Sustainable Supply of Scandium for the EU Industries from Liquid Iron Chloride Based TiO2 Plants

Yagmurlu, Bengi; Orberger, B.; Dittrich, Carsten; Croisé, Georges; Scharfenberg, Robin; Balomenos, Efthymios; Panias, Dimitrios; Mikeli, Eleni; Maier, C.E.; Schneider, R. T.; Friedrich, Bernd; Dräger, Philipp; Baumgärtner, Frank; Schmitz, Martin; Letmathe, Peter; Sakkas, Konstantinos; Georgopoulos, Christos; Laan, Henk van den

doi:10.3390/materproc2021005086

Cited by 6 publications

(6 citation statements)

References 23 publications

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“…The precipitate is first calcined to obtain Sc 2 O 3 and subsequently fluorinated with hydrofluoric acid (HF) to finally obtain ScF 3 . Alternative methods to directly obtain ScF 3 without using HF have recently been developed …”

Section: Introductionmentioning

confidence: 99%

“…Alternative methods to directly obtain ScF 3 without using HF have recently been developed. 9 From a fundamental viewpoint, ScF 3 has received considerable interest in the past few years because of its negative thermal expansion, namely, its remarkable ability to shrink when heated. 10−17 This property is closely related to the electronic structure of this material and the crystallographic arrangement of the two atomic species therein: Upon heating, F atoms oscillate around their bonds, with Sc leading to an overall contraction of the crystalline volume.…”

Section: ■ Introductionmentioning

confidence: 99%

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Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs

et al. 2023

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Microscopic knowledge of the structural, energetic, and electronic properties of scandium fluoride is still incomplete despite the relevance of this material as an intermediate for the manufacturing of Al–Sc alloys. In a work based on first-principles calculations and X-ray spectroscopy, we assess the stability and electronic structure of six computationally predicted ScF3 polymorphs, two of which correspond to experimentally resolved single-crystal phases. In the theoretical analysis based on density functional theory (DFT), we identify similarities among the polymorphs based on their formation energies, charge-density distribution, and electronic properties (band gaps and density of states). We find striking analogies between the results obtained for the low- and high-temperature phases of the material, indirectly confirming that the transition occurring between them mainly consists of a rigid rotation of the lattice. With this knowledge, we examine the X-ray absorption spectra from the Sc and F K-edge contrasting first-principles results obtained from the solution of the Bethe–Salpeter equation on top of all-electron DFT with high-energy-resolution fluorescence detection measurements. Analysis of the computational results sheds light on the electronic origin of the absorption maxima and provides information on the prominent excitonic effects that characterize all spectra. A comparison with measurements confirms that the sample is mainly composed of the high- and low-temperature polymorphs of ScF3. However, some fine details in the experimental results suggest that the probed powder sample may contain defects and/or residual traces of metastable polymorphs.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs

et al. 2023

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“…Afterward, TiCl 4 is converted to pure TiO 2 and Cl 2 , the latter being recycled. Chlorides of accompanying metals enter the scrubbing water, which eventually turns into a semiconcentrated HCl slurry containing unreacted ore, coal particles, and numerous dissolved metals. , Among these, Sc is in the hundred ppm range, making TiO 2 acid waste a promising Sc resource …”

Section: Introductionmentioning

confidence: 99%

“…Chlorides of accompanying metals enter the scrubbing water, which eventually turns into a semiconcentrated HCl slurry containing unreacted ore, coal particles, and numerous dissolved metals. 13,14 Among these, Sc is in the hundred ppm range, making TiO 2 acid waste a promising Sc resource. 3 Solvent extraction (SX) is the most commonly used technique to separate and concentrate Sc from aqueous solutions.…”

Section: ■ Introductionmentioning

confidence: 99%

Nanofiltration-Enhanced Solvent Extraction of Scandium from TiO₂ Acid Waste

Hedwig

Yagmurlu

Huang

et al. 2022

ACS Sustainable Chem. Eng.

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Scandium is a critical raw material with a technological potential to reduce transportation costs and CO 2 emissions. However, global supply and market adoption are crucially impaired by the lack of high-grade Sc ores and recovery strategies. A tandem nanofiltration solvent extraction route is demonstrated to enable effective Sc recovery from real-world acid waste from the chloride TiO 2 production route. The process involving several filtration stages, solvent extraction, and precipitation was optimized, ultimately producing >97% pure (NH 4 ) 3 ScF 6 .

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“…Yagmurlu et al [ 113 ] explained the potential of Sc recovery from a liquid containing iron chloride in the TiO 2 production plants by the ScaVanger project. Additionally, the revolutionary ScaVanger processing method presents a comprehensive, viable, more environmentally friendly, and customizable process for generating Sc, Nb, and V compounds.…”

Section: Processes For Scandium Recovery From Various Sourcesmentioning

confidence: 99%

Scandium Recovery Methods from Mining, Metallurgical Extractive Industries, and Industrial Wastes

et al. 2022

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The recovery of scandium (Sc) from wastes and various resources using solvent extraction (SX) was discussed in detail. Moreover, the metallurgical extractive procedures for Sc recovery were presented. Acidic and neutral organophosphorus (OPCs) extractants are the most extensively used in industrial activities, considering that they provide the highest extraction efficiency of any of the valuable components. Due to the chemical and physical similarities of the rare earth metals, the separation and purification processes of Sc are difficult tasks. Sc has also been extracted from acidic solutions using carboxylic acids, amines, and acidic β-diketone, among other solvents and chemicals. For improving the extraction efficiencies, the development of mixed extractants or synergistic systems for the SX of Sc has been carried out in recent years. Different operational parameters play an important role in the extraction process, such as the type of the aqueous phase and its acidity, the aqueous (A) to organic (O) and solid (S) to liquid (L) phase ratios, as well as the type of the diluents. Sc recovery is now implemented in industrial production using a combination of hydrometallurgical and pyrometallurgical techniques, such as ore pre-treatment, leaching, SX, precipitation, and calcination. The hydrometallurgical methods (acid leaching and SX) were effective for Sc recovery. Furthermore, the OPCs bis(2-ethylhexyl) phosphoric acid (D2EHPA/P204) and tributyl phosphate (TBP) showed interesting potential taking into consideration some co-extracted metals such as Fe(III) and Ti(IV).

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Sustainable Supply of Scandium for the EU Industries from Liquid Iron Chloride Based TiO2 Plants

Cited by 6 publications

References 23 publications

Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs

Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs

Nanofiltration-Enhanced Solvent Extraction of Scandium from TiO₂ Acid Waste

Scandium Recovery Methods from Mining, Metallurgical Extractive Industries, and Industrial Wastes

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Sustainable Supply of Scandium for the EU Industries from Liquid Iron Chloride Based TiO2 Plants

Cited by 6 publications

References 23 publications

Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs

Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs

Nanofiltration-Enhanced Solvent Extraction of Scandium from TiO2 Acid Waste

Scandium Recovery Methods from Mining, Metallurgical Extractive Industries, and Industrial Wastes

Contact Info

Product

Resources

About

Nanofiltration-Enhanced Solvent Extraction of Scandium from TiO₂ Acid Waste