Experimental Stand for Sorting Components Dismantled from Printed Circuit Boards

There is nothing new about the fact that higher concentrations (up to 50 times) of valuable materials can be found in e-waste, compared to mined ores. Moreover, the constant accumulation of excessive amounts of waste equipment has a negative impact on the environment. The components found in electronic equipment may contain hazardous materials or materials that could be recycled and reintroduced into production processes, thus reducing the carbon footprint created by waste electrical and electronics equipment (WEEE). Sustainable e-waste recycling requires high-value, integrated recovery systems. By implementing a two-stage experimental sorting stand, this paper proposes an efficient and fast sorting method that can be industrially scaled up to reduce the time, energy and costs needed to sort electronic waste (e-waste). The sorting equipment is in fact an ensemble of sensors consisting of cameras, color sensors, proximity sensors, metal detectors and a hyperspectral camera. The first stage of the system sorts the components based on the materials’ spectral signature by using hyperspectral image (HSI) processing and, with the help of a robotic arm, removes the marked components from the conveyor belt. The second stage of the sorting stand uses a contour vision camera to detect specific shapes of the components to be sorted with the help of pneumatic actuators. The experimental sorting stand is able to distinguish up to five types of components with an efficiency of 89%.

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Determinants of Residents’ E-Waste Recycling Behavioral Intention: A Case Study from Vietnam

Sustainability ◽

10.3390/su11010164 ◽

2018 ◽

Vol 11 (1) ◽

pp. 164 ◽

Cited By ~ 14

Author(s):

Hong Thi Thu Nguyen ◽

Rern-Jay Hung ◽

Chun-Hung Lee ◽

Hang Thi Thu Nguyen

Keyword(s):

Behavioral Intention ◽

Management System ◽

Structural Equation ◽

Negative Impact ◽

Electronic Waste ◽

Waste Recycling ◽

Equation Modeling ◽

Policy Makers ◽

Negative Effect ◽

Laws And Regulations

An enormous volume of electronic waste (e-waste) is currently being generated in Vietnam, threatening to render this country as an e-waste dumping region. Although the residents play an indispensable role in the e-waste management system, there is presently no or very limited studies available which involve public perceptions on the e-waste recycling in Vietnam. In this study, based on the theory of planned behavior (TPB), the structural equation modeling (SEM) was employed to examine the key factors influencing e-waste recycling behavioral intention of residents in Danang city, Vietnam. Data analyzed from 520 questionnaires revealed that environmental awareness and attitude toward recycling, social pressure, laws and regulations, cost of recycling, and inconvenience of recycling significantly directly affected residents’ behavioral intention, with laws and regulations being the strongest construct significantly to predict individuals’ intention. Of the five above-listed constructs, only inconvenience of recycling had a negative impact on residents’ recycling behavioral intention. Moreover, past experience showed the statistically significant negative effect on the inconvenience of recycling while it had no significant impact on behavioral intention. The influences of demographic variables on recycling behavioral intention were also discussed in this paper. The findings from this research may help policy-makers have a better understanding of residents’ e-waste recycling intention. That is very useful in paving the way for a successful e-waste recycling and management system not only in Vietnam, but also in other countries which are suffering from the same problems of e-waste.

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Recovery of Metals from Printed Circuit Boards By Means of Electrostatic Separation

Management Systems in Production Engineering ◽

10.2478/mspe-2020-0031 ◽

2020 ◽

Vol 28 (4) ◽

pp. 213-219

Author(s):

Dawid Franke ◽

Tomasz Suponik ◽

Paweł M. Nuckowski ◽

Klaudiusz Gołombek ◽

Kamila Hyra

Keyword(s):

Waste Management ◽

Printed Circuit Boards ◽

Printed Circuit Board ◽

New Technologies ◽

Negative Impact ◽

Electronic Waste ◽

Circuit Board ◽

Circuit Boards ◽

Electrostatic Separation ◽

Printed Circuit

AbstractWithout the use of appropriate recycling technologies, the growing amount of electronic waste in the world can be a threat to the development of new technologies, and in the case of improper waste management, may have a negative impact on the environment. This is due to the fact that this waste contains large amounts of valuable metals and toxic polymers. Therefore, it should be recycled in accordance with the assumptions of the circular economy. The methods of mechanical recovery of metals from electronic waste, including printed circuits, may be widely used in the future by waste management companies as well as metal production and processing companies. That is why, a well-known and easily applicable electrostatic separation (ES) method was used to recover metals from printed circuit boards. The grain class of 0.32 - 0.10 mm, obtained after grinding the boards, was fed to a separator. Feed and separation products were analyzed by means of ICP-AES, SEM/EDS and XRD. The concentrate yield obtained after electrostatic separation amounted to 32.3% of the feed. Its density was 11.1 g/cc. Out of the 91.44% elements identified in the concentrate, over 90% were metals. XRD, SEM observations and EDS analysis confirmed the presence of non-metallic materials in the concentrate. This relatively high content of impurities indicates the need to grind printed circuit board into grain classes smaller than 0.32-0.10 mm.

