Correction to “Recovery of Critical Metals from Aqueous Sources”

Considering economics and environmental sustainability, recycling of critical metals from end-of-life devices should be a priority. In this work the hydrometallurgical treatment of a spent automotive catalytic converter (SACC) using HCl with CaCl2 as a leaching medium, and solvent extraction (SX) with a thiodiglycolamide derivative, is reported. The aim was to develop a leaching scheme allowing high Pt recoveries and minimizing Al dissolution, facilitating the application of SX. The replacement of part of HCl by CaCl2 in the leaching step is viable, without compromising Pt recovery (in the range 75–85%), as found for the mixture 2 M CaCl2 + 8 M HCl when compared to 11.6 M HCl. All leaching media showed good potential to recover Ce, particularly for higher reaction times and temperatures. Regarding SX, results achieved with a model solution were promising, but SX for Pt separation from the real SACC solution did not work as expected. For the adopted experimental conditions, the tested thiodiglycolamide derivative in toluene revealed a very good loading performance for both Pt and Fe, but Fe removal and Pt stripping from the organic phases after contact with the SACC solution were not successfully accomplished. Hence, the reutilization of the organic solvent needs improvement.

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Evaluating critical metals contained in spintronic memory with a particular focus on Pt substitution for improved sustainability

Sustainable Materials and Technologies ◽

10.1016/j.susmat.2021.e00270 ◽

2021 ◽

Vol 28 ◽

pp. e00270

Author(s):

A. Palomino ◽

J. Marty ◽

S. Auffret ◽

I. Joumard ◽

R.C. Sousa ◽

...

Keyword(s):

Critical Metals

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Editorial for Special Issue “Critical Metals in Hydrothermal Ores: Resources, Recovery, and Challenges”

Minerals ◽

10.3390/min11030299 ◽

2021 ◽

Vol 11 (3) ◽

pp. 299

Author(s):

Lingli Zhou ◽

Hongrui Fan ◽

Thomas Ulrich

Keyword(s):

Technological Innovations ◽

Special Issue ◽

Critical Metals ◽

Continuous Growth ◽

Global Population

The consumption of resources has rapidly increased over the last few decades, driven by the continuous growth of the global population and technological innovations [...]

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Complex Concentrated Alloys for Substitution of Critical Raw Materials in Applications for Extreme Conditions

Materials ◽

10.3390/ma14051197 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1197

Author(s):

Dumitru Mitrica ◽

Ioana Cristina Badea ◽

Beatrice Adriana Serban ◽

Mihai Tudor Olaru ◽

Denisa Vonica ◽

...

Keyword(s):

Raw Materials ◽

Extreme Environment ◽

Extreme Conditions ◽

The European Union ◽

Critical Metals ◽

Research Directions ◽

Level Of Involvement ◽

General Evaluation ◽

Critical Metal ◽

Critical Raw Materials

The paper is proposing a mini-review on the capability of the new complex concentrated alloys (CCAs) to substitute or reduce the use of critical raw materials in applications for extreme conditions. Aspects regarding the regulations and expectations formulated by the European Union in the most recent reports on the critical raw materials were presented concisely. A general evaluation was performed on the CCAs concept and the research directions. The advantages of using critical metals for particular applications were presented to acknowledge the difficulty in the substitution of such elements with other materials. In order to establish the level of involvement of CCAs in the reduction of critical metal in extreme environment applications, a presentation was made of the previous achievements in the field and the potential for the reduction of critical metal content through the use of multi-component compositions.

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Rare and Critical Metals in Pyrite, Chalcopyrite, Magnetite, and Titanite from the Vathi Porphyry Cu-Au±Mo Deposit, Northern Greece

Minerals ◽

10.3390/min11060630 ◽

2021 ◽

Vol 11 (6) ◽

pp. 630

Author(s):

Christos L. Stergiou ◽

Vasilios Melfos ◽

Panagiotis Voudouris ◽

Lambrini Papadopoulou ◽

Paul G. Spry ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Mineral Chemistry ◽

