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 

Study on Wet Treatment Process of Waste Printed Circuit Boards

2012 ◽  
Vol 518-523 ◽  
pp. 3621-3626
Author(s):  
Cai Bin Wu ◽  
Gui Ming Shi ◽  
Cui Ping Yan
Keyword(s):  
Metal Content ◽  
Printed Circuit Boards ◽  
Treatment Process ◽  
Shaking Table ◽  
Circuit Boards ◽  
Total Metal Content ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Total Metal ◽  
Comminution Process

The dry crushing of wasted printed circuit boards (PCBs) can make secondary contamination. In this paper, a wet comminution process is put forward to solve the difficulties. For the comminution product, the distributions of particle size, liberation degree and metal grade are analyzed, and for the product below 1mm, a wet metal beneficiation process combined with shaking table and flotation is employed. The results show that the Whole PCBs could be comminuted by the MX wet impact crusher, and the cumulative yield, liberation degree, total metal content and its copper grade of the product below 1mm is 83.49%, 97%, 83.46% and 20.50%respectively, and that metal concentrates could be beneficiated by XZY wet shaking table, and the yield, total metal weight, copper grade of the metal concentrate, the recovery of total metal and copper is 34.87%, 88.99%, 50.73%,79.90% and 78.07% respectively keeping the feeding concentration at 20% and water consumption in 1100L/h. For these metals included by shaking-table middling, the separation of both flotation and shaking table is carried out, and the total metal content and its copper grade, recovery in metal concentrate 2′ is 72.07% , 31.59% and62.04% respectively, meanwhile the copper grade of tailings in flotation and shaking table are decreased to 1.26% and 2.94%. The wet treatment process can effectively concentrate these valuable metals from waste PCBs.

scholarly journals Evaluation of US EPA Method 3052 Microwave Acid Digestion for Quantification of Majority Metals in Waste Printed Circuit Boards

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1511
Author(s):  
Dagmar Remeteiová ◽  
Silvia Ružičková ◽  
Vladislava Mičková ◽  
Martina Laubertová ◽  
Róberta Slezáková
Keyword(s):  
Environmental Protection Agency ◽  
Metal Content ◽  
Printed Circuit Boards ◽  
Standard Procedure ◽  
Circuit Boards ◽  
Acid Digestion ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Metal Recycling ◽  
Us Epa

Metal content determination is one of the critical aspects of preparing electronic waste for metal recycling. In spite of the fact that end-of-life printed circuit boards are considered to be a secondary resource reservoir, no standard procedure exists for determining the total metal content in this heterogeneous multicomponent material containing plastics, metals, alloys and ceramics. We investigated the utilization of United States Environmental Protection Agency (US EPA) microwave acid digestion (Method 3052) and various modifications of this procedure for effective releasing of Cu, Fe, Ni, Pb and Zn from waste printed circuit boards (WPCBs) from mobile phones. The maximum contents of Cu (22.6 wt.%), Fe (5.0 wt.%), Ni (2.0 wt.%) and Zn (2.6 wt.%) were obtained using the standard (unmodified) US EPA 3052 digestion procedure, but the total digestion of PCB material was not achieved. The solid residue material after digestion by means of the US EPA 3052 method consisted predominantly of oxides (Ca, Mg and Al) and fluorides (Ca and Mg), and some particles contained minor amounts of Fe and Cu.

LEACHING OF METALS FROM WASTE PRINTED CIRCUIT BOARDS (WPCBs) USING SULFURIC AND NITRIC ACIDS

2014 ◽  
Vol 13 (10) ◽  
pp. 2601-2607 ◽  
Author(s):  
Jae-chun Lee ◽  
Manoj Kumar ◽  
Min-Seuk Kim ◽  
Jinki Jeong ◽  
Kyoungkeun Yoo
Keyword(s):  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards

scholarly journals Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate

JOM ◽  
2020 ◽  
Author(s):  
Joona Rajahalme ◽  
Siiri Perämäki ◽  
Roshan Budhathoki ◽  
Ari Väisänen
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Sulfuric Acid Concentration ◽  
Recovery Process ◽  
Copper Recovery ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Acid Consumption

AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen peroxide during leaching, while changes in sulfuric acid concentration were minor. During recirculation of the leachate with up to 5 cycles, copper recovery and product purity remained at high levels while acid consumption was reduced by 60%.

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