China. With the aim to maximize the amount of WEEE recycling, minimize the overall producer's recycling cost, and providing the best supports to the recycling industry, a multi-objective decision-making model is constructed to identify the optimum producer's recycling target for WEEE. Data from the recycling fund system and EPR pilot project of the Ministry of Industry and Information Technology are used to test the model. The results show that, under the condition that the amount of recycling is equal to the current level, the levy of recycling fund can be reduced by 20%, which can effectively drive the producers to take more responsibility in the collection and recycling of their end-of-life products. The multi-objective decision-making model for producer's recycling target provides a basis for the adjustment of China's WEEE recycling fund system policy, which will alleviate the challenge at present, and involve more producers to devote in collection systems. It also shows the alternative solution for EPR in non-fund business models in the recycling industry.

Impact of Management and Reverse Logistics on Recycling in a War Scenario

Nowadays organizations search to maximize their profits, particularly with regard to recyclable materials, making new strategies according to several emerging and changing scenarios. Logistics management is an important tool in achieving these goals, serving as a link between the market and the various areas of an organization. It is responsible for managing physical and organizational flows, both within and between organizations. Reverse logistics management of waste is one of the most complex areas in any organization, due to the financial effort needed in the separation and management of all waste, and due to the human resources allocated to those processes. The supply chain management paradigm, due to the emerging conflicts caused by war inducing extreme changes, shows that supply chains have massive difficulties and costs in obtaining raw materials, namely ferrous and non-ferrous materials. Thus, it is important to study the impact of management and reverse logistics on recycling in a “War” scenario, considering a case study from the Alto Minho region. This article’s research has the objective to raise awareness of the possible impacts of improving operations in the context of the recovery and recycling of electrical and electronic equipment through the concept of reverse logistics management. The importance of the recovery of this waste, among others, will necessarily have a great impact on logistics operation and, in particular, reverse logistics. This process includes the collection, separation, storage, reprocessing and reintroduction of electronic waste into the production chains of raw materials and components. With the crisis in production and shortages of semiconductors and raw materials, as is the case with some metals from Russia and Ukraine (exponentially aggravated by the war), this is a credible alternative. This is also relevant to the treatment of waste in landfills, transforming and converting these into biogas, which can be converted into electricity and introduced into the energy network. With this situation we obtain a triple benefit: cheaper electricity, waste treatment, and protection of future generations and the reintroduction of raw materials into production chains; these results are only possible to obtain through reverse logistics management concepts.

An Expert Decision-Making System for Identifying Development Barriers in Chinese Waste Electrical and Electronic Equipment (WEEE) Recycling Industry

Waste electrical and electronic equipment (WEEE) has become one of the fastest growing waste streams around the world, putting tremendous pressure on the environment, resources, and public health. A practically driven question about how to promote the development of the WEEE recycling industry plagues many countries, especially in developing economies such as China. This study uses an expert decision-making system based on the fuzzy Delphi technique and improved Decision-Making Trial and Evaluation Laboratory (DEMATEL) method to identify the critical barriers and their cause–effect relationships in the Chinese WEEE recycling industry. First, using the fuzzy Delphi technique, we find that nine barriers significantly impact the development of the Chinese WEEE recycling industry. Then, three critical barriers which include the implementation of policies and regulations, qualified disassembly, and unqualified disassembly are identified by employing the improved DEMATEL method. Furthermore, implementation of policies and regulations belong to the cause group, and the other two barriers belong to the effect group. Finally, some practical implications are proposed to promote the sustainable development of the Chinese WEEE recycling industry. To be specific, the Chinese government should optimize the implementation details of the e-waste take-back legislation, establish a flexible reward–supervision–penalty mechanism to support the formal collector, and improve the collection efficiency. The results of this paper are of value to firms that participate in WEEE recycling and to the government that aims to promote the sustainable development of the WEEE recycling industry.

Evolutionary game analysis of WEEE recycling tripartite stakeholders under variable subsidies and processing fees.

