scholarly journals Optimization Studies on Recovery of Metals from Printed Circuit Board Waste

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
P. Sivakumar ◽  
D. Prabhakaran ◽  
M. Thirumarimurugan
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Lead Nitrate ◽  
Acid Leaching ◽  
Circuit Board ◽  
Copper Recovery ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Electrode Combination ◽  
Lead Metal

The aim of the study was to recover copper and lead metal from waste printed circuit boards (PCBs). The electrowinning method is found to be an effective recycling process to recover copper and lead metal from printed circuit board wastes. In order to simplify the process with affordable equipment, a simple ammonical leaching operation method was adopted. The selected PCBs were incinerated into fine ash powder at 500°C for 1 hour in the pyrolysis reactor. Then, the fine ash powder was subjected to acid-leaching process to recover the metals with varying conditions like acid-base concentration, electrode combination, and leaching time. The relative electrolysis solution of 0.1 M lead nitrate for lead and 0.1 M copper sulphate for copper was used to extract metals from PCBs at room temperature. The amount of lead and copper extracted from the process was determined by an atomic absorption spectrophotometer, and results found were 73.29% and 82.17%, respectively. Further, the optimum conditions for the recovery of metals were determined by using RSM software. The results showed that the percentage of lead and copper recovery were 78.25% and 89.1% should be 4 hrs 10 A/dm2.

scholarly journals Selective Copper Recovery by Acid Leaching from Printed Circuit Board Waste Sludge

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 293 ◽  
Author(s):  
Ha Bich Trinh ◽  
Seunghyun Kim ◽  
Jaeryeong Lee
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Acid Leaching ◽  
Kinetic Studies ◽  
Control Model ◽  
Circuit Board ◽  
Copper Recovery ◽  
H2so4 Concentration ◽  
Printed Circuit ◽  
Waste Sludge

The most challenging issue associated with recycling the sludge generated from printed circuit boards (PCBs) is the separation of copper (Cu) from iron (Fe), using multi-stage leaching, or adding oxidizing and precipitating agents. Herein we investigated simple acid leaching to effectively extract copper and limit iron dissolution. Selective copper leaching was achieved with all the acids studied, including HCl, HNO3, and H2SO4. The lower concentration of acid solutions resulted in a larger difference in leachabilities between Cu and Fe. Among three leachates, the H2SO4 solution performed effectively on the selective leaching of Cu and Fe. Adjusting the pulp density to 4% and the H2SO4 concentration at ~0.2 M, accomplished ~95% Cu leaching and reduced the Fe extraction to less than 5%. Kinetic studies revealed that Cu leaching followed the ash diffusion-controlled mechanism. Aactivation energy (Ea) of 9.8 kJ/mol was determined for the first 10 min of leaching. Further, leaching up to 60 min corresponded to a mixed control model, increasing the Ea to 20.9 kJ/mol. The change in the control model with regard to the two leaching stages can be attributed to the Cu hydroxide and metal phases present in the original sample. A simple, economically attractive H2SO4 acid leaching process was demonstrated, recovering Cu efficiently and selectively from PCBs waste sludge under moderate conditions.

Research on Liberation Mechanism of the Impact Crushing Waste Printed Circuit Board

2010 ◽  
Vol 113-116 ◽  
pp. 730-734 ◽  
Author(s):  
Chen Long Duan ◽  
Yue Min Zhao ◽  
Jing Feng He ◽  
Nian Xin Zhou
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Distribution Model ◽  
Evaluation Indexes ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Waste Printed Circuit Board ◽  
Impact Crushing ◽  
The Impact

The reutilization of waste Printed Circuit Boards (PCB) is a focused topic in the field of environment protection and resource recycling, and the crushing is the crucial process for recycling waste PCB. A hamper impacting crusher was used to achieve metals crushing liberation from non-metals, the liberation mechanism of PCB can be explained by dispersion liberation accompanied disengaging liberation. The Rosin-Rammler distribution model of crushed PCB particle was put forward. The evaluation indexes show that Rosin-Rammler function can accurately describe size distribution of PCB particles because the convergence property R2 is 0.99694 and fitting error E is 4.80658. The selective crushing is appearance with metals concentrated in coarser fraction and non-metals in finer size during comminution processing. The impact crushing is an effective method to metals liberation of PCB particles.

scholarly journals Behavior of Waste Printed Circuit Board (WPCB) Materials in the Copper Matte Smelting Process

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 887 ◽  
Author(s):  
Xingbang Wan ◽  
Jani Fellman ◽  
Ari Jokilaakso ◽  
Lassi Klemettinen ◽  
Miikka Marjakoski
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Precious Metals ◽  
Melting Behavior ◽  
Inert Atmosphere ◽  
Circuit Board ◽  
Copper Smelting ◽  
Smelting Process ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards

