scholarly journals Effect of Graphite on Copper Bioleaching from Waste Printed Circuit Boards

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 79 ◽  
Author(s):  
Linlin Tong ◽  
Qianfei Zhao ◽  
Ali Kamali ◽  
Wolfgang Sand ◽  
Hongying Yang
Keyword(s):  
Printed Circuit Boards ◽  
Acid Leaching ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Copper Leaching ◽  
Initial Ph ◽  
Efficient Extraction ◽  
Bacteria Culture ◽  
The Impact

The efficient extraction of copper as a valuable metal from waste printed circuit boards (WPCBs) is currently attracting growing interest. Here, we systematically investigated the impact of bacteria on the efficiency of copper leaching from WPCBs, and evaluated the effect of graphite on bioleaching performance. The HQ0211 bacteria culture containing Acidithiobacillus ferrooxidans, Ferroplasma acidiphilum, and Leptospirillum ferriphilum enhanced Cu-leaching performance in either ferric sulfate and sulfuric acid leaching, so a final leaching of up to 76.2% was recorded after 5 days. With the addition of graphite, the percentage of copper leaching could be increased to 80.5%. Single-factor experiments confirmed the compatibility of graphite with the HQ0211 culture, and identified the optimal pulp density of WPCBs, the initial pH, and the graphite content to be 2% (w/v), 1.6, and 2.5 g/L, respectively.

scholarly journals Dismantling of Waste Printed Circuit Boards with the Simultaneous Recovery of Copper: Experimental Study and Process Modeling

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5186
Author(s):  
Szabolcs Fogarasi ◽  
Árpád Imre-Lucaci ◽  
Florica Imre-Lucaci
Keyword(s):  
Environmental Performance ◽  
Printed Circuit Boards ◽  
Electrochemical Process ◽  
Circuit Boards ◽  
Electronic Components ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Different Types ◽  
Leaching Solution ◽  
The Impact

The study was carried out with the aim to demonstrate the applicability of a combined chemical–electrochemical process for the dismantling of waste printed circuit boards (WPCBs) created from different types of electronic equipment. The concept implies a simple and less polluting process that allows the chemical dismantling of WPCBs with the simultaneous recovery of copper from the leaching solution and the regeneration of the leaching agent. In order to assess the performance of the dismantling process, various tests were performed on different types of WPCBs using the 0.3 M FeCl3 in 0.5 M HCl leaching system. The experimental results show that, through the leaching process, the electronic components (EC) together with other fractions can be efficiently dismounted from the surface of WPCBs, with the parallel electrowinning of copper from the copper rich leaching solution. In addition, the process was scaled up for the dismantling of 100 kg/h WPCBs and modeled and simulated using process flow modelling software ChemCAD in order to assess the impact of all steps and equipment on the technical and environmental performance of the overall process. According to the results, the dismantling of 1 kg of WPCBs requires a total energy of 0.48 kWh, and the process can be performed with an overall low environmental impact based on the obtained general environmental indexes (GEIs) values.

scholarly journals Selective leaching of copper from waste printed circuit boards (PCBs) using glycine as a complexing agent

2021 ◽  
Keyword(s):  
Printed Circuit Boards ◽  
Size Fraction ◽  
Complexing Agent ◽  
Copper Extraction ◽  
Circuit Boards ◽  
Selective Leaching ◽  
Ambient Conditions ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Copper Leaching

<p>In this research, the selective leaching of copper from waste printed circuit boards (PCBs) using glycine as a complexing agent was investigated. PCBs were pulverized and sieved, which allowed obtaining a PCBs powder of particle size fraction ≤ 1mm. The PCBs powder has been characterized by several techniques before and after leaching. In order to understand the copper extraction process, the reaction mechanisms, and to determine the optimal leaching parameters, the effects of a range of parameters during copper leaching were investigated, including leaching time, solid-to-liquid ratio, mechanical stirring rate, leaching temperature and glycine concentration. Copper leaching from PCBs waste powder was identified as a complex four-stage gas-liquid-solid process that is carried out slowly under ambient conditions. Glycine shows a very significant selectivity for copper during leaching process allowing dissolving copper from PCBs waste with a percentage of 92.8% under ambient conditions.</p>

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.

Experimental Study on Impact Mechanical Properties of Waste Printed Circuit Boards

2010 ◽  
Vol 113-116 ◽  
pp. 1123-1127
Author(s):  
Nian Xin Zhou ◽  
Ya Qun He ◽  
Chen Long Duan ◽  
Shu Ai Wang
Keyword(s):  
Mechanical Properties ◽  
Printed Circuit Boards ◽  
Impact Load ◽  
Circuit Board ◽  
Circuit Boards ◽  
X Ray ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
The Impact ◽  
Scanning Electron

Comminution is a key part of the reutilization of discarded circuit board. In order to find out the most appropriate method of crushing, the characteristics of the materials and the mechanical properties of resistance impact of discarded circuit boards were studied. The substrate of circuit boards, slots of ISA and PCI were adopted as the specimen. The scanning electron microscope (SEM) and energy disperse X-ray spectroscopy (EDX) were used to characterize and analyze the combined state of the fracturing materials on the specimen surfaces after comminution. Results showed that the metals and nonmetals in the slots were crushed and dissociated easily.At the same time, the metal and nonmetal combined interfaces in the substrate have a trend to be broken and separated under the impact effect, which means the crushing circuit board has a favorable break effect under impact load.

scholarly journals Comparative study on copper leaching from waste printed circuit boards by typical ionic liquid acids

2015 ◽  
Vol 41 ◽  
pp. 142-147 ◽  
Author(s):  
Mengjun Chen ◽  
Jinxiu Huang ◽  
Oladele A. Ogunseitan ◽  
Nengming Zhu ◽  
Yan-min Wang
Keyword(s):  
Ionic Liquid ◽  
Comparative Study ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Copper Leaching

Copper leaching from waste printed circuit boards using typical acidic ionic liquids recovery of e-wastes’ surplus value

2018 ◽  
Vol 78 ◽  
pp. 191-197 ◽  
Author(s):  
Ding-jun Zhang ◽  
Li Dong ◽  
Yong-tong Li ◽  
Yanfei Wu ◽  
Ying-xia Ma ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Surplus Value ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Copper Leaching ◽  
Acidic Ionic Liquids

Characteristics of Bioleaching Copper Remainders of Waste Printed Circuit Boards

2014 ◽  
Vol 955-959 ◽  
pp. 2649-2652
Author(s):  
Zheng Xu ◽  
Tao Yang ◽  
Li Mei Yang ◽  
Yi Han Na Hu
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Printed Circuit Boards ◽  
Acid Leaching ◽  
Surface Shape ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Eds Analysis ◽  
Scanning Electron

Printed circuit boards are part of computer and their compositions are quite varied, containing polymers, ceramics and metals. Bioleaching copper from the printed circuit boards (PCB) by Acidithiobacillus ferrooxidans (A. f.) had been proved to be feasible in our recent work. The characteristics of the remainders of copper were carefully observed by field emission scanning electron microscope (FESEM). It is found that the leaching pits were common on the surface of the leached copper and some crystal substances were also found on the surface. The EDS analysis was used to determine the elements of different area. The leaching pits area was consisted of copper and the crystal area was consisted of copper and oxygen. The surface shape of bioleached copper was compared with acid leaching copper and Fe3+ leaching copper. Different leaching method can get different morphology due to the different leaching mechanisms. The results can help us to understand the mechanism of the copper bioleaching by microorganism.

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