Critical Metals ◽

Northern Greece ◽

Inductively Coupled ◽

Porphyry Cu ◽

Icp Ms ◽

Quartz Monzonite ◽

Ore Minerals ◽

Plasma Mass Spectrometry

The Vathi porphyry Cu-Au±Mo deposit is located in the Kilkis ore district, northern Greece. Hydrothermally altered and mineralized samples of latite and quartz monzonite are enriched with numerous rare and critical metals. The present study focuses on the bulk geochemistry and the mineral chemistry of pyrite, chalcopyrite, magnetite, and titanite. Pyrite and chalcopyrite are the most abundant ore minerals at Vathi and are related to potassic, propylitic, and sericitic hydrothermal alterations (A- and D-veins), as well as to the late-stage epithermal overprint (E-veins). Magnetite and titanite are found mainly in M-type veins and as disseminations in the potassic-calcic alteration of quartz monzonite. Disseminated magnetite is also present in the potassic alteration in latite, which is overprinted by sericitic alteration. Scanning electron microscopy and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of pyrite and chalcopyrite reveal the presence of pyrrhotite, galena, and Bi-telluride inclusions in pyrite and enrichments of Ag, Co, Sb, Se, and Ti. Chalcopyrite hosts bornite, sphalerite, galena, and Bi-sulfosalt inclusions and is enriched with Ag, In, and Ti. Inclusions of wittichenite, tetradymite, and cuprobismutite reflect enrichments of Te and Bi in the mineralizing fluids. Native gold is related to A- and D-type veins and is found as nano-inclusions in pyrite. Titanite inclusions characterize magnetite, whereas titanite is a major host of Ce, Gd, La, Nd, Sm, Th, and W.

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Polymetallic Nodules: Resource Potential and Mining Prospects

Marine Technology Society Journal ◽

10.4031/mtsj.55.6.8 ◽

2021 ◽

Vol 55 (6) ◽

pp. 22-30

Author(s):

Rahul Sharma

Keyword(s):

Deep Sea ◽

Environmental Issues ◽

Industrial Applications ◽

Green Energy ◽

Steady Increase ◽

Critical Metals ◽

Alternative Source ◽

Resource Potential ◽

Polymetallic Nodules ◽

International Seabed Authority

Abstract Deep-sea minerals such as polymetallic nodules have attracted significant interest among stakeholders not only for evaluating their potential as an alternative source of critical metals that are required for various industrial applications including green energy but also in developing technology for their exploitation. There has been a steady increase in the number of contractors having exploration rights over large tracts on the seafloor in the “Area,” and the International Seabed Authority that is mandated with the responsibility of regulating such activities is in the process of preparing a code for exploitation of these deep-sea minerals. This commentary takes a look at the resource potential and mining prospects of polymetallic nodules while addressing the economic and environmental issues associated with them.

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Research trend and dynamical development of focusing on the global critical metals: a bibliometric analysis during 1991–2020

Environmental Science and Pollution Research ◽

10.1007/s11356-021-17816-5 ◽

2021 ◽

Author(s):

Wei Liu ◽

Xin Li ◽

Minxi Wang ◽

Litao Liu

Keyword(s):

Bibliometric Analysis ◽

Research Trend ◽

Critical Metals

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Biogeochemistry of Critical Metals and the Flinders Ranges Natural Laboratory

10.46427/gold2020.273 ◽

2020 ◽

Author(s):

Joël Brugger ◽

Frank Reith ◽

Santonu Kumar Sanyal ◽

Jeremiah Shuster ◽

Barbara Etschmann

Keyword(s):

Critical Metals ◽

Flinders Ranges ◽

Natural Laboratory

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Preliminary Characterization of Three Metallurgical Bauxite Residue Samples

Materials Proceedings ◽

10.3390/materproc2021005066 ◽

2021 ◽

Vol 5 (1) ◽

pp. 66

Author(s):

Panagiotis Angelopoulos ◽

Maria Georgiou ◽

Paschalis Oustadakis ◽

Maria Taxiarchou ◽

Hakan Karadağ ◽

...

Keyword(s):

Low Cost ◽

Bauxite Residue ◽

Raw Material ◽

Morphological Observation ◽

Critical Metals ◽

Alumina Production ◽

Preliminary Characterization ◽

Fine Grained ◽

Extraction And Separation ◽

Bulk Chemical

Bauxite Metallurgical Residue (BR) is a highly alkaline and very fine-grained by-product of the Bayer process for alumina production. Its huge global annual production has resulted in increasing accumulation of BR, causing deposition problems and serious environmental issues. RM contains oxides and salts of the main elements Fe, Al, Ca, Na, Si, Ti, and rare earths—REEs (Sc, Nd, Y, La, Ce, Ds)—many of which have been categorised by EU as critical metals (CMs). The valorisation of BR as a low-cost secondary raw material and metal resource could be a route for its reduction, introducing the waste into the economic cycle. REEScue constitutes a research project that aims to instigate the efficient exploitation of European bauxite residues, resulting from alumina production from Greece (MYTILINEOS SA), Turkey (ETI Aluminium), and Romania (ALUM SA), containing appreciable concentrations of scandium and REEs, through the development of a number of innovative extraction and separation technologies that can efficiently address the drawbacks of the existing solution. The consortium consists of three alumina producers from Greece (MYTILINEOS SA), Turkey (ETI Aluminium), and Romania (ALUM SA) and two academic partners from Greece (National Technical University of Athens) and Turkey (Necmettin Erbacan University). We present preliminary characterization results of three different BR samples that originate from the three aluminium industries, in respect of bulk chemical analysis (XRF, ICP), mineralogical investigation (XRD), and morphological observation through microscopy.

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