The amount of waste electrical and electronic equipment (WEEE) in the world has grown rapidly during recent decades, and with the depletion of primary ores, there is urgent need for industries to study new sources for metals. Waste printed circuit boards (WPCB) are a part of WEEE, which have a higher concentration of copper and precious metals when compared to primary ore sources. PCB materials can be processed using pyrometallurgical routes, and some industrial processes, such as copper flash smelting, have utilized this type of waste in limited amounts for years. For the purpose of recycling these materials through smelting processes, this work studied the behavior of WPCB scrap when dropped on top of molten slag. A series of experiments was carried out during this research at a temperature of 1350 °C, in an inert atmosphere with different melting times. The time required for complete melting of the PCB pieces was 2–5 min, after which molten alloy droplets containing Cu, Pb, Sn, Ni, Au, and Ag formed and started descending toward the bottom of the crucible. The ceramic fraction of the PCB material mixed with slag and the polymer fraction was pyrolyzed during the high-temperature experiments. The results give an understanding of PCB melting behavior and their use as a part of the smelting furnace feed mixture. However, more research is needed to fully understand how the different elements affect the process as the amount of PCB in the feed increases. The physical behavior and distribution of PCB materials in fayalite slag during the smelting process are outlined, and the results of this work form a basis for future studies about the chemical reaction behavior and kinetics when PCB materials are introduced into the copper smelting process.

scholarly journals Co-Pyrolysis of Waste Printed Circuit Boards With Iron Compounds for Br-Fixing and Material Recovery

2021 ◽  
Author(s):  
Weifang Chen ◽  
Yongkai Shu ◽  
Yonglun Li ◽  
Yanjun Chen ◽  
Jianbo Wei
Keyword(s):  
Iron Oxides ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Glass Fibers ◽  
Liquid Product ◽  
Circuit Board ◽  
Printed Circuit ◽  
Gaseous Products ◽  
Waste Printed Circuit Boards ◽  
Waste Printed Circuit Board

Abstract Waste printed circuit board was co-pyrolyzed with iron oxides and iron salts. Solid, liquid and gaseous products were collected and characterized. Co-pyrolysis with FeCl2, FeCl3 or FeSO4 was able to increase the yield of liquid product which was rich in phenol and its homologues. Also, the addition of co-pyrolysis reagents reduced the release of brominated organics to liquid as Br was either fixed as FeBr3 in solids or released as HBr. In particular, FeCl2 showed the best ability to reduce the release of Br-containing organics to liquid compared with FeCl3 and FeSO4. Solid residuals were rich in iron oxides, glass fibers and charred organics with surface areas of 20.6-26.5 m2/g. CO2 together with a small amount of CH4 and H2 were detected in the gaseous products. Overall, co-pyrolysis could improve the quantity and quality of liquid oil which could be reused as chemical or energy sources. Pyrolysis of waste printed circuit board was promising as a method for recycling.

Pyrolysis of Waste Printed Circuit Board Particles

2015 ◽  
Vol 4 (2) ◽  
pp. 70-75
Author(s):  
Şule Atasever ◽  
Pınar A. Bozkurt ◽  
Muammer Canel
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Waste ◽  
Circuit Board ◽  
Electronic Apparatus ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Waste Printed Circuit Board ◽  
Different Temperatures ◽  
Apparatus And Instruments

Electrical and electronic apparatus and instruments which are obsolete value in use or completion of the life can be defined as e-waste. E-waste is one of the fastest growing types of hazardous waste. Printed circuit boards a major component of this waste. In this study, printed circuit board particles of mobile phone (MPCB) were used as electronic waste. MPCB waste was obtained from a local electronic waste factory. The elemental analysis and ICP-MS analysis were performed on these electronic wastes and thereafter pyrolysis runs were carried out between 500 and 900°C in a horizontal furnace. The liquid yields were determined and compared at different temperatures.

scholarly journals Composites of Styrene-Butadiene Block Copolymer Reinforced with Waste Printed Circuit Boards (WPCB)

Proceedings ◽  
2019 ◽  
Vol 29 (1) ◽  
pp. 19
Author(s):  
Paul Ghioca ◽  
Madalina Elena David ◽  
Mircea Ioan Filipescu ◽  
Ramona Marina Grigorescu ◽  
Lorena Iancu ◽  
...  
Keyword(s):  
Flame Retardants ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Circuit Boards ◽  
Organic Part ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Waste Printed Circuit Board ◽  
Styrene Butadiene

The organic part of the waste printed circuit board (WPCB) contains mainly epoxy resin, fiberglass and brominated flame retardants, a composition that makes it quite difficult to reuse [1,2]. [...]