The standardization of formal recycling and rational subsidy plays an important role in waste electrical and electronic equipment recycling. In order to explore the tripartite decision and evolution path of waste electrical and electronic equipment recycling in different time periods, a tripartite evolutionary game model consisting of recyclers, manufacturers, and government are presented. Moreover, the evolution stability strategies and conditions in each period are calculated by replicating the dynamic equation and Jacobian matrix. Numerical simulations on tripartite evolution stability strategies corresponding to different stages of industry development are used to verify the rationality of the model. The results indicate that there is existed an indirect effect between tripartite decisions, and the indirect effect can expand the slack of tripartite decisions' thresholds of waste electrical and electronic equipment recycling. The variable subsidy in waste electrical and electronic equipment recycling proposed in this paper is useful to incentive recyclers to choose a formal recycling strategy, and manufacturers also choose production with recycled materials as subsidy varies. Besides, the appropriate waste electrical and electronic equipment processing fee is a conducive indirect effect for the tripartite decision to the optimal evolutionary stability strategy in waste electrical and electronic equipment recycling and can promote manufacturers to produce with the recycled materials. The research can assist in benefit coordination and behavior adjustment of waste electrical and electronic equipment recycling members and provide a theoretical basis for the government to formulate appropriate recycling subsidies to promote the formal recycling of electronic waste recycling.

Network Analysis of the Disaster Response Systems in the Waste of Electrical and Electronic Equipment Recycling Center in South Korea

Since dust and flammable gas are generated during the waste recycling process, there is always a risk of a fire accident. However, research on disaster management at recycling facilities deals only with the problem of processing systems from a technical standpoint and does not suggest concrete alternatives from a management aspect. Therefore, this study analyzed the influence of the disaster response network of a Waste of Electrical and Electronic Equipment (WEEE) recycling center at the organizational level based on the concept of the cognitive accuracy of a network considering administrative aspects. Accordingly, a survey was conducted using a structured questionnaire targeting 47 employees at the WEEE recycling center in South Korea and by applying the two-mode network analysis method using UCINET software, the centrality of the actor and the density of the network were quantitatively analyzed. Through this analysis, we confirmed that factors affecting the influence of the network exist, such that the entire network and the networks of different levels of position are different. We suggest that this can be improved by deploying safety and health management managers who perform formal tasks at the center of the network so that everyone can agree on the political approach and by empowering the safety and health management manager to conduct active education and training. Furthermore, we suggest that the network structure should be reorganized, centering on the person in charge of safety and health management to have a network system that matches each position.

Perspectives of Using DES-Based Systems for Solid–Liquid and Liquid–Liquid Extraction of Metals from E-Waste

In recent years, the linear economic model and global warming have shown that it is necessary to move toward a circular economic model. In this scenario, the recycling of waste electrical and electronic equipment (WEEE) with green processes is one of the pending tasks; thus, in the present review, advances in the solid–liquid and liquid–liquid extraction processes, processes among the most important for the recovery of metals from ores or WEEE, with green solvents such as deep eutectic solvents (DES) are presented and analyzed, identifying the present and future challenges. To date, most articles focused on one of the processes, be it solid–liquid or liquid–liquid extraction, while few reports included the entire hydrometallurgical process, which could be due to heterogeneity of the WEEE, a characteristic that influences determining the leaching kinetic and the leaching mechanisms. A deeper understanding of the phenomenon would help improve this process and the next stage of liquid–liquid extraction. This also leads to the fact that, at the liquid–liquid extraction stage, most articles considered synthetic pregnant leach solutions to evaluate each of the variables, whereas the stripping of the ions and the recycling of the DESs in continuous processes is a challenge that should be addressed in future work. From the analysis, for WEEE leaching, it was identified that acid DESs are those achieving the best extraction percentages in the leaching of copper, lithium, and cobalt, among others, where the most studied hydrogen bond acceptor (HBA) is choline chloride with an acid (e.g., citric or lactic acid) as the hydrogen bond donor (HBD). For the liquid–liquid extraction of ions is a greater variety of HBAs (e.g., lidocaine, trioctylphosphine oxide and triphenyl phosphate) and HBDs (e.g., decanoic acid, thenoyltrifluoroacetone, and benzoyltrifluoroacetone) used; however, studies on the extraction of cobalt, lithium, copper, and nickel stand out, where the pH and temperature parameters have great influence.

