scholarly journals Decomposition of LCD screen inverter by pyrolysis

2019 ◽  
Vol 116 ◽  
pp. 00024
Author(s):  
Agnieszka Gurgul ◽  
Włodzimierz Szczepaniak ◽  
Monika Zabłocka-Malicka
Keyword(s):  
Printed Circuit Boards ◽  
Pyrolysis Temperature ◽  
Technology Development ◽  
Electronic Waste ◽  
Complex Structure ◽  
Circuit Boards ◽  
Gas Emission ◽  
Waste Sample ◽  
Printed Circuit ◽  
Waste Pcbs

PCBs (Printed Circuit Boards) are important parts of electronic equipment and their use increases with technology development. Recycling of waste PCBs is challenging due to their complex structure and receives wide concerns as the amount of this type of waste is growing rapidly. In the article, the experiment of pyrolysis carried out with electronic waste sample was presented. The material employed in the present work was inverter of the LCD screen that it the example of the multilayer PCB. The correlation between pyrolysis temperature and gas emission from the system, which is associated with epoxy resin decomposition, is presented in the article.

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.

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.

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.

Design and Fabrication of Riot Shield from E-Waste Printed Circuit Board

2015 ◽  
Vol 787 ◽  
pp. 18-21 ◽  
Author(s):  
A.G. Ganesh Kumar ◽  
G. Ranganath ◽  
S.N. Mani Varmaa ◽  
S. Shylin H. Jose ◽  
M. Sakthivel
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Material Strength ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Edax Analysis ◽  
Waste Printed Circuit Board ◽  
Waste Pcbs ◽  
Recycling Technique

Recycling of Printed Circuit Boards (PCB) has been carried out by powdering it into granular size of less than 10 microns. The properties of PCB reveal that it possesses density of 1.3 g/cm3 and Tensile Strength of 310 MPa which is comparatively high when compared to the Polycarbonate material which is normally used in the fabrication of Riot shield. The PCB material was subjected to SEM and EDAX analysis for determining their structure, porosity and material composition. Riot shield fabricated from PCB reduces the environmental effects of E-waste PCBs by the recycling technique, improves the material strength and reduces the weight and cost to a larger extent.

scholarly journals Resources Recovery from Electronic Waste

2020 ◽  
Author(s):  
Mohit Arora
Keyword(s):  
Nitric Acid ◽  
Printed Circuit Boards ◽  
Extraction Efficiency ◽  
Electronic Waste ◽  
Mineral Processing ◽  
Metal Recovery ◽  
Circuit Boards ◽  
Gold Extraction ◽  
Printed Circuit ◽  
Thiosulfate Leaching

Printed Circuit Boards in electronic scrap are richest source of base and precious metals, promoting economic drive for metal recovery. Recovery of these metals is a difficult exercise due to complex nature of electronic waste. India is one of the leading electronic waste processing hubs where more than 95% recyclers are unorganised/non-formal, lacking such a recovery facility. An efficient metal recovery protocol with lesser environmental impact remains unavailable to unorganised recyclers. In current study, an attempt has been made to combine various hydrometallurgical methods to achieve efficient metal recovery from Printed Circuit Boards. Mimicking mineral processing protocols for metal recovery from electronic waste has been a key feature of presented research. Printed Circuit Boards of personal computers were reduced to a size ≤ 2.5 mm and were used as sample for metal recovery. Copper and silver were extracted by selective leaching using Nitric Acid. Maximum extraction efficiency of 96.8% and 99.9% were achieved for copper and silver respectively. Nitric Acid was extracted using solvent extraction method to minimize the environmental damage of remaining waste as well as for reuse in next leaching cycle. Electrodeposition of copper was done on copper cathode with stainless steel and lead anodes with a maximum recovery efficiency of 89.6%. For extraction and recovery of gold and silver, various techniques used in mineral processing were applied in this research. Thiosulfate leaching was chosen for gold extraction due to its proven environment friendly properties. Maximum gold extraction efficiency of 74.3% has been achieved in this work. To recover gold from pregnant solution, zinc cementation approach was used. Up to 85.9% gold was recovered with zinc cementation. Success of thiosulfate leaching and cementation confirms the validity of mineralprocessing techniques in metal recovery from electronic waste. Research in this study can serve as a backbone for potential environmentally sound technology towards efficient metal recovery from electronic waste for small and medium scale recyclers.

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