Quo Vadis Recycling 6

A special issue of Recycling (ISSN 2313-4321).

Deadline for manuscript submissions: closed (30 September 2017) | Viewed by 47474

Special Issue Editor


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Guest Editor
Institute of Recycling Technologies, Faculty of Materials, Metallurgy and Recycling, Technical University of Košice, Letná 9, 042 00 Kosice, Slovakia
Interests: waste treatment; recycling; municipal waste; industrial waste; hydrometallurgy; non-ferrous metals
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Special Issue Information

Dear Colleagues,

The focus of this Special Issue is on the field of material recycling, recycling technologies, recovery of valuable components, waste minimization, and the safe disposal of wastes. The international conference, “Quo Vadis Recycling 6”, mainly focuses on the exchange of knowledge and experience in the area of pre-treatment, sampling, handling, processing and material recycling of wastes and secondary raw materials, as well as their theoretical, practical, environmental, economic, and legislative aspects. Special attention was also paid to critical raw materials, circular economy, and recovery of metals from wastes. Obviously, waste has to be treated according to the law. Very often, it is taken as a valuable secondary raw material.  There are also some advantages compared to primary raw materials when material recycling is applied. The EU waste hierarchy will apply, as a priority order in waste prevention and management legislation and policy: (a) prevention, (b) preparing for re-use, (c) recycling, (d) other recovery, e.g., energy recovery, and (e) disposal. This means that, according to waste law, we have forced discipline for maximum exploitation of waste constituent before its disposal. Although the raw materials are essential for the European Union’s economy, their availability is increasingly under pressure. It was decided to identify a list of critical raw materials at the European Union level, and the concept of their criticality was determined. The strategy of the European Union is based on three pillars, namely: (1) ensure a level playing field in the access to resources in third world; (2) foster a sustainable supply from European sources; and (3) boost resource efficiency and recycling. The international conference, “Quo Vadis Recycling 6”, offers the opportunity for further development in all aspects of the field of waste recycling, and to follow up on the principles of sustainability, resource management, and circular economy.

Dr. Dusan Orac
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Recycling is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Recycling
  • Municipal Solid Waste
  • Industrial Waste
  • Hazardous Waste
  • Wastewater
  • Biological Waste
  • Critical Raw Materials and Critical Metals
  • Sampling and Assaying of Waste
  • Waste Management and Legislation
  • Circular Economy
  • Design of Recycling Facilities and Plants
  • Software products for recycling

Published Papers (5 papers)

