Submit to Materials Review for Materials Propose a Special Issue

Journal Browser

Metallurgy of Non-ferrous, Rare and Precious Metals

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Manufacturing Processes and Systems".

Deadline for manuscript submissions: closed (20 April 2022) | Viewed by 35424

Share This Special Issue

Special Issue Editor

Prof. Dr. Alexander A. Gromov

E-Mail Website
Guest Editor

MISIS Catalysis Laboratory, National University of Science and Technology MISIS, 119991 Moscow, Russia
Interests: additive manufacturing; metals; oxidation; combustion; powders
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Modern metallurgy of non-ferrous, rare, and precious metals in 21st century has progressed significantly from the end of 19th century, when the metallurgical processes of, say, aluminum production were so expensive that French Emperor Napoleon III ate off of aluminum plates, while the gold and silver ones were served for his guests. However, a lot of energy is still required for the metallurgy of non-ferrous, rare, and precious metals. The trend of energy saving for this field is of primary importance. Another important problem is implification of the new fast and energy saving methods and high-tech devises made of non-ferrous metals production: additive manufacturing for the complex-shape articles, micron-sized and nanometal powders production, characterization, application and modern powder metallurgy, new sintering and processing methods like spark plasma sintering (SPS), self-propagated high-temperature synthesis (SHS), mechanical alloying and mechanosynthesis etc. The above mentioned processes of innovative metallurgy will be covered in this Special Issue. The problems of secondary non-ferrous metal raw materials treatment will be are also of interest. The amount of accumulated non-ferrous metallic wastes on our planet are billion tons recently. Thus, the ecological aspects of their utilization and re-use requires special attention and will be one of the topic for this Special Issue.

Prof. Alexander Alexandrovich Gromov
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. Materials 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 2600 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

non-ferrous
rare and precious metals
powder metallurgy
metal wastes
SPS, SHS
metallic wastes

Published Papers (10 papers)

Download All Papers

Research

11 pages, 1685 KiB

Open AccessArticle

Refining of Precious Metal Bearing Materials from Secondary Sources-Methanesulfonic Acid Leaching of Raw Silver Granules as a Promising Approach towards a Green Way of Silver Refining

by Johannes Hopf, Aaron Weigelt, Hartmut Bombach, Michael Stelter and Alexandros Charitos

Materials 2021, 14(20), 6095; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14206095 - 15 Oct 2021

Cited by 1 | Viewed by 1769

Abstract

The state-of-the-art technology of raw silver refining in a silver nitrate-based electrorefining process (Moebius-electrolysis) is accompanied by several disadvantages, both from a technological and from an ecological point of view. In addition, increasing concentrations of critical impurities from secondary sources, like palladium, in raw silver are a further challenge for the future of silver refining. Thus, there is strong motivation for the development of an adequate, alternative process of raw silver refining to substitute the existing Moebius-electrolysis. Due to its less environmentally toxic character and the high aqueous solubility of its silver salt, methanesulfonic acid (MSA) is a possible base chemical for the design of an efficient refining method based on leaching of raw silver followed by electrowinning, with less ecological and technological complications. In this paper the results of some fundamental investigations on the leaching of raw silver granules, containing approx. 94% silver, with methanesulfonic acid and hydrogen peroxide as an oxidation agent are presented. Agitation leaching experiments were conducted on a laboratory scale and the effects of the solid concentration, the hydrogen peroxide dosage and the temperature as leaching parameters were studied. The obtained results indicate that silver leaching yields of more than 90% are achievable with leaching at elevated temperatures of 65 °C or 80 °C, solid concentrations of 500 g/L and at a stoichiometric H₂O₂:Ag-ratio of 3:1. Increased solid concentrations greater than 500 g/L and elevated temperatures of 65 °C or 80 °C additionally improved the selectivity of the process regarding the leaching of Pd. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

28 pages, 10440 KiB

Open AccessArticle

Comprehensive Study on the Mechanism of Sulfating Roasting of Zinc Plant Residue with Iron Sulfates

by Pavel Grudinsky, Denis Pankratov, Dmitry Kovalev, Darya Grigoreva and Valery Dyubanov

Materials 2021, 14(17), 5020; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14175020 - 02 Sep 2021