Waste Electrical and Electronic Equipment Recycling with Capacity Constraints and Demand Forecast Updating

Waste electrical and electronic equipment (WEEE) recycling plays an important role in the control of environmental pollution and sustainable use of resources. With great government incentives, third-party recycling enterprises emerge as a bridge in the formal WEEE recycle supply chain. To help the supply chain operate stably, we investigate the optimal recycle planning for the third-party recycling enterprises considering capacity constraints and demand forecast updating. A two-stage stochastic programming model is formulated. A closed-form optimal solution for the second-stage model is derived based on KKT conditions. The sampling average approximation method and genetic algorithm are combined to solve the first-stage model. A numerical study is conducted to validate the proposed model and solution.

Scaling Up the Pyrolysis Process for Integration of Shredder Light Fraction (Slf) in the Recycling of Waste Electrical and Electronic Equipment (WEEE)

Scaling Up the Pyrolysis Process for Integration of Shredder Light Fraction (Slf) in the Recycling of Waste Electrical and Electronic Equipment (WEEE)

A CNN-Based Fast Picking Method for WEEE Recycling

Recycling of Waste Electrical and Electronic Equipment (WEEE) is challenging due to the high variety in both the design and composition of the products in this waste stream. Therefore, targeted demanufacturing and appropriate material sorting processes are crucial, but remain often a manual and thus labor-intensive and costly activity. Despite first steps towards the automation of these sorting processes can be noticed, many of them are in material sorting, but very few in the sorting at product level. In this perspective, one of the key tasks is the automated classification, picking and manipulation of WEEE products.In the presented research, a closed-loop grasp planning method is proposed for the random picking of WEEE products. The presented grasping method combines a Convolutional Neural Network-based quality prediction and Closed-Loop control, named CNNB-CL, to find the optimized grasp region for unknown objects in a dense clutter. A large-scale dataset is generated for the CNN training, containing over 2.3 million synthetic grasps, and their corresponding grasp qualities evaluated by grasp simulations using 3D models. The proposed 7-layer light-weighted CNN quantitatively estimates the grasp quality of each grasp candidate. In addition, the CNNB-CL utilizes the feedback from a force-torque sensor to detect the optimized grasp and to adjust the grasp strategy. Various empirical experiments prove that the CNNB-CL method finds an optimized grasp for a WEEE clutter from 2,000 grasp candidates within 0.3 s and achieves an average success rate of 92% for different WEEE clutters. Furthermore, the average picking speed is as high as 1,400 mm/s for the random picking of small WEEE products (< 300 g) with a FANUC Delta robot (M-2i A 3SL). The fast-picking ability of the presented method reveals its potential application for the (pre-) processing of WEEE.

Urban mining of terbium, europium, and yttrium from real fluorescent lamp waste using supercritical fluid extraction: Process development and mechanistic investigation

There is a significant global push towards recycling of waste electrical and electronic equipment (WEEE) to enable the circular economy. In this study an environmentally sustainable process using supercritical carbon dioxide as the solvent, along with a small volume of tributyl-phosphate-nitric acid (TBP-HNO3) adduct as the chelating agent, is developed to extract rare earth elements (REEs) from fluorescent lamp waste. It is found that mechanical activation using oscillation milling improves extraction efficiency. To elucidate the process mechanism, an in-depth characterization of solids before and after the process using transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy (XPS)is performed. Furthermore, UV visible spectroscopy is performed to determine the coordination chemistry of the rare earths of interest, i.e., yttrium, europium, and terbium during the complexation with TBP-HNO3 adduct. It is found that Al3+ and Ca2+ cations from the aluminium oxide (Al2O3) and hydroxyapatite (Ca5(PO4)3OH) present in the fluorescent lamp waste compete with REEs in reacting with TBP-HNO3 adduct; hence, REE extractions from real fluorescent lamp waste is less than previously reported extractions from synthetic feeds. Not only can management of fluorescent lamp waste help conserve natural resources and protect ecosystems, but it can also facilitate efficient utilization of materials and promote the circular economy.