Novel physical separation process for eco-friendly recycling of rare and valuable metals from end-of-life DVD-PCBs

2013 ◽  
Vol 111 ◽  
pp. 145-154 ◽  
Author(s):  
Vinod Kumar ◽  
Jae-chun Lee ◽  
Jinki Jeong ◽  
Manis Kumar Jha ◽  
Byung-su Kim ◽  
...  
RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24132-24136
Author(s):  
Liurui Li ◽  
Tairan Yang ◽  
Zheng Li

The pre-treatment efficiency of the direct recycling strategy in recovering end-of-life Li-ion batteries is predicted with levels of control factors.


2020 ◽  
Vol 38 (11) ◽  
pp. 1214-1221
Author(s):  
Yuhui Zhang ◽  
Xiaoyan Feng ◽  
Bingjie Jin

Separation of arsenic and valuable metals (Pb, Zn, Cu, Bi, Sn, In, Ag, Sb, etc.) is a core problem for effective utilization of high arsenic-containing copper smelting ashes (HACSA). This study developed an effective separation process of arsenic, lead, and zinc from HACSA via alkali leaching followed by sulfide precipitation. The separation behaviors and optimum conditions for alkali leaching of arsenic and sulfide precipitation of lead and zinc were established respectively as follows: NaOH concentration 3.81 M; temperature 80°C; time 90 minutes; liquid-to-solid ratio 4:1; agitation speed 450 revolutions/minute (r/min) and 2.0 times of theoretical quantity of sodium sulfide (Na2S); temperature 70°C; and time 60 minutes. The results indicated that the leaching rates of As, Pb, and Zn were 92.4%, 36.9% and 13.4%, respectively. More than 99% of lead and zinc were precipitated from the alkali leachate. The scanning electron microscopy/energy dispersive X-ray spectroscopy study confirmed that arsenic was dissolved from HACSA into the alkali leachate. Furthermore, lead and zinc were precipitated as sulfides from the alkali leachate. The proposed process was a good technique for separation of arsenic and enrichment of valuable metals for further centralized treatment separately. It provided high separation efficiency of arsenic and valuable metals, as well as low environmental pollution.


Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 879
Author(s):  
Beom-Uk Kim ◽  
Chul-Hyun Park

There is increasing demand for an efficient technique for separating automobile shredder residue (ASR) obtained from end-of-life vehicles (ELVs). A particular challenge is the physical separation of conductive materials from glass. In this study, the performance of pretreatment and induction electrostatic separation process was evaluated. The results show that a sieving/washing (combination of sieving and washing) pretreatment was the most effective for removing conductive material compared to electrostatic separation alone. The optimum separation efficiency of copper products was achieved with an applied voltage of 20 kV, a relative humidity of less than 35%, and a splitter position of 8 cm. Although the separation efficiency was slightly reduced when some small glass particles remained attached to the conductive materials, the separation efficiency of copper from the pretreated ASR dramatically increased to 83.1% grade and 90.4% recovery, compared to that of raw ASR (34.3% grade and 58.6% recovery). Based on these results, it was demonstrated that the proposed sieving/washing pretreatment was proficient at removing conductive materials from glass; thus, it has the potential to significantly improve the efficiency of electrostatic separation for ASR.


2020 ◽  
Vol 6 (3) ◽  
pp. 25-42
Author(s):  
Nay Zaw Htay Win ◽  
◽  
Apisit Numprasanthai ◽  
Pipat Laowattanabandit ◽  
◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1504
Author(s):  
Tlotlo Solomon Gabasiane ◽  
Gwiranai Danha ◽  
Tirivaviri A. Mamvura ◽  
Tebogo Mashifana ◽  
Godfrey Dzinomwa

Copper slag is generated when copper and nickel ores are recovered from their parent ores using a pyrometallurgical process, and these ores usually contain other elements which include iron, cobalt, silica, and alumina. Slag is a major problem in the metallurgical industries as it is dumped into heaps which have accumulated into millions of tons over the years. Moreover, they pose a danger to the environment as they occupy vacant land (space problems). Over the past few years, studies have been conducted to investigate the copper slag-producing outlets to learn their behavior, as well as properties of slag, to have the knowledge of how to better reuse and recycle copper slag. This review article provides the environmental and socioeconomic impacts of slag, as well as a characterization of copper slag, with the aim of reusing and recycling the slag to benefit the environment and economy. Recycling methods are considered an attractive technological pathway for reducing waste and greenhouse gas emissions, as well as promoting the concept of circular economy through the utilization of waste. These metal elements have value depending on their characteristics; hence, copper slag is considered as a secondary source of valuable metals. Some of the pyrometallurgical and hydrometallurgical processes to consider are physical separation, magnetic separation, flotation, leaching, and direct reduction roasting of iron (DRI). Some of the possible metals that can be recovered from the copper slag include Cu, Fe, Ni, Co, and Ag (precious metals).


2021 ◽  
Author(s):  
Trunal Patil ◽  
Lara Rebaioli ◽  
Irene Fassi

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.


2022 ◽  
pp. 103680
Author(s):  
Haiqing Li ◽  
Chairun Nasirin ◽  
Azher M. Abed ◽  
Dmitry Olegovich Bokov ◽  
Lakshmi Thangavelu ◽  
...  

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