Cited by 8 | Viewed by 3040

Abstract

Zinc plant residue (ZPR) is a secondary material generated during hydrometallurgical zinc production that contains considerable contents of valuable elements such as Zn, Cu, Fe, Pb, Cd, Ag, In, Ga, Tl. Zinc, copper and accompanying elements in ZPR are in different minerals, mainly in the ferrites. A promising approach for recycling ZPR is the sulfating roasting using iron sulfates followed by water leaching. In this study, the composition of ZPR and the obtained products were thoroughly investigated by various methods including X-ray diffraction analysis (XRD), chemical phase analysis and Mössbauer spectroscopy. The effect of temperature, amount of iron sulfates and roasting time on the conversion of valuable metals into a water-soluble form was thermodynamically and experimentally studied both using pure ferrites and ZPR. Based on the results of time-resolved XRD analysis and synchronous thermal analysis (STA), a mechanism of the sulfation roasting was elucidated. The rate-controlling step of zinc and copper sulfation process during the ZPR roasting was estimated. The sulfating roasting at 600 °C during 180 min with the optimal Fe₂(SO₄)₃∙9H₂O addition followed by water leaching enables to recover 99% Zn and 80.3% Cu, while Fe, Pb, Ag, In, Ga retained almost fully in the residue. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Graphical abstract

17 pages, 8161 KiB

Open AccessArticle

Structure, Morphology, Heat Capacity, and Electrical Transport Properties of Ti₃(Al,Si)C₂ Materials

by Kamil Goc, Janusz Przewoźnik, Katarzyna Witulska, Leszek Chlubny, Waldemar Tokarz, Tomasz Strączek, Jan Marek Michalik, Jakub Jurczyk, Ivo Utke, Jerzy Lis and Czesław Kapusta

Materials 2021, 14(12), 3222; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14123222 - 11 Jun 2021

Cited by 5 | Viewed by 2642

Abstract

A study of Ti₃Al_1−xSi_xC₂ (x = 0 to x = 1) MAX-phase alloys is reported. The materials were obtained from mixtures of Ti₃AlC₂ and Ti₃SiC₂ powders with hot [...] Read more.

A study of Ti₃Al_1−xSi_xC₂ (x = 0 to x = 1) MAX-phase alloys is reported. The materials were obtained from mixtures of Ti₃AlC₂ and Ti₃SiC₂ powders with hot pressing sintering technique. They were characterised with X-ray diffraction, heat capacity, electrical resistivity, and magnetoresistance measurements. The results show a good quality crystal structure and metallic properties with high residual resistivity. The resistivity weakly varies with Si doping and shows a small, positive magnetoresistance effect. The magnetoresistance exhibits a quadratic dependence on the magnetic field, which indicates a dominant contribution from open electronic orbits. The Debye temperatures and Sommerfeld coefficient values derived from specific heat data show slight variations with Si content, with decreasing tendency for the former and an increase for the latter. Experimental results were supported by band structure calculations whose results are consistent with the experiment concerning specific heat, resistivity, and magnetoresistance measurements. In particular, they reveal that of the s-electrons at the Fermi level, those of Al and Si have prevailing density of states and, thus predominantly contribute to the metallic conductivity. This also shows that the high residual resistivity of the materials studied is an intrinsic effect, not due to defects of the crystal structure. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

11 pages, 32059 KiB

Open AccessArticle

Particle Image Velocimetry Method for Prediction Hydrodynamic Conditions during Leaching Process on the Basis of Sn–NaOH System

by Adam Cwudziński and Bernadeta Gajda

Materials 2021, 14(3), 633; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14030633 - 29 Jan 2021

Cited by 1 | Viewed by 1417

Abstract

In leaching processes controlled by diffusion and convectional transport of mass, the hydrodynamic structure formed in the reactor’s working volume is an additional factor affecting the process. This research work presents results related to hydrodynamic structures developing in batch reactors, different in shape, recorded by means of the particle image velocimetry (PIV) method. The movement of the distilled water and leaching solution was analyzed during investigations. Next, the system hydrodynamics and the process of tin leaching were analyzed. Finally, the leaching is affected by the reactor geometry and the hydrodynamic structure developed in its working volume, especially when a convectional or diffusion mass transport decides the process efficiency. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

14 pages, 5226 KiB

Open AccessArticle

Metal Nanoparticles Formation from Nickel Hydroxide

by Elena N. Sidorova, Ella L. Dzidziguri, Yulia P. Vinichenko, Dmitriy Yu. Ozherelkov, Alexander S. Shinkaryov, Alexander A. Gromov and Anton Yu. Nalivaiko

Materials 2020, 13(20), 4689; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13204689 - 21 Oct 2020