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Recovery of base and precious metals from PCBs (Printed Circuit Boards) in waste electrical and electronic equipment (WEEE)

World Journal of Advanced Research and Reviews ◽

10.30574/wjarr.2022.13.1.0734 ◽

2022 ◽

Vol 13 (1) ◽

pp. 001-011

Author(s):

Yete Pélagie ◽

Togbe FC Alexis ◽

Yovo Franck ◽

Suanon Fidèle ◽

Sidohounde Assou ◽

...

Keyword(s):

Printed Circuit Boards ◽

Electronic Waste ◽

Precious Metals ◽

Developed Countries ◽

Waste Recycling ◽

Electronic Equipment ◽

Circuit Boards ◽

African Countries ◽

Printed Circuit ◽

Advantages And Disadvantages

Natural minerals are a powerful tool in politics when some have a major role in production. Its depletion is now a hot topic worldwide. Thus, the safety of the environment, natural surface water, groundwater and the protection of soils from chronic contamination by metallic and inorganic elements is a global concern. Indeed, industrialization and development have led to the generation of huge and varied amounts of waste, including electronic waste (e-waste), which is released into the environment. Although e-waste is classified as hazardous, most of it is not recycled and developed countries with strict environmental protection legislation send most of their e-waste to developing countries where regulations are lax. These electronic devices and components after being used are simply dumped into the environment due to lack of treatment and recycling strategy. As a result, they become a threat to the environment, ecosystems and humans. African countries are among the most vulnerable nations. But they are unfortunately ignored and underestimated. To date, there is no e-waste recycling unit (factory) in most African countries and mainly in the Republic of Benin. In response to this challenge, this study explored the different techniques used for the recycling of waste electrical/electronic equipment in order to develop a new environmentally friendly approach in future work, for the extraction and recycling of the usual and valuable metallic elements contained in electronic waste (printed circuit boards) released into the environment. For this purpose, a bibliographic research was carried out from 20 April to 16 October 2021. The results obtained allowed us to identify the advantages and disadvantages of existing recycling methods.

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Leaching and Selective Recovery of Cu from Printed Circuit Boards

Metals ◽

10.3390/met9101034 ◽

2019 ◽

Vol 9 (10) ◽

pp. 1034 ◽

Cited By ~ 7

Author(s):

Manivannan Sethurajan ◽

Eric D. van Hullebusch

Keyword(s):

Copper Sulfide ◽

Printed Circuit Boards ◽

Electronic Waste ◽

Waste Recycling ◽

Ferric Sulfate ◽

Molar Ratio ◽

Circuit Boards ◽

Optimum Conditions ◽

Selective Recovery ◽

Printed Circuit

Printed circuit boards (PCBs), a typical end-of-life electronic waste, were collected from an E-waste recycling company located in the Netherlands. Cu and precious metal concentration analyses of the powdered PCBs confirm that the PCBs are multimetallic in nature, rich, but contain high concentrations of Cu, Au, Ag, Pd, and Pt. Ferric sulfate concentration (100 mM), agitation speed (300 rpm), temperature (20 °C), and solid-to-liquid ratio (10 g·L−1) were found to be the optimum conditions for the maximum leaching of Cu from PCBs. The ferric sulfate leachates were further examined for selective recovery of Cu as copper sulfides. The important process variables of sulfide precipitation, such as lixiviant concentration and sulfide dosage were investigated and optimized 100 ppm of ferric sulfate and (copper:sulfide) 1:3 molar ratio, respectively. Over 95% of the dissolved Cu (from the multimetallic leachates) was selectively precipitated as copper sulfide under optimum conditions. The characterization of the copper sulfide precipitates by SEM-EDS analyses showed that the precipitates mainly consist of Cu and S. PCBs can thus be seen as a potential secondary resource for copper.

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Study of non-linear synergy control laws on the experimental stand of pneumatic actuators

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1029/1/012018 ◽

2021 ◽

Vol 1029 ◽

pp. 012018

Author(s):

E Obukhova

Keyword(s):

Control Laws ◽

Pneumatic Actuators ◽

Experimental Stand ◽

Non Linear

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Brominated flame retardants (BFRs) in PM2.5 associated with various source sectors in southern China

Environmental Science Processes & Impacts ◽

10.1039/d0em00443j ◽

2021 ◽

Author(s):

qiqi li ◽

Tao Wang ◽

yuan zeng ◽

yun fan ◽

Shejun Chen ◽

...

Keyword(s):

Flame Retardants ◽

Southern China ◽

Electronic Waste ◽

Brominated Flame Retardants ◽

Waste Recycling ◽

Recycling Facilities

The present study investigated legacy and novel brominated flame retardants (BFRs) in atmospheric PM2.5 associated with various urban source sectors in a city and electronic waste (e-waste) recycling facilities in...

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Food Waste-Assisted Metal Extraction from Printed Circuit Boards: The Aspergillus niger Route

Microorganisms ◽

10.3390/microorganisms9050895 ◽

2021 ◽

Vol 9 (5) ◽

pp. 895

Author(s):

Carlotta Alias ◽

Daniela Bulgari ◽

Fabjola Bilo ◽

Laura Borgese ◽

Alessandra Gianoncelli ◽

...

Keyword(s):

Solid State ◽

Aspergillus Niger ◽

Food Waste ◽

Solid State Fermentation ◽

Printed Circuit Boards ◽

Electronic Waste ◽

Metal Extraction ◽

Circuit Boards ◽

Printed Circuit ◽

Waste Printed Circuit Boards

A low-energy paradigm was adopted for sustainable, affordable, and effective urban waste valorization. Here a new, eco-designed, solid-state fermentation process is presented to obtain some useful bio-products by recycling of different wastes. Urban food waste and scraps from trimmings were used as a substrate for the production of citric acid (CA) by solid state fermentation of Aspergillus niger NRRL 334, with a yield of 20.50 mg of CA per gram of substrate. The acid solution was used to extract metals from waste printed circuit boards (WPCBs), one of the most common electronic waste. The leaching activity of the biological solution is comparable to a commercial CA one. Sn and Fe were the most leached metals (404.09 and 67.99 mg/L, respectively), followed by Ni and Zn (4.55 and 1.92 mg/L) without any pre-treatments as usually performed. Commercial CA extracted Fe more efficiently than the organic one (123.46 vs. 67.99 mg/L); vice versa, biological organic CA recovered Ni better than commercial CA (4.55 vs. 1.54 mg/L). This is the first approach that allows the extraction of metals from WPCBs through CA produced by A. niger directly grown on waste material without any sugar supplement. This “green” process could be an alternative for the recovery of valuable metals such as Fe, Pb, and Ni from electronic waste.

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Estimating Recycling Return of Integrated Circuits Using Computer Vision on Printed Circuit Boards

Applied Sciences ◽

10.3390/app11062808 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2808

Author(s):

Leandro H. de S. Silva ◽

Agostinho A. F. Júnior ◽

George O. A. Azevedo ◽

Sergio C. Oliveira ◽

Bruno J. T. Fernandes

Keyword(s):

Integrated Circuits ◽

Printed Circuit Boards ◽

Printed Circuit Board ◽

Electronic Waste ◽

Decision Criterion ◽

Economic Feasibility ◽

Electronic Equipment ◽

Circuit Board ◽

Mechanical Recycling ◽

Printed Circuit

The technological growth of the last decades has brought many improvements in daily life, but also concerns on how to deal with electronic waste. Electrical and electronic equipment waste is the fastest-growing rate in the industrialized world. One of the elements of electronic equipment is the printed circuit board (PCB) and almost every electronic equipment has a PCB inside it. While waste PCB (WPCB) recycling may result in the recovery of potentially precious materials and the reuse of some components, it is a challenging task because its composition diversity requires a cautious pre-processing stage to achieve optimal recycling outcomes. Our research focused on proposing a method to evaluate the economic feasibility of recycling integrated circuits (ICs) from WPCB. The proposed method can help decide whether to dismantle a separate WPCB before the physical or mechanical recycling process and consists of estimating the IC area from a WPCB, calculating the IC’s weight using surface density, and estimating how much metal can be recovered by recycling those ICs. To estimate the IC area in a WPCB, we used a state-of-the-art object detection deep learning model (YOLO) and the PCB DSLR image dataset to detect the WPCB’s ICs. Regarding IC detection, the best result was obtained with the partitioned analysis of each image through a sliding window, thus creating new images of smaller dimensions, reaching 86.77% mAP. As a final result, we estimate that the Deep PCB Dataset has a total of 1079.18 g of ICs, from which it would be possible to recover at least 909.94 g of metals and silicon elements from all WPCBs’ ICs. Since there is a high variability in the compositions of WPCBs, it is possible to calculate the gross income for each WPCB and use it as a decision criterion for the type of pre-processing.

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