Influence of non-metallic parts of waste printed circuit boards on the properties of plasticised polyvinyl chloride recycled from the waste wire

2019 ◽  
Vol 37 (6) ◽  
pp. 569-577 ◽  
Author(s):  
Rajesha K Das ◽  
Omdeo K Gohatre ◽  
Manoranjan Biswal ◽  
Smita Mohanty ◽  
SK Nayak
Keyword(s):  
Thermal Properties ◽  
Polyvinyl Chloride ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Metallic Parts ◽  
Chloride Matrix

Extreme complexity in the range of metallic and non-metallic parts present in waste printed circuit boards leads to incineration for collecting valuable metals. The non-metallic parts of the printed circuit board can be used effectively without affecting the environment. In this study, the non-metallic parts of the printed circuit board, which is made up by cross-linked resin and fibre, was used as a filler in recycled plasticised polyvinyl chloride collected from waste wires and cables. The properties of the plasticised polyvinyl chloride matrix and plasticised polyvinyl chloride–non-metallic parts of printed circuit board composite were compared with each other by means of mechanical properties and thermal properties. Both mechanical and thermal properties results indicated that incorporation of non-metallic parts of printed circuit board significantly improved the hardness, stiffness, abrasion resistance and thermal stability of plasticised polyvinyl chloride–non-metallic parts of printed circuit board composite; however, the tensile strength of the composite material is not improved because of poor adhesion between the plasticised polyvinyl chloride matrix and non-metallic parts of printed circuit board filler. The poor chemical interaction is also observed from Fourier transform infrared spectroscopy results. This plasticised polyvinyl chloride–non-metallic parts of printed circuit board composite can reduce the leaching of a hazardous element from the printed circuit board with effective utilisation of plastics fraction from waste wires and cables.

Study on Recovery of Metals from Printed Circuit Board Using a Gas-Liquid Fluidized Bed

2014 ◽  
Vol 997 ◽  
pp. 638-641
Author(s):  
Yue Bin Han ◽  
Li De Li ◽  
Guang Ming Li ◽  
Wen Zhi He
Keyword(s):  
Fluidized Bed ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Particle Diameter ◽  
Air Separation ◽  
Circuit Board ◽  
Operation Condition ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
The Impact

Comminuting and enrichment are the key technology to recycle waste printed circuit boards (WPCBs), in this paper the mechanical separation of WPCBs, comminuting by bang comminute and enrichment by air-solid fluidized bed, was studied. Experiments were designed to examine the impact of the airflow velocity and particle diameter to the air separation process, in order to optimize the operation condition. The results illustrated that it is feasible and very effective to apply gas-solid fluidized bed to recycle WPCBs.

Study on the Promotion Effect of Microwave-Metal Discharge on the Microwave Pyrolysis of Electronic Waste

2015 ◽  
Vol 1088 ◽  
pp. 843-847 ◽  
Author(s):  
Jing Sun ◽  
Wen Long Wang ◽  
Chun Yuan Ma ◽  
Qin Yan Yue
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Waste ◽  
Absorption Capacity ◽  
Circuit Board ◽  
Microwave Pyrolysis ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Metal Discharge ◽  
In The Beginning

This paper discussed the role of microwave-metal discharge on the microwave induced pyrolysis of electronic waste. Two kinds of waste printed circuit boards (WPCB) were selected as the representatives of electronic waste and their pyrolysis processes under both conventional and microwave heating schemes were studied comparatively to reveal the effect of metal discharge. The copper-clad laminated printed circuit board (PCB) is deficient in absorbing microwaves, leading to inefficient microwave pyrolysis of this kind of electronic waste. The discharge caused by introducing metalliferous materials with metal tips or corners in the electromagnetic fields can result in high local temperature and complement the deficiency in the microwave absorption. The pyrolytic process can be promoted greatly by the thermal effect of discharge in the beginning and the enhanced consequent wave-absorption capacity as a result of the generated pyrolytic coke.

Dielectric Breakdown in Printed Circuit Boards at Elevated Temperatures

1996 ◽  
Author(s):  
P. Singh ◽  
G.T. Galyon ◽  
J. Obrzut ◽  
W.A. Alpaugh
Keyword(s):  
Experimental Data ◽  
Thermal Degradation ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Elevated Temperatures ◽  
Dielectric Breakdown ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Data Matching

Abstract A time delayed dielectric breakdown in printed circuit boards, operating at temperatures below the epoxy resin insulation thermo-electrical limits, is reported. The safe temperature-voltage operating regime was estimated and related to the glass-rubber transition (To) of printed circuit board dielectric. The TG was measured using DSC and compared with that determined from electrical conductivity of the laminate in the glassy and rubbery state. A failure model was developed and fitted to the experimental data matching a localized thermal degradation of the dielectric and time dependency. The model is based on localized heating of an insulation resistance defect that under certain voltage bias can exceed the TG, thus, initiating thermal degradation of the resin. The model agrees well with the experimental data and indicates that the failure rate and truncation time beyond which the probability of failure becomes insignificant, decreases with increasing glass-rubber transition temperature.

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