scholarly journals The Global Metal Recycling Business, with a Focus on China

2006 ◽  
Vol 17 (2) ◽  
pp. 78-85
Author(s):  
Kazuaki Shimada
Keyword(s):  
2021 ◽  
pp. 0734242X2110039
Author(s):  
Huan Wang ◽  
Fenfen Zhu ◽  
Xiaoyan Liu ◽  
Meiling Han ◽  
Rongyan Zhang

This mini-review article summarizes the available technologies for the recycling of heavy metals (HMs) in municipal solid waste incineration (MSWI) fly ash (FA). Recovery technologies included thermal separation (TS), chemical extraction (CE), bioleaching, and electrochemical processes. The reaction conditions of various methods, the efficiency of recovering HMs from MSWI FA and the difficulties and solutions in the process of technical development were studied. Evaluation of each process has also been done to determine the best HM recycling method and future challenges. Results showed that while bioleaching had minimal environmental impact, the process was time-consuming. TS and CE were the most mature technologies, but the former process was not cost-effective. Overall, it has the greatest economic potential to recover metals by CE with scrubber liquid produced by a wet air pollution control system. An electrochemical process or solvent extraction could then be applied to recover HMs from the enriched leachate. Ongoing development of TS and bioleaching technologies could reduce the treatment cost or time.


2021 ◽  
Vol 13 (12) ◽  
pp. 6533
Author(s):  
Muhammad Nawaz ◽  
Muhammad Tariq Yousafzai ◽  
Tariq Shah ◽  
Chunlin Xin ◽  
Wisal Ahmad

This study assessed the role of waste picker sustainopreneurs (WPS) by examining their recycling contributions in a special case of District Swat, Pakistan. Using a transformative worldview, this study acknowledges their contributions to recycling. The study envisages how entrepreneurial agency works in unanticipated ways where the poorest of the poor enterprise without resources demonstrate unexpected agency to improve the environment. An inductive research design in conjunction with grounded theory was used to analyze data from 37 interviews in three tehsils of District Swat. The recycling sector uses primitive measures, which are completely informal, self-organized, and self-controlled. Surprisingly, we discovered that informal recycling contributes unfavorably to waste, energy, and food (WEF) security due to intermixing and adulteration, as well as acts as a gray channel for illicit practices that have taken advantage of tax amnesty in the area until 2023. The uncontrolled welding of half cut and nose cut car parts has skyrocketed the motorization index and CO2 emissions; however, it has also resulted in alternative sources of livelihoods, as these accidental environmentalists had found modern sources of income. This is similar to low-tech innovation and business creation that takes advantage of tax holidays due to the special status of District Swat. The study highlights the most and least valuable recyclables and identifies the gray channel markets of spare parts, metal recycling, counterfeit products, fuel intermixing, and adulteration. The study contributes by untangling the understanding of a legal gambit of tax amnesty at a critical pre-policy input as well as advocates for rights of invisible stakeholders of waste management in Pakistan.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4721
Author(s):  
Angela Serpe ◽  
Luca Pilia ◽  
Davide Balestri ◽  
Luciano Marchiò ◽  
Paola Deplano

In the context of new efficient and safe leaching agents for noble metals, this paper describes the capability of the Me2pipdt/I2 mixture (where Me2pipdt = N,N′-dimethyl-piperazine-2,3-dithione) in organic solutions to quantitatively dissolve Au, Pd, and Cu metal powders in mild conditions (room temperature and pressure) and short times (within 1 h in the reported conditions). A focus on the structural insights of the obtained coordination compounds is shown, namely [AuI2(Me2pipdt)]I3 (1), [Pd(Me2pipdt)2]I2 (2a) and [Cu(Me2pipdt)2]I3 (3), where the metals are found, respectively, in 3+, 2+ and 1+ oxidation states, and of [Cu(Me2pipdt)2]BF4 (4) and [Cu(Me2dazdt)2]I3 (5) (Me2dazdt = N,N′-dimethyl-perhydrodizepine-2,3-dithione) compared with 3. Au(III) and Pd(II) (d8 configuration) form square–planar complexes, whereas Cu(I) (d10) forms tetrahedral complexes. Density functional theory calculations performed on the cationic species of 1–5 help to highlight the nature of the bonding in the different complexes. Finally, the valorization of the noble metals-rich leachates is assessed. Specifically, gold metal is quantitatively recovered from the solution besides the ligands, showing the potential of these systems to promote metal recycling processes.


2021 ◽  
Author(s):  
Shuai D. Han ◽  
Baichuan Huang ◽  
Sijie Ding ◽  
Changkyu Song ◽  
Si Wei Feng ◽  
...  

2019 ◽  
Vol 232 ◽  
pp. 428-437 ◽  
Author(s):  
Romy Auerbach ◽  
Stefan Ratering ◽  
Katrin Bokelmann ◽  
Carsten Gellermann ◽  
Thilo Brämer ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document