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6973 KiB  
Article
Hydrocyclone Separation of Hydrogen Decrepitated NdFeB
by Muhammad Awais, Fernando Coelho, Malik Degri, Enrique Herraiz, Allan Walton and Neil Rowson
Recycling 2017, 2(4), 22; https://doi.org/10.3390/recycling2040022 - 14 Nov 2017
Cited by 9 | Viewed by 6174
Abstract
Hydrogen decrepitation (HD) is an effective and environmentally friendly technique for recycling of neodymium-iron-boron (NdFeB) magnets. During the HD process, the NdFeB breaks down into a matrix phase (Nd2Fe14BHx) and RE-rich grain boundary phase. The grain boundary [...] Read more.
Hydrogen decrepitation (HD) is an effective and environmentally friendly technique for recycling of neodymium-iron-boron (NdFeB) magnets. During the HD process, the NdFeB breaks down into a matrix phase (Nd2Fe14BHx) and RE-rich grain boundary phase. The grain boundary phase in the HD powder is <2 μm in size. Recycled NdFeB material has a higher oxygen content compared to the primary source material. This additional oxygen mainly occurs at the Rare Earth (RE) rich grain boundary phase (GBP), because rare earth elements oxidise rapidly when exposed to air. This higher oxygen level in the material results in a drop in density, coercivity, and remanence of sintered NdFeB magnets. The particle size of the GBP is too small to separate by sieving or conventional screening technology. In this work, an attempt has been made to separate the GBP from the matrix phase using a hydrocyclone, and to optimise the separation process. HD powder, obtained from hard disk drive (HDD) scrap NdFeB sintered magnets, was used as a starting material and passed through a hydrocyclone a total number of six times. The X-ray fluorescence (XRF) analysis and sieve analysis of overflows showed the matrix phase had been directed to the underflow while the GBP was directed to the overflow. The optimum separation was achieved with three passes. Underflow and overflow samples were further analysed using an optical microscope and MagScan and matrix phase particles were found to be magnetic. Full article
(This article belongs to the Special Issue Quo Vadis Recycling 6)
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1556 KiB  
Article
Leaching of Metals from Spent Lithium-Ion Batteries
by Miamari Aaltonen, Chao Peng, Benjamin P. Wilson and Mari Lundström
Recycling 2017, 2(4), 20; https://doi.org/10.3390/recycling2040020 - 31 Oct 2017
Cited by 76 | Viewed by 14784
Abstract
The recycling of valuable metals from spent lithium-ion batteries (LIBs) is becoming increasingly important due to the depletion of natural resources and potential pollution from the spent batteries. In this work, different types of acids (2 M citric (C6H8O [...] Read more.
The recycling of valuable metals from spent lithium-ion batteries (LIBs) is becoming increasingly important due to the depletion of natural resources and potential pollution from the spent batteries. In this work, different types of acids (2 M citric (C6H8O7), 1 M oxalic (C2H2O4), 2 M sulfuric (H2SO4), 4 M hydrochloric (HCl), and 1 M nitric (HNO3) acid)) and reducing agents (hydrogen peroxide (H2O2), glucose (C6H12O6) and ascorbic acid (C6H8O6)) were selected for investigating the recovery of valuable metals from waste LIBs. The crushed and sieved material contained on average 23% (w/w) cobalt, 3% (w/w) lithium, and 1–5% (w/w) nickel, copper, manganese, aluminum, and iron. Results indicated that mineral acids (4 M HCl and 2 M H2SO4 with 1% (v/v) H2O2) produced generally higher yields compared with organic acids, with a nearly complete dissolution of lithium, cobalt, and nickel at 25 °C with a slurry density of 5% (w/v). Further leaching experiments carried out with H2SO4 media and different reducing agents with a slurry density of 10% (w/v) show that nearly all of the cobalt and lithium can be leached out in sulfuric acid (2 M) when using C6H8O6 as a reducing agent (10% g/gscraps) at 80 °C. Full article
(This article belongs to the Special Issue Quo Vadis Recycling 6)
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602 KiB  
Communication
Primary Copper Smelter and Refinery as a Recycling Plant—A System Integrated Approach to Estimate Secondary Raw Material Tolerance
by Olof Forsén, Jari Aromaa and Mari Lundström
Recycling 2017, 2(4), 19; https://doi.org/10.3390/recycling2040019 - 24 Oct 2017
Cited by 37 | Viewed by 14865
Abstract
The primary production of sulfide concentrates includes smelting to copper matte or blister copper, conversion of matte to blister copper, and refining to copper. Smelting, converting, and fire-refining can use a limited amount of secondary materials. Molten copper can effectively dissolve many metals, [...] Read more.
The primary production of sulfide concentrates includes smelting to copper matte or blister copper, conversion of matte to blister copper, and refining to copper. Smelting, converting, and fire-refining can use a limited amount of secondary materials. Molten copper can effectively dissolve many metals, from valuable noble metals to harmful impurities such as bismuth. However, some of the impurity metals in copper are valuable in other applications. In this paper, we outline the main material flows in copper smelting and electrorefining and describe how minor metals can be recovered from secondary raw materials using copper as a carrier material. We will use a system integrated approach to define the factors that affect the recovery of different metals and copper quality. Metals typical in copper production are used as examples, like noble metals, As, Bi, Se, and Te, including metals in the EU critical raw materials list like PGM and Sb. Full article
(This article belongs to the Special Issue Quo Vadis Recycling 6)
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1674 KiB  
Article
The Effect of the Redox Potential of Aqua Regia and Temperature on the Au, Cu, and Fe Dissolution from WPCBs
by Heini Elomaa, Sipi Seisko, Tero Junnila, Tuomas Sirviö, Benjamin P. Wilson, Jari Aromaa and Mari Lundström
Recycling 2017, 2(3), 14; https://doi.org/10.3390/recycling2030014 - 01 Sep 2017
Cited by 17 | Viewed by 7731
Abstract
Constant growth in waste electrical and electronic equipment (WEEE) levels necessitates the development of new, commercially viable recycling processes. Waste printed circuit boards (WPCBs) are a sub-group of WEEE that are of increasing interest due to their relatively high level of valuable metal [...] Read more.
Constant growth in waste electrical and electronic equipment (WEEE) levels necessitates the development of new, commercially viable recycling processes. Waste printed circuit boards (WPCBs) are a sub-group of WEEE that are of increasing interest due to their relatively high level of valuable metal content including Au, Ag, and platinum group metals (PGMs). Currently, precious metals like gold are mainly recycled from WEEE streams through copper smelting/refining; however, the possibility to peel gold from WPCBs prior to smelting, could offer advantages for recycling. In this study, the suitability of aqua regia for selective or partially selective gold leaching from un-crushed WPCBs was investigated. The redox potential of aqua regia solutions and the dissolution efficiencies of Au, Cu, and Fe from WPCBs were investigated at different temperatures (40–80 °C) and concentrations (2–32%) in batch leaching tests. The redox potential of aqua regia solution was found to depend on concentration and temperature. It is suggested that Au dissolution in aqua regia requires dissolved Cu2+ ions originating from the WPCB material to work. Au extraction (>50%) was shown to require a redox potential >700 mV with [Cu2+] > 2500 ppm, as a potential >850 mV alone was insufficient without cupric ions. Significant amounts of Au and Cu could be dissolved with only minor Fe dissolution at ≥8% aqua regia at 80 °C. Results suggest that leaching of uncrushed WPCBs in 8% aqua regia (T = 80 °C) can provide the opportunity for partial Au recovery prior to further processing. Full article
(This article belongs to the Special Issue Quo Vadis Recycling 6)
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12 pages, 3479 KiB  
Technical Note
Research of Chosen Acoustics Descriptors of Developed Materials from Old Automobile Recycled Materials
by Miroslav Badida, Lydia Sobotova, Anna Badidova, Marek Moravec and Alzbeta Mikulova
Recycling 2018, 3(2), 29; https://doi.org/10.3390/recycling3020029 - 14 Jun 2018
Viewed by 3434
Abstract
Legislative regulations and standards have been approved for noise control, aimed at controlling noise minimization. This problem is also under the public interest, because noise is increasing in many counties. EU directive 70/157/eec determines and controls limits of environmental noise and is aimed [...] Read more.
Legislative regulations and standards have been approved for noise control, aimed at controlling noise minimization. This problem is also under the public interest, because noise is increasing in many counties. EU directive 70/157/eec determines and controls limits of environmental noise and is aimed at creating less noisy and more pleasant outdoor and indoor environments for European residents within “sustainable development in Europe”. This study focused on the utilization of new, so-called acoustic more convenient materials, based on and produced from old materials from automobiles, e.g. foam, textile, rubber, and tires. The chosen acoustic parameters—sound absorption coefficient and sound transmission loss—of these materials were tested, and the acoustic properties of materials were subsequently improved compared to tested values and potential applications for them were found. Full article
(This article belongs to the Special Issue Quo Vadis Recycling 6)
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