scholarly journals Influence of a Polycarboxylate Based Solution on Stability of Hydrogen Peroxide and Application to E-waste Leaching

2020 ◽  
Vol 26 (1) ◽  
pp. 17-23
Author(s):  
Ersin Y. Yazici
Keyword(s):  
Hydrogen Peroxide ◽  
Printed Circuit Boards ◽  
Catalytic Decomposition ◽  
Copper Extraction ◽  
Circuit Boards ◽  
H2o2 Decomposition ◽  
Printed Circuit ◽  
High Consumption ◽  
Alkaline Conditions ◽  
Extraction Of Metals

Hydrogen peroxide with its high oxidising potential is commonly used in hydrometallurgical extraction of metals from ores, anode slimes and waste materials (e.g. WEEE) and treatment of cyanidation effluents. Main detraction to H2O2 is its rapid catalytic decomposition leading to prohibitively high consumption. Effect of pH (0-4), Cu(II) (0-10 g.l-1) and temperature (20-80°C) on H2O2 stability was investigated using response surface methodology. Influence of neutral-alkaline conditions (pH 7.3-11.8) and presence of solids (1-20% w/v) was also tested. A polycarboxylate based solution (PBS) was utilised to improve H2O2 stabilisation. The significance order of parameters on H2O2 decomposition was temperature > pH > Cu(II). Elevating the level of these parameters increased H2O2 decomposition. The activation energy (60.7±2.5 kJ.mol-1) indicated a chemically controlled process. Alkaline conditions (up to pH 11.8) led to higher H2O2 decomposition. Presence of solids adversely affected H2O2 stability under certain conditions. The addition of PBS significantly improved (up to 54%) H2O2 stability in the presence of copper. The presence of PBS in H2SO4-H2O2 leaching of waste of printed circuit boards (WPCBs) enhanced copper extraction by up to 19%. PBS can be suitably utilised to stabilise and hence reduce H2O2 consumption in aqueous solutions particularly in the presence of copper.

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 Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor

2015 ◽  
Vol 41 ◽  
pp. 148-158 ◽  
Author(s):  
Michael L.M. Rodrigues ◽  
Versiane A. Leão ◽  
Otavio Gomes ◽  
Fanny Lambert ◽  
David Bastin ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Thermophilic Bacteria ◽  
Copper Extraction ◽  
Rotating Drum ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Rotating Drum Reactor

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>

A New Technology for Recovery of Metals from Waste Printed Circuit Boards

2014 ◽  
Vol 675-677 ◽  
pp. 698-703 ◽  
Author(s):  
Wei Liu ◽  
Chao Liang ◽  
Wen Qing Qin ◽  
Fen Jiao
Keyword(s):  
Printed Circuit Boards ◽  
Size Range ◽  
New Technology ◽  
Shaking Table ◽  
Copper Recovery ◽  
Copper Extraction ◽  
Circuit Boards ◽  
Pressure Oxidation ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards

Recycling of metallic fractions from waste printed circuit boards (PCBs) using gravity separation and hydrometallurgy was investigated. The obtained research fruits were listed as follows: (1) When being pulverized to finer than 0.4mm, waste PCBs could be generally dissociated from plastics. (2) Shaking table was shown to be suitable for processing pulverized PCBs. Pulverized PCBs containing 6.97% copper was enriched to 33.55% in a single operation and the copper recovery was 90.3% in the best size range of separation. (3) Pressure oxidation leaching was shown to be effective for separating copper from aluminum and tin. The leaching extraction of aluminum and tin were 86.6% and 96.3%, copper extraction was 1% or less under the optimal conditions.

scholarly journals Green Zero-Waste Metal Extraction and Recycling from Printed Circuit Boards

2021 ◽  
Vol 5 (1) ◽  
pp. 39
Author(s):  
Halimeh Askari Sabzkoohi ◽  
Georgios Kolliopoulos
Keyword(s):  
Circular Economy ◽  
Printed Circuit Boards ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Metal Extraction ◽  
Circuit Boards ◽  
Acid Base ◽  
Zero Waste ◽  
Printed Circuit ◽  
Extraction Of Metals

The development of a truly circular economy necessitates the recovery and recycling of resources from secondary streams. In this work, we studied the extraction of metals from printed circuit boards (PCBs) using choline chloride: ethylene glycol deep eutectic solvents: Cu, Ni, Zn, and Sn were selectively extracted from the PCBs, with >75% extraction after 72 h for Cu, Ni, and Sn, and circa. 45% extraction for Zn. This solvometallurgical approach promises to minimize the use of water and acid/base reagents in processing. The results show a considerable ability to compete with current methods of metal extraction and therefore generate a strong potential to attain the goal of a sustainable circular economy via zero-waste green urban mining.

Fast copper extraction from printed circuit boards using supercritical carbon dioxide

2015 ◽  
Vol 45 ◽  
pp. 289-297 ◽  
Author(s):  
C.O. Calgaro ◽  
D.F. Schlemmer ◽  
M.D.C.R. da Silva ◽  
E.V. Maziero ◽  
E.H. Tanabe ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Printed Circuit Boards ◽  
Copper Extraction ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Supercritical Carbon
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