Cited by 7 | Viewed by 3072

Abstract

In this study, the mechanism of nickel nanoparticle formation from its hydroxide was analyzed. Metallic nickel nanoparticles were obtained through the hydroxide’s reduction under hydrogen. Nickel hydroxides were produced from nickel (II) nitrate hexahydrate and NaOH by deposition under various initial conditions. The influence of washing treatment on the dispersion of obtained nickel powders was studied. The washing procedure of precipitates was carried out by centrifugation, ultrasonic treatment, and decantation. X-ray diffractometry, transmission electron microscopy, low-temperature nitrogen adsorption, infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy methods were used for nanoparticle characterization. Based on the resulting data, a model of the Ni(OH)₂ aggregate structure after deposition was proposed. The number of nickel hydroxide particles required to form one nickel nanoparticle was estimated, and a model of its formation was proposed. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

12 pages, 6168 KiB

Open AccessArticle

Obtaining Alumina from Kaolin Clay via Aluminum Chloride

by Vyacheslav I. Pak, Sergey S. Kirov, Anton Yu. Nalivaiko, Dmitriy Yu. Ozherelkov and Alexander A. Gromov

Materials 2019, 12(23), 3938; https://0-doi-org.brum.beds.ac.uk/10.3390/ma12233938 - 28 Nov 2019

Cited by 23 | Viewed by 4676

Abstract

A method of alumina production based on hydrochloric acid processing of kaolin clays from the East Siberian deposits was studied. Hydrochloric acid leaching was carried out at 160 °C. The leaching solution was subjected to a two-stage crystallization of aluminum chloride hexahydrate (ACH). The precipitated crystals were calcinated in air at a temperature above 800 °C to produce alumina. The main part of water and chlorine during thermal decomposition of ACH was removed at 400 °C. The influence of temperature and duration of ACH calcination on the residual chlorine content in alumina was studied. The optimal temperature of ACH calcination was 900 °C with a duration of 90 min. It was shown that the increase in calcination temperature contributed to the decrease in chlorine content in the final product. However, an increase in calcination temperature above 900 °C led to the transition of the well-soluble γ-Al₂O₃ phase to the insoluble α-Al₂O₃, which negatively affected the further electrolysis of aluminum. The size of alumina particles was not affected by the calcination mode. The rate of dissolution of the prototype Al₂O₃ in Na₃AlF₆ was higher than for the alumina obtained by the classical method. Alumina content, particle morphology, and particle size distribution for the obtained alumina were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser diffraction methods. The obtained alumina is suitable for aluminum production according to the studied characteristics. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

16 pages, 7891 KiB

Open AccessFeature PaperArticle

Possibilities of Manufacturing Products from Cermet Compositions Using Nanoscale Powders by Additive Manufacturing Methods

by Sergei Grigoriev, Tatiana Tarasova, Andrey Gusarov, Roman Khmyrov and Sergei Egorov

Materials 2019, 12(20), 3425; https://0-doi-org.brum.beds.ac.uk/10.3390/ma12203425 - 19 Oct 2019

Cited by 27 | Viewed by 3237

Abstract

Complicated wear-resistant parts made by selective laser melting (SLM) of powder material based on compositions of metal and ceramics can be widely used in mining, oil engineering, and other precision engineering industries. Ceramic–metal compositions were made using nanoscale powders by powder metallurgy methods. Optimal regimes were found for the SLM method. Chemical and phase composition, fracture toughness, and wear resistance of the obtained materials were determined. The wear rate of samples from 94 wt% tungsten carbide (WC) and 6 wt% cobalt (Co) was 1.3 times lower than that of a sample from BK6 obtained by the conventional methods. The hardness of obtained samples 2500 HV was 1.6 times higher than that of a sample from BK6 obtained by the traditional method (1550 HV). Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

11 pages, 4792 KiB

Open AccessArticle

Aluminum-Alumina Composites: Part I: Obtaining and Characterization of Powders

by Alexander A. Gromov, Anton Yu. Nalivaiko, Grayr N. Ambaryan, Mikhail S. Vlaskin, Olesya A. Buryakovskaya, Sergey A. Kislenko, Andrey Z. Zhuk, Evgeniy I. Shkolnikov, Konstantin V. Slyusarskiy, Alexandra A. Osipenkova and Alexey N. Arnautov

Materials 2019, 12(19), 3180; https://0-doi-org.brum.beds.ac.uk/10.3390/ma12193180 - 27 Sep 2019

