scholarly journals Leaching and Selective Recovery of Cu from Printed Circuit Boards

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1034 ◽  
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.

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

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.

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

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.

scholarly journals Analysis of the treatment of plastic from electrical and electronic waste in the Republic of Serbia and the testing of the recycling potential of non-metallic fractions of printed circuit boards

2017 ◽  
Vol 71 (3) ◽  
pp. 271-279
Author(s):  
Aleksandra Vucinic ◽  
Zeljko Kamberovic ◽  
Milisav Ranitovic ◽  
Tihomir Kovacevic ◽  
Irena Najcevic
Keyword(s):  
Chemical Composition ◽  
Printed Circuit Boards ◽  
Electronic Waste ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Mechanical Methods ◽  
The Republic ◽  
Electrical And Electronic Waste ◽  
Metallic Fractions

This paper presents the analysis of the quantity of plastic and waste printed circuit boards obtained after the mechanical treatment of electrical and electronic waste (E-waste) in the Republic of Serbia, as well as the recycling of non-metallic fractions of waste printed circuit boards. The aim is to analyze the obtained recycled material and recommendation for possible application of recyclables. The data on the quantities and treatment of plastics and printed circuit boards obtained after the mechanical treatment of WEEE, were gained through questionnaires sent to the operators who treat this type of waste. The results of the questionnaire analysis showed that in 2014 the dismantling of E-waste isolated 1,870.95 t of plastic and 499.85 t of printed circuit boards. In the Republic of Serbia, E-waste recycling is performed exclusively by using mechanical methods. Mechanical methods consist of primary crushing and separation of the materials which have a utility value as secondary raw materials, from the components and materials that have hazardous properties. Respect to that, the recycling of printed circuit boards using some of the metallurgical processes with the aim of extracting copper, precious metals and non-metallic fraction is completely absent, and the circuit boards are exported as a whole. Given the number of printed circuit boards obtained by E-waste dismantling, and the fact that from an economic point of view, hydrometallurgical methods are very suitable technological solutions in the case of a smaller capacity, there is a possibility for establishing the facilities in the Republic of Serbia for the hydrometallurgical treatment that could be used for metals extraction, and non-metallic fractions, which also have their own value. Printed circuit boards granulate obtained after the mechanical pretreatment and the selective removal of metals by hydrometallurgical processes was used for the testing of the recycling potential. Granulometric analysis as well analysis of chemical composition of obtained fractions was performed. Subsequently, the manual classification of different types of polymeric material contained in the granulate was made, and both the apparent specific gravity and the chemical composition of the classified types of polymeric materials were determined. Chemical composition of granulate was determined by X-Ray Fluorescence (XRF) using Thermo Scientific Niton XL 3t, while the identification of residual polymers was determined by the FTIR (Fourier Transform Infrared Spectroscopy) method on the Bomen MB 100 device in range 4000 to 400 cm?1. Based on the results of this study, it can be concluded that after the hydrometallurgical treatment of printed circuit boards, and the separation of metals that have the highest value, the residual non-metallic fraction have the utility value and can be used for various purposes, such as developing new polymer materials for technical purposes that have been investigated by many researchers and mentioned in this article.

scholarly journals Integrated Technological Solutions for Zero Waste Recycling of Printed Circuit Boards (PCBs)

2019 ◽  
pp. 149-169 ◽  
Author(s):  
Giacomo Copani ◽  
Marcello Colledani ◽  
Alessandro Brusaferri ◽  
Antonio Pievatolo ◽  
Eugenio Amendola ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Waste Recycling ◽  
Circuit Boards ◽  
Zero Waste ◽  
Printed Circuit

Recycling of Printed Circuit Boards by Direct Molding Technology

2019 ◽  
Author(s):  
F. Quadrini ◽  
D. Bellisario ◽  
G. M. Tedde ◽  
L. Santo
Keyword(s):  
Printed Circuit Boards ◽  
Electronic Waste ◽  
Flexural Modulus ◽  
Circuit Boards ◽  
Low Friction ◽  
Environmentally Conscious ◽  
Printed Circuit ◽  
Waste Pcbs ◽  
Pure Compression ◽  
Organic Fractions

Abstract The recovery and reuse of printed circuit boards (PCBs) is becoming crucial in the management of electronic waste that is undergoing an exponential increase. In this study, a simple and eco-friendly process for recycling waste PCBs is discussed. In particular, composite panels were produced by reusing 100% of waste PCBs without the addition of any additive or virgin material. After a two-step grinding process, ground PCB was used to mold panels by direct molding which is pure compression molding without material sorting. Results were very promising in terms of process feasibility and part performances. Molded samples had density about 1.45 g/cm3, flexural modulus and flexural about 3 GPa and 16 MPa, respectively. A smooth surface with low friction coefficient was obtained for the recycled panels. The study shows that despite the presence of metal and other non-metal non-organic fractions, waste PCBs can be re-processed in profitable and environmentally conscious way without the addition of any bonding agent or additive. The recycling technology can be extended to the reuse of the non-metallic fraction only, after separation and recovery of metals.

Isolation and characterization of copper leaching microbes from sanitary landfills for copper bioleaching of waste printed circuit boards

2021 ◽  
Author(s):  
Muhammad Syafiq Razali ◽  
Fatimah Azizah Riyadi ◽  
Fazrena Nadia Md Ak ◽  
Muhamad Ali Muhammad Yuzir ◽  
Nor’azizi Othman ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Printed Circuit Boards ◽  
Electronic Waste ◽  
Acid Leaching ◽  
Metal Extraction ◽  
Soluble Form ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Isolation And Characterization

Abstract Electronic waste has been the fastest increasing waste generated globally and predicted to surpass 111 million tons per year by the end of 2050. The amount of e-waste is a concern not just due to its volume, but also due to its high composition of heavy metal elements, which has leads to increased development of urban mining in terms of heavy metal extraction. One common method of extraction, i.e., acid leaching, is known for its harmful residual leachate, in which can have a high impact on the environment. This focuses on the alternative leaching techniques known as bioleaching, which take advantages of microbial activity in mobilization of metal into a more soluble form. Strains from sanitary landfill soil were isolated in acidic media and identified as Bacillus sp. strain SE, Lysinibacillus sp. strain SE2, Bacillus sp. strain S1A, and Oryzobacter sp. strain SC. Among the isolated stains, the identified strain Oryzobacter sp. strain SC was able to extract up to 23.36 ppm copper from waste printed circuit boards using a two-step bioleaching process, confirming the ability of the strain to perform bioleaching of copper from e-waste.

Studies on leaching characteristics of electronic waste for metal recovery using inorganic and organic acids and base

2020 ◽  
pp. 0734242X2093192
Author(s):  
Debarati Das ◽  
Siddhartha Mukherjee ◽  
Mahua Ghosh Chaudhuri
Keyword(s):  
Printed Circuit Boards ◽  
Electronic Waste ◽  
Circuit Boards ◽  
X Ray Diffraction ◽  
Aqua Regia ◽  
X Ray ◽  
Printed Circuit ◽  
Inorganic Acids ◽  
Acid And Base ◽  
Before And After

In this paper, we report leaching of precious and scattered metals such as gold (Au), copper (Cu), nickel (Ni), zinc (Zn), iron (Fe), and lead (Pb) from printed circuit boards of scrap mobile phones by hydrometallurgical process using inorganic acid, organic acid and base. The amount of metals leached by different leachants are quantified using atomic absorption spectroscopy. Among various inorganic acids, aqua regia (mixture of nitric acid (HNO3) and hydrochloric acid) is found to be the strongest leachant for most of the metals such as Zn (2.04 wt %), Fe (17.90 wt %), Ni (0.66 wt %), Pb (5.86 wt %) and Au (0.04 wt %). The basic leachant, ammonium thiosulphate is found to be very effective in leaching of Au (0.03125 wt %). The dissolution of Cu in HNO3 gives the highest amount of Cu in the solvent, that is, ∼ 7.52 wt %. The metallic phases present in the electronic waste before and after leaching are identified by X-ray diffraction analysis. The microscopic structure has been studied using a scanning electron microscope which depicts erosion of the structure after leaching.

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