scholarly journals Development of a Physical Separation Route for the Concentration of Base Metals from Old Wasted Printed Circuit Boards

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1014
Author(s):  
Pedro Jorge Walburga Keglevich de Buzin ◽  
Weslei Monteiro Ambrós ◽  
Irineu Antônio Schadach de Brum ◽  
Rejane Maria Candiota Tubino ◽  
Carlos Hoffmann Sampaio ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Electronic Devices ◽  
Preliminary Evidence ◽  
Composition Analysis ◽  
Base Metals ◽  
Circuit Boards ◽  
Physical Separation ◽  
Printed Circuit ◽  
Processing Circuit

Wastes from old electronic devices represent a significant part of the electronic scrap generated in developing countries, being commonly sold by collectors as low-value material to recycling hubs abroad. Upgrading the quality of this waste type could drive the revenue of recyclers, and thus, boost the recycling market. On this basis, this study investigated the possibility of concentrating metals from old wasted printed circuit boards through a physical separation-based route. Preparation of samples comprised fragmentation, size classification, density, and magnetic separation steps, followed by chemical and macro composition analysis. Cu, Al, Fe, and Sn constituted the major metals encountered in the scraps, including some peak concentrations of Zn, Sb, Pb, Ba, and Mn. Four distinct concentrate products could be obtained after suitable processing: (a) a light fraction composed of plastics and resins; (b) an aluminum concentrate; (c) a magnetic material concentrate, containing mainly iron; (d) a final concentrate containing more than 50% in mass of copper and enriched with nonferrous metals. Preliminary evidence showed that further processes, like the separation of copper wires through drumming, can potentially improve the effectiveness of the proposed processing circuit and should guide future works.

Advanced Build-up Materials and Processes for Packages with Fine Line and Space

2014 ◽  
Vol 2014 (1) ◽  
pp. 000444-000447 ◽  
Author(s):  
Yoshio Nishimura ◽  
Hirohisa Narahashi ◽  
Shigeo Nakamura ◽  
Tadahiko Yokota
Keyword(s):  
Printed Circuit Boards ◽  
Coefficient Of Thermal Expansion ◽  
High Reliability ◽  
Electronic Devices ◽  
Circuit Boards ◽  
Additive Process ◽  
Fine Line ◽  
Printed Circuit ◽  
Low Dielectric ◽  
Line Space

Printed circuit boards manufactured by a semi-additive process are widely used for packaging substrates. Along with increasing demands of downsizing electronic devices with high functionality, packaging substrates installed with semiconductors in such devices are strongly required to be miniaturized with high density of circuit wirings. We report our insulation build-up materials and processes for advanced packages with fine line/space and high reliability. The insulation materials we developed show low coefficient of thermal expansion (CTE), low dielectric loss tangent and good thinner insulation reliability. They can produce fine line and space (FLS) under 10μm pitch by a semi-additive process.

Development of a versatile analytical protocol for the comprehensive determination of the elemental composition of smartphone compartments on the example of printed circuit boards

2018 ◽  
Vol 10 (31) ◽  
pp. 3864-3871 ◽  
Author(s):  
B. Bookhagen ◽  
W. Obermaier ◽  
C. Opper ◽  
C. Koeberl ◽  
T. Hofmann ◽  
...  
Keyword(s):  
Elemental Composition ◽  
Printed Circuit Boards ◽  
Electronic Devices ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Comprehensive Method ◽  
Analytical Protocol ◽  
Comprehensive Determination

A comprehensive method for the determination of metals in electronic devices was developed and tested on smartphones.

Metal Leaching Efficiency from Waste Printed Circuit Boards by Inorganic Acid

2019 ◽  
Vol 45 (3) ◽  
pp. 355-362
Author(s):  
Zhenfeng Xiong ◽  
Ying Huang ◽  
Kemei Zhou ◽  
Dong Zhang ◽  
Juan Bao ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Printed Circuit Boards ◽  
Base Metals ◽  
Circuit Boards ◽  
Aqua Regia ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Inorganic Acids ◽  
Mass Fractions ◽  
Leaching Efficiency

Waste printed circuit boards (WPCBs) from personal computers were ground and subjected to a two-step leaching process using two inorganic acids (nitric acid and aqua regia) to leach metals. Three kinds of samples were used: the whole WPCB, the golden finger part, and the WPCB excluding the golden finger. Leaching efficiencies of metals from these samples for different nitric acid concentrations (followed by aqua regia) were evaluated to identify the best concentration of nitric acid. The extracted Au concentration from the golden finger was 5.5 times of that from the whole WPCB board. Metals that compete with Au, such as Ni and Fe, have lower mass fractions in the whole WPCB board compared to those in the golden finger. However, Cu comprises a higher proportion in the golden finger. Au can be effectively separated from most other metals by initially leaching the ground WPCB with 5M nitric acid, followed by leaching with aqua regia. Considering the high leaching proportion of Au, it is advantageous to leach Au and base metals separately from the golden finger and from WPCB excluding the golden finger.

scholarly journals COPPER AND LEAD RECOVERY FROM DISCARDED PRINTED CIRCUIT BOARDS BY ELECTROLYSING LEACHED SOLUTION

2018 ◽  
Vol 55 (1B) ◽  
pp. 129
Author(s):  
Tran Thi Phuong Thao
Keyword(s):  
Printed Circuit Boards ◽  
Recovery Process ◽  
Xrd Analysis ◽  
Composition Analysis ◽  
Copper Electrodeposition ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Electrochemical Parameters ◽  
Lead Recovery ◽  
Acidic Dissolution

Results of copper and lead recovery from discarded printing circuit boards (PCB) by acidic dissolution and electrodeposition are presented. A preliminary procedure of the recovery process is proposed with the following steps: disposal of the mounted electrical elements, cleaning, grinding, iron separation for grains screening, metal dissolution, and electrolysis. The composition analysis is performed to define suitable electrochemical parameters for recovery. XRF and AAS techniques are used for preliminary estimation of metal content in leached solution. LSV method is implemented to establish parameters for copper electrodeposition. The product quality is evaluated through XRD analysis. The high recovery efficiencies, 97.61% and 96.59 % for copper (in metallic form) and lead (in dioxide form), respectively, were reached.  

scholarly journals Extraction of Selected Metals from Waste Printed Circuit Boards by Bioleaching Acidophilic Bacteria

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Anna HOŁDA ◽  
Aldona KRAWCZYKOWSKA
Keyword(s):  
Metal Content ◽  
Printed Circuit Boards ◽  
Electronic Devices ◽  
Economic Benefits ◽  
Technological Innovations ◽  
Secondary Source ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Acidophilic Bacteria ◽  
Waste Printed Circuit Boards

Technological innovations and increased demand for electronic devices resulted in production of more and more waste with highmetal content. Worldwide, 50 million tons of WEEE (Waste from Electrical and Electronic Equipment) are generated each year. Giventhe metal content present in electrical waste (e-waste), it is considered to be an urban mine and, if properly treated, can serve as analternative secondary source of metals. Waste printed circuit boards (WPCBs) that constitute approx. 3-5% of WEEE by weight areof particular importance. They contain, on average, 30-40% of metals by weight, with higher purity than in minerals. With environmental and economic benefits in mind, increasing attention is being paid to the development of processes to recover metals and othervaluable materials from WPCBs. The research presented in the article aimed at assessing the usefulness of the biotechnological methodfor leaching of selected metals from e-waste. The results indicate that it is possible to mobilize metals from WPCBs using microorganisms such as Acidithiobacillus ferroxidans bacteria 

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