Pressure leaching of metals from waste printed circuit boards using sulfuric acid

JOM ◽  
2011 ◽  
Vol 63 (8) ◽  
pp. 29-32 ◽  
Author(s):  
Manis K. Jha ◽  
Jae-chun Lee ◽  
Archana Kumari ◽  
Pankaj K. Choubey ◽  
Vinay Kumar ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Pressure Leaching ◽  
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%.

scholarly journals Recovery of Ag, Au, and Pt from Printed Circuit Boards by Pressure Leaching

Recycling ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 67
Author(s):  
Guadalupe Martinez-Ballesteros ◽  
Jesus Leobardo Valenzuela-García ◽  
Agustin Gómez-Alvarez ◽  
Martin Antonio Encinas-Romero ◽  
Flerida Adriana Mejía-Zamudio ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Renewable Resources ◽  
Printed Circuit Boards ◽  
Precious Metals ◽  
Pressure Leaching ◽  
Circuit Boards ◽  
Green Method ◽  
Printed Circuit ◽  
Second Stage ◽  
Metals Extraction

Reclamation of printed circuit boards (PCBs) to recover metals is gaining growing attention due to minerals being non-renewable resources. Currently, metals extraction from PCBs through an efficient and green method is still under investigation. The present investigation concerns the recycling of printed circuit boards using hydrometallurgical processes. First, the basic metals (Cu, Ni, Zn and Fe) were separated using a sulfuric acid solution at moderate temperatures. The remaining solids were characterized by SEM-EDS, whereby a high content of precious metals (Au, Ag and Pt) was observed. In the second stage, solids were leached with a solution of HCl and NaClO in a 1-L titanium reactor with varied oxygen pressure (0.2, 0.34 and 0.55 MPa), temperature (40, 50 and 80 °C) and concentration of HCl (2 and 4 M), obtaining extractions above 95% at [HCl] = 4 M, P = 0.34 MPa and T = 40 °C. The extraction increased depending on the concentration of HCl. Eh–pH diagrams for Ag–Cl–H2O, Au–Cl–H2O and Pt–Cl–H2O were constructed to know the possible species in the solution.

scholarly journals Simulation and economic analysis of a hydrometallurgical approach developed for the treatment of waste printed circuit boards (WPCB)

2018 ◽  
Vol 20 (4) ◽  
pp. 695-699
Keyword(s):  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Material Balance ◽  
Precious Metals ◽  
Industrial Plant ◽  
Circuit Boards ◽  
Metal Powders ◽  
Printed Circuit ◽  
Leaching Process ◽  
Waste Printed Circuit Boards

<p>This paper presents the main achievements of a hydrometallurgical process to recover base and precious metals from waste printed circuit boards (WPCB). The technology comprises a first leaching process performed in a two-step counter current way with sulfuric acid and hydrogen peroxide for base metals solubilization and a consecutive cross leaching process with thiourea, ferric sulfate and sulfuric acid to extract precious metals. Furthermore, the reach solutions are subjected to cementation procedure with zinc powder to recover the elements of interests as metal powders. The spent solution achieved after cementation of precious metals is partially recycled within the process and the other part is treated by Fenton process and then neutralized with lime. Considering the achieved results at the laboratory level, the entire procedure was simulated using SuperPro Designer software to determine the process economy for an industrial plant. Besides this, the use of this software allows achieving the material balance of a process and the design of the plant. As a result, the process implementation at a larger scale is simulated and the main issues that can result in such a case can be determined and solved.</p>

scholarly journals High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 363
Author(s):  
Altansukh Batnasan ◽  
Kazutoshi Haga ◽  
Hsin-Hsiung Huang ◽  
Atsushi Shibayama
Keyword(s):  
High Pressure ◽  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Pure Gold ◽  
Circuit Boards ◽  
Gold Extraction ◽  
Selective Precipitation ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Oxidative Leaching

: This paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide leaching followed by reduction precipitation. Base metals present in WPCB ash were removed via HPOL using a diluted sulfuric acid solution at elevated temperatures. Effects of potassium iodide concentration, hydrogen peroxide concentration, sulfuric acid concentration, leaching temperature, and leaching time on gold extraction from pure gold chips with KI–H2O2–H2SO4 were investigated. The applicability of the optimized iodide leaching process for the extraction of gold from the leach residue obtained after HPOL were examined at different pulp densities ranging from 50 g/t to 200 g/t. Results show that the removal efficiency was 99% for Cu, 95.7% for Zn, 91% for Ni, 87.3% for Al, 82% for Co, and 70% for Fe under defined conditions. Under the optimal conditions, the percentage of gold extraction from the gold chips and the residue of WPCBs was 99% and 95%, respectively. About 99% of the gold was selectively precipitated from the pregnant leach solution by sequential precipitation with sodium hydroxide and L-ascorbic acid. Finally, more than 93% of gold recovery was achieved from WPCB ash by overall combined processes.

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 Food Waste-Assisted Metal Extraction from Printed Circuit Boards: The Aspergillus niger Route

2021 ◽  
Vol 9 (5) ◽  
pp. 895
Author(s):  
Carlotta Alias ◽  
Daniela Bulgari ◽  
Fabjola Bilo ◽  
Laura Borgese ◽  
Alessandra Gianoncelli ◽  
...  
Keyword(s):  
Solid State ◽  
Aspergillus Niger ◽  
Food Waste ◽  
Solid State Fermentation ◽  
Printed Circuit Boards ◽  
Electronic Waste ◽  
Metal Extraction ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards

A low-energy paradigm was adopted for sustainable, affordable, and effective urban waste valorization. Here a new, eco-designed, solid-state fermentation process is presented to obtain some useful bio-products by recycling of different wastes. Urban food waste and scraps from trimmings were used as a substrate for the production of citric acid (CA) by solid state fermentation of Aspergillus niger NRRL 334, with a yield of 20.50 mg of CA per gram of substrate. The acid solution was used to extract metals from waste printed circuit boards (WPCBs), one of the most common electronic waste. The leaching activity of the biological solution is comparable to a commercial CA one. Sn and Fe were the most leached metals (404.09 and 67.99 mg/L, respectively), followed by Ni and Zn (4.55 and 1.92 mg/L) without any pre-treatments as usually performed. Commercial CA extracted Fe more efficiently than the organic one (123.46 vs. 67.99 mg/L); vice versa, biological organic CA recovered Ni better than commercial CA (4.55 vs. 1.54 mg/L). This is the first approach that allows the extraction of metals from WPCBs through CA produced by A. niger directly grown on waste material without any sugar supplement. This “green” process could be an alternative for the recovery of valuable metals such as Fe, Pb, and Ni from electronic waste.

Physical pre-concentration and ammonium leaching of metal copper from waste printed circuit boards

2021 ◽  
pp. 128512
Author(s):  
Shun-xiang Shi ◽  
Chun-chen Nie ◽  
Hong-hao Chang ◽  
Peng Wu ◽  
Zheng-jie Piao ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards
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