Efficient Recycling of Printed Circuit Boards from Disassembly/Separation Process of waste LCD TVs: Composition Analysis and Value-wise Classification

Wastes from old electronic devices represent a significant part of the electronic scrap generated in developing countries, being commonly sold by collectors as low-value material to recycling hubs abroad. Upgrading the quality of this waste type could drive the revenue of recyclers, and thus, boost the recycling market. On this basis, this study investigated the possibility of concentrating metals from old wasted printed circuit boards through a physical separation-based route. Preparation of samples comprised fragmentation, size classification, density, and magnetic separation steps, followed by chemical and macro composition analysis. Cu, Al, Fe, and Sn constituted the major metals encountered in the scraps, including some peak concentrations of Zn, Sb, Pb, Ba, and Mn. Four distinct concentrate products could be obtained after suitable processing: (a) a light fraction composed of plastics and resins; (b) an aluminum concentrate; (c) a magnetic material concentrate, containing mainly iron; (d) a final concentrate containing more than 50% in mass of copper and enriched with nonferrous metals. Preliminary evidence showed that further processes, like the separation of copper wires through drumming, can potentially improve the effectiveness of the proposed processing circuit and should guide future works.

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COPPER AND LEAD RECOVERY FROM DISCARDED PRINTED CIRCUIT BOARDS BY ELECTROLYSING LEACHED SOLUTION

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/55/1b/12100 ◽

2018 ◽

Vol 55 (1B) ◽

pp. 129

Author(s):

Tran Thi Phuong Thao

Keyword(s):

Printed Circuit Boards ◽

Recovery Process ◽

Xrd Analysis ◽

Composition Analysis ◽

Copper Electrodeposition ◽

Circuit Boards ◽

Printed Circuit ◽

Electrochemical Parameters ◽

Lead Recovery ◽

Acidic Dissolution

Results of copper and lead recovery from discarded printing circuit boards (PCB) by acidic dissolution and electrodeposition are presented. A preliminary procedure of the recovery process is proposed with the following steps: disposal of the mounted electrical elements, cleaning, grinding, iron separation for grains screening, metal dissolution, and electrolysis. The composition analysis is performed to define suitable electrochemical parameters for recovery. XRF and AAS techniques are used for preliminary estimation of metal content in leached solution. LSV method is implemented to establish parameters for copper electrodeposition. The product quality is evaluated through XRD analysis. The high recovery efficiencies, 97.61% and 96.59 % for copper (in metallic form) and lead (in dioxide form), respectively, were reached.

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Study on the characteristics of centrifugal separation process of the solder on the waste printed circuit boards

Water Resources and Environment ◽

10.1201/b19079-73 ◽

2015 ◽

pp. 439-443

Author(s):

R Wang ◽

X Zhou ◽

X Xing ◽

X Wan

Keyword(s):

Printed Circuit Boards ◽

Separation Process ◽

Centrifugal Separation ◽

Circuit Boards ◽

Printed Circuit ◽

Waste Printed Circuit Boards

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Simulation of Corona Electrostatic Separator for End-of-Life Management in Printed Circuit Boards

10.1115/detc2021-71447 ◽

2021 ◽

Author(s):

Trunal Patil ◽

Lara Rebaioli ◽

Irene Fassi

Keyword(s):

End Of Life ◽

Process Parameters ◽

Printed Circuit Boards ◽

Separation Process ◽

Circuit Boards ◽

Electrostatic Separation ◽

Printed Circuit ◽

Life Management ◽

Electrostatic Separator ◽

Particles Trajectories

Abstract Printed circuit boards (PCBs) are made of several materials, including platinum, gold, silver, and rare earth elements, which are very valuable from a circular economy perspective. The PCB end of life management starts with the component removal, then the PCBs are shredded into small particles. Eventually, different separation methods are applied to the pulverized material to separate metals and non-metals. The corona electrostatic separation is one of the methods that can be used for this purpose since it is able to separate the conductive and non-conductive materials. However, the lack of knowledge to set the process parameters may affect the efficiency of the corona electrostatic separation process, ultimately resulting in the loss of valuable materials. The simulation of particle trajectory can be very helpful to identify the effective process parameters of the separation process. Thus, in this study, a simulation model to predict the particles trajectories in a belt type corona electrostatic separator is developed with the help of COMSOL Multiphysics and MATLAB software. The model simulates the particle behavior taking into account the electrostatic, gravitational, centrifugal, electric image, and air drag forces. Moreover, the predicted particles trajectories are used to analyze the effects of the roll electrode voltage, angular velocity of roll electrode, and size of the particles on the separation process.

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Enrichment of the metallic components from waste printed circuit boards by a mechanical separation process using a stamp mill

Waste Management ◽

10.1016/j.wasman.2008.06.035 ◽

2009 ◽

Vol 29 (3) ◽

pp. 1132-1137 ◽

Cited By ~ 119

Author(s):

Jae-Min Yoo ◽

Jinki Jeong ◽

Kyoungkeun Yoo ◽

Jae-chun Lee ◽

Wonbaek Kim

Keyword(s):

Printed Circuit Boards ◽

Separation Process ◽

Circuit Boards ◽

Printed Circuit ◽

Waste Printed Circuit Boards ◽

Mechanical Separation

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INVESTIGATION OF ABILITY LIBERATION OF METALS FROM PRINTED CIRCUIT BOARDS BY MECHANICAL PROCESSES FOR PHYSICAL SEPARATION PROCESSES

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/54/2a/11936 ◽

2018 ◽

Vol 54 (2A) ◽

pp. 237

Author(s):

Ha Vinh Hung

Keyword(s):

Printed Circuit Boards ◽

Separation Efficiency ◽

Low Cost ◽

Separation Process ◽

Air Separation ◽

Hammer Mill ◽

Circuit Boards ◽

Metallic Component ◽

Physical Separation ◽

Printed Circuit

Physical separation process was widely applied for the separation of metallic component from Printed Circuit Boards (PCBs) due to their advantages as friendly-environment, facilitated control, and low-cost. However, the efficiency of physical separation depends on a level of the liberation between the metallic and non-metallic components which is conducted by mechanical processing.In this study, the liberation of metals from computer PCBs was conducted in detail by mechanical processes including cutting and crushing. The obtained results demonstrate the distribution metallic and non-metallic component weighs as a function of particle sizes. The separation efficiency of metals was conducted by air separation using vacuum sorter equipment. The results showed that the comminution processes using hammer mill for reach the highest efficiency with 92 % recovery and 87 % grade of metallic components in the heavy fraction with particle size 1.0 - 1.4 mm by air separation process.

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