Processing of a Metal Concentrate From Ground Waste Printed Circuit Boards in Acidic Media Using Hydrogen Peroxide as Oxidant

Silva, Calvin Sampaio Moreira da; Zeba, Guido Tande Crespo; Rocha, Christiano Mota Rodrigues da; Gismonti, Pedro Rosário; Afonso, Júlio Carlos; Silva, Rubens Souza da; Vianna, Cláudio Augusto; Mantovano, José Luiz

doi:10.21577/0100-4042.20170575

Cited by 2 publications

(4 citation statements)

References 2 publications

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“…Though PCB contains many metals including Cu, Ag, Au, Sn, and Ni to state a few, Cu is the focus of this study because it has the single highest composition of all metals in most PCB samples including that of scrap laptop computers. 13,16 The average Cu concentration in the PCB pieces was determined to be (0.84 ± 0.13) mg/g, which is lower than that reported by other studies, 33,34 and this was attributed to the fact that the Cu content in the PCB of laptop computers are generally lower than that in other products like desktop computers and television sets. 35 The relatively large error (standard deviation) in the Cu content value was attributed to a large variation in the Cu content in different parts of the large PCB from which the samples were cut.…”

Section: The Average Copper Content Of the Pcb Piecescontrasting

confidence: 53%

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Box-Behnken Optimization and Theoretical Study for Copper Leaching from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

Olasupo

Odubola²,

Akintayo³

et al. 2022

SCE

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The hydrometallurgical method of copper leaching from scrap electronics is commonly undertaken using pulverized printed circuit boards. Though studies on the use of organic acids like citric and oxalic acids for copper removal are well documented, those on the use of malonic acid are rare. Herein, we report on the investigation of the efficiencies of mixtures of malonic acid and hydrogen peroxide for copper leaching from unpulverized scrap PCB by the Box-Behnken design and the theoretical determination of the most stable copper-malonic acid complex. The average copper content in each unpulverized printed circuit board was found to be (0.84 ± 0.13) mg/g following aqua-regia digestion and atomic absorption spectrophotometry measurement. The conditions at which the highest leaching efficiency of 51.3% was obtained were a malonic acid concentration of 0.5 M, a hydrogen peroxide concentration of 1.0 M, and a contact time of 75 min. The contact time was the most significant individual parameter that influenced the efficiency of copper leached with a p-value of 0.001. Theoretical calculations show that malonic acid prefers to coordinate with copper in a 2:1 malonic acid: copper ratio. This study shows that appreciable amounts of copper can be leached from the minimally processed unpulverized printed circuit board.

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Section: The Average Copper Content Of the Pcb Piecescontrasting

confidence: 53%

“…Typical acids used for base metal extraction are sulfuric acid, 8 nitric acid, 9 hydrochloric acid, 10 trifluoromethanesulfonic acid, 9 and mixtures of acids. 11 These acids have often been used in combination with oxidants such as oxygen, H 2 O 2 , ferric salts, and chlorine gas 12,13 to achieve higher leaching efficiencies.…”

Section: Introductionmentioning

confidence: 99%

Box-Behnken Optimization and Theoretical Study for Copper Leaching from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

Olasupo

Odubola²,

Akintayo³

et al. 2022

SCE

View full text Add to dashboard Cite

show abstract

“…It was important to determine the initial Cu content of the PCB to have a reference to which the efficiency of the test leach solution (mixture of malonic acid and H2O2) can be compared. Though PCBs contain many metals including Cu, Ag, Au, Sn, and Ni to state a few, Cu is the focus of this study because it has the single highest composition of all metals in most PCB samples including that of scrap laptop computers [15,25]. The average Cu concentration in the PCB pieces was determined to be (0.84±0.13) mg/g (where 0.13 is the standard deviation of the mean), which is lower than that reported by other studies [41,42], and this was attributed to the fact that the Cu content in the PCBs of laptop computers are generally lower than that in other products like desktop computers and television sets [43].…”

Section: 2mentioning

confidence: 99%

“…Typical acids used for base metal extraction are sulfuric acid [10], nitric acid [11], hydrochloric acid [12], trifluoromethanesulfonic acid [11], and mixtures of acids [13]. These acids have often been used in combination with oxidants such as oxygen, H2O2, ferric salts, and chlorine gas [14,15]. Of these leaching agents, sulfuric acid is the favoured solvent predominantly because its market price is lower than the other acids and it has been proven to be an efficient solvent, especially for the recovery of Cu [16].…”

Section: Introductionmentioning

confidence: 99%

Box-Behnken Optimization and Theoretical Study for Copper Recovery from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

Aderibigbe¹,

Olasupo

Odubola

et al. 2022

Preprint

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Copper (Cu) is a major target in metal recovery during the recycling of scrap printed circuit boards (PCBs). Herein, we report on the optimization of parameters for the leaching of Cu from scrap PCB pieces by malonic acid and hydrogen peroxide (H2O2). Large PCBs obtained from scrap laptop computers were cut into smaller 2 cm by 2 cm pieces and de-epoxidized by NaOH treatment. The average Cu content in each PCB piece was determined by complete solubilization in aqua-regia and found to be (0.84±0.13) mg/g. An optimization study of three parameters including malonic acid concentration, H2O2 concentration, and contact time was carried out through the Box-Behnken design. Analysis of variance data revealed that the linear model was best fitted to the experimental data with R2 = 0.9591 and R2 (adjusted) = 0.8652, but the predictive power of the model was low with R2 (predicted) = 0.2298. The conditions at which the highest leaching efficiency of 51.3% was obtained were a malonic acid concentration of 0.5 M, a H2O2 concentration of 1.0 M, and a contact time of 75 min. The contact time was the most significant individual parameter that influenced the efficiency of Cu leached with a p-value of 0.001. Response surface plots revealed that high leaching efficiencies were observed at high malonic acid and H2O2 concentrations at prolonged contact time. Theoretical calculations show that the malonic acid prefers to coordinate with Cu in a 2:1 malonic acid: Cu ratio.

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Processing of a Metal Concentrate From Ground Waste Printed Circuit Boards in Acidic Media Using Hydrogen Peroxide as Oxidant

Cited by 2 publications

References 2 publications

Box-Behnken Optimization and Theoretical Study for Copper Leaching from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

Box-Behnken Optimization and Theoretical Study for Copper Leaching from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

Box-Behnken Optimization and Theoretical Study for Copper Recovery from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

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