Cited by 10 | Viewed by 5880

Abstract

The process of advanced aluminum-alumina powders production for selective laser melting was studied. The economically effective method of obtaining aluminum-alumina powdery composites for further selective laser melting was comprehensively studied. The aluminum powders with 10–20 wt. % alumina content were obtained by oxidation of aluminum in water. Aluminum oxidation was carried out at ≤200 °C. The oxidized powders were further dried at 120 °C and calcined at 600 °C. Four oxidation modes with different process temperatures (120–200 °C) and pressures (0.15–1.80 MPa) were investigated. Parameters of aluminum powders oxidation to obtain composites with 10.0, 14.5, 17.4, and 20.0 wt. % alumina have been determined. The alumina content, particle morphology, and particle size distribution for the obtained aluminum-alumina powdery composites were studied by XRD, SEM, laser diffraction, and volumetric methods. According to the obtained characteristics of aluminum-alumina powdery composites, they are suitable for the SLM process. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

14 pages, 4034 KiB

Open AccessArticle

Hydrometallurgical Process for Tantalum Recovery from Epoxy-Coated Solid Electrolyte Tantalum Capacitors

by Wei-Sheng Chen, Hsing-Jung Ho and Kuan-Yan Lin

Materials 2019, 12(8), 1220; https://0-doi-org.brum.beds.ac.uk/10.3390/ma12081220 - 14 Apr 2019

Cited by 26 | Viewed by 3970

Abstract

Tantalum is a critical metal that is widely used in electronic products. The demand for tantalum is increasing, but the supply is limited. As tantalum waste products have increased in Taiwan in recent years, the treatment of spent tantalum capacitors has become necessary and important. The recycling of tantalum from tantalum capacitors will not only decrease pollution from waste, but will also conserve tantalum resources. The tantalum content in epoxy-coated solid electrolyte tantalum capacitors (EcSETCs) is over 40 wt.%. Here, we designed a recycling process that includes pre-treatment, leaching, and solvent extraction to recover tantalum. In the pre-treatment process, epoxy resin and wires were removed. During hydrometallurgical process, pressure leaching by hydrofluoric acid was used to leach tantalum and manganese from solid electrolyte tantalum capacitors (SETCs). During our testing of this proposed process, the acid concentration, reaction time, temperature, and solid–liquid ratio were examined for leaching. After the leaching process, Alamine 336 was used to extract tantalum from the leaching solution. The pH value, extractant concentration, extraction time, and aqueous–organic ratio were investigated. Then, tantalum was stripped using HNO₃, and the HNO₃ concentration, stripping time, and organic–aqueous ratio were analyzed in detail. Under optimal conditions, the recovery efficiency of tantalum reached over 98%, and a final product of tantalum pentoxide with 99.9% purity was obtained after chemical precipitation and calcination. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

13 pages, 4264 KiB

Open AccessArticle

An Efficient Leaching of Palladium from Spent Catalysts through Oxidation with Fe(III)

by Yunji Ding, Huandong Zheng, Jiayi Li, Shengen Zhang, Bo Liu and Christian Ekberg

Materials 2019, 12(8), 1205; https://0-doi-org.brum.beds.ac.uk/10.3390/ma12081205 - 12 Apr 2019

Cited by 43 | Viewed by 3893

Abstract

Reclamation of spent catalysts for the efficient recovery of palladium (Pd) is gaining growing attention due to its scarcity and high supply risk. Currently Pd extraction from spent catalysts through an efficient, economical, and green method has remained a challenge. In this study, Fe³⁺ is utilized for leaching through oxidation of Pd in a mild condition. Before leaching, distillation was proposed to remove and recover the organics from spent catalysts. The effects of HCl concentration, Fe³⁺ concentration, NaCl concentration, leaching time, and temperature on the leaching efficiency of Pd were investigated to determine the optimum leaching conditions. The results show that Pd extraction and dissolution of Al₂O₃ increase with higher HCl concentration. The effect of NaCl on Pd leaching efficiency is significant at low acid concentration (2.0 mol/L HCl). The leaching efficiency was 99.5% for Pd under the following conditions: 2.0 mol/L HCl, 4.0 mol/L NaCl, and 0.67 mol/L Fe³⁺ at 80 °C for 90 min. The leaching kinetics fits best to the shrinking-core model of surface chemical reaction. The activation energy for the leaching of Pd was 47.6 kJ/mol. PdCl₄²⁻ was selectively adsorbed by anion exchange resin. The filtrate containing adequate H⁺, Cl^-, and Fe³⁺ was reused as leaching agent. Pd leaching efficiency was over 96% after five cycle times. This study provides an efficient process for recovery of Pd from spent catalysts. Full article

(This article belongs to the Special Issue Metallurgy of Non-ferrous, Rare and Precious Metals)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Metallurgy of Non-ferrous, Rare and Precious Metals

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (10 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI