scholarly journals The Effect of Specific Conditions on Cu, Ni, Zn and Al Recovery from PCBS Waste Using Acidophilic Bacterial Strains

2016 ◽  
Vol 61 (1) ◽  
pp. 261-264 ◽  
Author(s):  
A. Mrážiková ◽  
J. Kaduková ◽  
R. Marcinčáková ◽  
O. Velgosová ◽  
J. Willner ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Bacterial Culture ◽  
Copper Recovery ◽  
Acidithiobacillus Thiooxidans ◽  
Circuit Boards ◽  
Bacterial Strains ◽  
Printed Circuit ◽  
Copper Zinc ◽  
Static Conditions ◽  
Nickel Dissolution

The objective of this work was to evaluate the influence of static, stirring and shaking conditions on copper, zinc, nickel and aluminium dissolution from printed circuit boards (PCBs) using the mixed acidophilic bacterial culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The results revealed that static conditions were the most effective in zinc and aluminium dissolution. Zinc was removed almost completely under static conditions, whereas maximum of nickel dissolution was reached under the stirring conditions. The highest copper recovery (36%) was reached under stirring conditions. The shaking conditions appeared to be the least suitable. The relative importance of these systems for the bioleaching of copper and nickel decreased in the order: stirring, static conditions, shaking.

scholarly journals Influence Of Used Bacterial Culture On Zinc And Aluminium Bioleaching From Printed Circuit Boards

2015 ◽  
Vol 14 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Anna Mrazikova ◽  
Renata Marcincakova ◽  
Jana Kadukova ◽  
Oksana Velgosova ◽  
Magdalena Balintova
Keyword(s):  
Mixed Culture ◽  
Pure Culture ◽  
Printed Circuit Boards ◽  
Bacterial Culture ◽  
Acidithiobacillus Thiooxidans ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Whole Process ◽  
High Metal ◽  
Main Factor

Abstract Bioleaching processes were used to solubilize metals (Cu, Ni, Zn and Al) from printed circuit boards (PCBs). In this study, a PCBs-adapted pure culture of Acidithiobacillus ferrooxidans, pure culture of Acidithiobacillus thiooxidans and PCBs-adapted mixed culture of A. ferrooxidans and A. thiooxidans were used for recovery of the metals. The study showed that the mixed bacterial culture has the greatest potential to dissolve metals. The maximum metal bioleaching efficiencies were found to be 100, 92, 89 and 20% of Cu, Ni, Zn and Al, respectively. The mixed culture revealed higher bacterial stability. The main factor responsible for high metal recovery was the ability of the mixed culture to maintain the low pH during the whole process. The pure culture of A. thiooxidans had no significant effect on metal bioleaching from PCBs.

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%.

Copper Recovery from Printed Circuit Boards from Smartphones Through Bioleaching

2019 ◽  
pp. 837-844 ◽  
Author(s):  
Lidiane Maria de Andrade ◽  
Carlos Gonzalo Alvarez Rosario ◽  
Mariana Alves de Carvalho ◽  
Denise Crocce Romano Espinosa ◽  
Jorge Alberto Soares Tenório
Keyword(s):  
Printed Circuit Boards ◽  
Copper Recovery ◽  
Circuit Boards ◽  
Printed Circuit

scholarly journals Optimal Thermal Treatment for Effective Copper Recovery in Waste Printed Circuit Boards by Physical Separation: Influence of Temperature and Gas

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1213
Author(s):  
Boram Kim ◽  
Seongsoo Han ◽  
Seungsoo Park ◽  
Seongmin Kim ◽  
Minuk Jung ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Mechanical Strength ◽  
Physical Properties ◽  
Printed Circuit Boards ◽  
Separation Efficiency ◽  
Size Fraction ◽  
Copper Recovery ◽  
Circuit Boards ◽  
Printed Circuit

Printed circuit boards (PCBs) are difficult to recycle because of the layered structure of non-metal (i.e., epoxy resin, glass fiber) and copper. In this work, we conducted a systematic investigation to effectively recover copper from PCB. A thermal treatment was employed for improving the crushing performance of PCB and conducted by varying the temperature and the gas. Then, the mechanical strength, degree of liberation (DL), and copper separation efficiency of the heat-treated and untreated PCBs were investigated. After heat treatment under a 300 °C air atmosphere, the mechanical strength of PCB decreased from 386.36 to 24.26 MPa, and copper liberation improved from 9.3% to 100% in the size range of a coarser size fraction (>1400 μm). Accordingly, when electrostatic separations were performed under these conditions, a high-Cu-grade concentrate and high recovery could be obtained. The results show that the change in the physical properties of the PCBs leads to an improvement in the DL following thermal decomposition at 300 °C in air. Our study elucidates the physical properties of PCBs and the DL under various heat treatment conditions. Furthermore, it shows that the heat treatment condition of 300 °C in air is ideal for recovering copper from the PCB.

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