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

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.

2021 ◽  
Author(s):  
Weifang Chen ◽  
Yongkai Shu ◽  
Yonglun Li ◽  
Yanjun Chen ◽  
Jianbo Wei

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.


2015 ◽  
Vol 4 (2) ◽  
pp. 70-75
Author(s):  
Şule Atasever ◽  
Pınar A. Bozkurt ◽  
Muammer Canel

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.


Proceedings ◽  
2019 ◽  
Vol 29 (1) ◽  
pp. 19
Author(s):  
Paul Ghioca ◽  
Madalina Elena David ◽  
Mircea Ioan Filipescu ◽  
Ramona Marina Grigorescu ◽  
Lorena Iancu ◽  
...  

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]. [...]


2014 ◽  
Vol 997 ◽  
pp. 638-641
Author(s):  
Yue Bin Han ◽  
Li De Li ◽  
Guang Ming Li ◽  
Wen Zhi He

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.


2012 ◽  
Vol 39 (8) ◽  
pp. 3611-3630 ◽  
Author(s):  
Shibing Hou ◽  
Yunxia He ◽  
Deming Yang ◽  
Zhenming Xu

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
P. Sivakumar ◽  
D. Prabhakaran ◽  
M. Thirumarimurugan

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.


Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 887 ◽  
Author(s):  
Xingbang Wan ◽  
Jani Fellman ◽  
Ari Jokilaakso ◽  
Lassi Klemettinen ◽  
Miikka Marjakoski

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.


2015 ◽  
Vol 787 ◽  
pp. 18-21 ◽  
Author(s):  
A.G. Ganesh Kumar ◽  
G. Ranganath ◽  
S.N. Mani Varmaa ◽  
S. Shylin H. Jose ◽  
M. Sakthivel

Recycling of Printed Circuit Boards (PCB) has been carried out by powdering it into granular size of less than 10 microns. The properties of PCB reveal that it possesses density of 1.3 g/cm3 and Tensile Strength of 310 MPa which is comparatively high when compared to the Polycarbonate material which is normally used in the fabrication of Riot shield. The PCB material was subjected to SEM and EDAX analysis for determining their structure, porosity and material composition. Riot shield fabricated from PCB reduces the environmental effects of E-waste PCBs by the recycling technique, improves the material strength and reduces the weight and cost to a larger extent.


2010 ◽  
Vol 113-116 ◽  
pp. 1123-1127
Author(s):  
Nian Xin Zhou ◽  
Ya Qun He ◽  
Chen Long Duan ◽  
Shu Ai Wang

Comminution is a key part of the reutilization of discarded circuit board. In order to find out the most appropriate method of crushing, the characteristics of the materials and the mechanical properties of resistance impact of discarded circuit boards were studied. The substrate of circuit boards, slots of ISA and PCI were adopted as the specimen. The scanning electron microscope (SEM) and energy disperse X-ray spectroscopy (EDX) were used to characterize and analyze the combined state of the fracturing materials on the specimen surfaces after comminution. Results showed that the metals and nonmetals in the slots were crushed and dissociated easily.At the same time, the metal and nonmetal combined interfaces in the substrate have a trend to be broken and separated under the impact effect, which means the crushing circuit board has a favorable break effect under impact load.


2020 ◽  
Author(s):  
V.M. Alexeenko ◽  
L.G. Ananieva ◽  
A.A. Zherlitsyn ◽  
S.S. Kondratiev ◽  
M.V. Korovkin ◽  
...  

The results of the electric discharge crushing of PCB (printed circuit boards) to millimeter-sized fractions suitable for separation of the metal from the dielectric are presented. The crushing was performed on a high-voltage repetitively pulsed generator with varying the number of pulses. It was determined the dependences of the fractional composition of crushing products on the number of pulses in the cycle. Crushing products were studied for definition separation of metal from the dielectric with optical microscope. The results of the work confirm the possibility of electric discharge crushing various types of PCB, including fiberglass PCB with four layers. Keywords: high voltage fragmentation, waste printed circuit board, recycling


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